Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high altitudes.To test the hypothesis ...Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high altitudes.To test the hypothesis that protein abundance and phosphorylation change in response to winter hibernation,we conducted a comprehensive and quantitative proteomic and phosphoproteomic analysis of the liver of the Xizang plateau frog,Nanorana parkeri,living on the Qinghai-Xizang Plateau.In total,5170 proteins and 5695 phosphorylation sites in 1938 proteins were quantified.Based on proteomic analysis,674 differentially expressed proteins(438 up-regulated,236 down-regulated)were screened in hibernating N.parkeri versus summer individuals.Functional enrichment analysis revealed that higher expressed proteins in winter were significantly enriched in immune-related signaling pathways,whereas lower expressed proteins were mainly involved in metabolic processes.A total of 4251 modified sites(4147 up-regulated,104 down-regulated)belonging to 1638 phosphoproteins(1555 up-regulated,83 down-regulated)were significantly changed in the liver.During hibernation,RPP regulated a diverse array of proteins involved in multiple functions,including metabolic enzymatic activity,ion transport,protein turnover,signal transduction,and alternative splicing.These changes contribute to enhancing protection,suppressing energy-consuming processes,and inducing metabolic depression.Moreover,the activities of phosphofructokinase,glutamate dehydrogenase,and ATPase were all significantly lower in winter compared to summer.In conclusion,our results support the hypothesis and demonstrate the importance of RPP as a regulatory mechanism when animals transition into a hypometabolic state.展开更多
The effects of 5 mg/L 1,2,4-trichlorobenzene (TCB) and 0.1 mmol/L mercury ion (Hg^2+) stresses on Ca^2+ fluxion and protein phosphorylation in rice seedlings were investigated by isotope exchange kinetics and in...The effects of 5 mg/L 1,2,4-trichlorobenzene (TCB) and 0.1 mmol/L mercury ion (Hg^2+) stresses on Ca^2+ fluxion and protein phosphorylation in rice seedlings were investigated by isotope exchange kinetics and in vitro phosphorylation assay. The Ca^2+ absorption in rice leaves and Ca^2+ transportation from roots to leaves were promoted significantly in response to Hg^2+ and TCB treatments for 4-48 h. The Ca^2+ absorption peaks presented in the leaves when the rice seedlings were exposed to Hg^2+ for 8-12 h or to TCB for 12-24 h. Several Ca^2+ absorption peaks presented in the roots during rice seedlings being exposed to Hg^2+ and TCB, and the first Ca^2+ absorption peak was at 8 h after being exposed to Hg^2+ and TCB The result of isotope exchange kinetic analysis confirmed that short-term (8 h) Hg^2+ and TCB stresses caused Ca^2+ channels or pumps located on plasmalemma to open transiently. The phosphorylation assay showed that short-term TCB stress enhanced protein phosphorylation in rice roots (TCB treatment for 4-8 h) and leaves (TCB treatment for 4-24 h), and short-term (4-8 h) Hg^2+ stress also enhanced protein phosphorylation in rice leaves. The enhancement of protein phosphorylation in both roots and leaves corresponded with the first Ca^2+ absorption peak, which confirmed that the enhancement of protein phosphorylation caused by TCB or Hg^2+ stress might be partly triggered by the increases of cytosolic calcium. TCB treatment over 12 h inhibited protein phosphorylation in rice roots, which might be partly due to that TCB stress suppressed the protein kinase activity. Whereas, Hg^2+ treatment inhibited protein phosphorylation in rice roots, and Hg^2+ treatment over 12 h inhibited protein phosphorylation in rice leaves. This might be attributed to that not only the protein kinase activity, but also the expressions of phosphorylation proteins were restrained by Hg^2+ stress.展开更多
The objective of this study was to investigate the effect of lairage after transport on post mortem muscle glycolysis,protein phosphorylation and lamb meat quality.Two preslaughter animal treatments,transport for 3 h ...The objective of this study was to investigate the effect of lairage after transport on post mortem muscle glycolysis,protein phosphorylation and lamb meat quality.Two preslaughter animal treatments,transport for 3 h and lairage for 0 h(T3L0)and transport for 3 h and then lairage for 12 h(T3L12),were compared with a control treatment of 0 h transport and 0 h lairage.Data obtained showed that preslaughter transport had a significant effect on lamb meat quality.Loins from lambs of the T3L0 treatment showed higher(P=0.026)pH24 h and higher(P=0.021)pH48 h values,but lower(P〈0.001)drip loss and lower(P〈0.05)glycolytic potential at 0 h post mortem than those of the T3L12 and control groups.Muscle samples of the T3L0 group showed higher(P=0.046)shear force and lower(P=0.005)b* value than those of the T3L12 group.Muscle glycogen concentration at 0,2,4 h post mortem were lower(P〈0.05)in the T3L0 group than in control.No significant difference(P〉0.05)in most meat quality parameters was determined between the T3L12 group and control,showing lairage for 12 h allowed lambs to recover from the effects of transport for 3 h and resulted in similar meat quality characteristics compared to no transport.Lairage after transport did not affect most meat quality indices in comparison with control,but increased the meat drip loss and b*value of lambs possibly through decreasing glycogen concentration and glycolytic potential.展开更多
Phosphosites in the human proteome represent an excellent source of potential biomarkers of pesticide toxicity. In fact, experimental animal models as well as in vitro studies have revealed phosphorylation disruption ...Phosphosites in the human proteome represent an excellent source of potential biomarkers of pesticide toxicity. In fact, experimental animal models as well as in vitro studies have revealed phosphorylation disruption associated to metabolic regulation, hormone signaling, neuronal function and differentiation, cell survival and death. Due to their estrogen-mimicking ability, pesticides are considered as prime etiological suspects of increasing tumor incidence. Evidences of alterations in the signal transduction pathways involved in the tumor progression stage of pesticides were also provided. Despite progress in understanding the effect of pesticides on the human phosphorproteome and their health outcomes, it remains a complex issue to be studied. By now, the potential impact of pesticides in epigenetic phosphorylation pathways remains poorly explored. In addition, studies involving pesticides mixtures effects are needed. This review updates and provides a comprehensive discussion on the molecular and biochemical events underlying protein phosphorylation pathway disruption caused by pesticides most frequently detected in human tissues and fluids, such as organochlorine pesticides and organophosphates. The link between epidemiological studies and experimental approaches is also considered. Future challenges, such as micro-array phosphoproteome studies to complement gene expression arrays to understand the mechanisms involved in pesticide toxicology are briefly discussed.展开更多
Phosphorylation of protein is an important post-translational modification that enables activation of various enzymes and receptors included in signaling pathways. To reduce the cost of identifying phosphorylation sit...Phosphorylation of protein is an important post-translational modification that enables activation of various enzymes and receptors included in signaling pathways. To reduce the cost of identifying phosphorylation site by laborious experiments, computational prediction of it has been actively studied. In this study, by adopting a new set of features and applying feature selection by Random Forest with grid search before training by Support Vector Machine, our method achieved better or comparable performance of phosphorylation site prediction for two different data sets.展开更多
Fungal endophytes have been isolated from almost every plant, infecting their hosts without causing visible disease symptoms, and yet have still proved to be involved in plant secondary metabolites accumulation. To de...Fungal endophytes have been isolated from almost every plant, infecting their hosts without causing visible disease symptoms, and yet have still proved to be involved in plant secondary metabolites accumulation. To decipher the possible physiological mechanisms of the endophytic fungus-host interaction, the role of protein phosphorylation and the relationship between endophytic fungus-induced kinase activity and nitric oxide (NO) and brassinolide (BL) in endophyte-enhanced volatile oil accumulation in Atractylodes lancea plantlets were investigated using pharmacological and biochemical approaches. Inoculation with the endophytic fungus Gilmaniella sp. ALl2 enhanced the activities of total protein phosphorylation, Ca2^-dependent protein kinase, and volatile oil accumulation in A. lancea plantlets. The upregulation of protein kinase activity could be blocked by the BL inhibitor brassinazole. Furthermore, pretreatments with the NO-specific scavenger cPTIO significantly reduced the increased activities of protein kinases in A. lancea plantlets inoculated with endophytic fungus. Pretreatments with different protein kinase inhibitors also reduced fungus-induced NO production and volatile oil accumulation, but had barely no effect on the BL level. These data suggest that protein phosphorylation is required for endophyte- induced volatile oil production in A. lancea plantlets, and that crosstalk between protein phosphorylation and the NO pathway may occur and act as a downstream signaling event of the BL pathway.展开更多
Using pharmacological and biochemical approaches, the role of protein phosphorylation and the interrelationship between water stress-enhanced kinase activity, antioxidant enzyme activity, hydrogen peroxide (H202) ac...Using pharmacological and biochemical approaches, the role of protein phosphorylation and the interrelationship between water stress-enhanced kinase activity, antioxidant enzyme activity, hydrogen peroxide (H202) accumulation and endogenous abscisic acid in maize (Zea mays L.) leaves were investigated. Water-stress upregulated the activities of total protein phosphorylation and Ca^2+-dependent protein kinase, and the upregulation was blocked in abscisic aciddeficient vp5 mutant. Furthermore, pretreatments with a nicotinamide adenine dinucleotide phosphate oxidase inhibitor and a scavenger of H2O2 significantly reduced the increased activities of total protein kinase and Ca^2+-dependent protein kinase in maize leaves exposed to water stress. Pretreatments with different protein kinase inhibitors also reduced the water stress-induced H2O2 production and the water stress-enhanced activities of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase. The data suggest that protein phosphorylation and H2O2 generation are required for water stress-induced antioxidant defense in maize leaves and that crosstalk between protein phosphorylation and H2O2 generation may occur.展开更多
Increasing evidence shows that protein phosphorylation on serine, threonine and tyrosine residues is a major regulatory post-translational modification in the bacteria. This review focuses on the implications of bacte...Increasing evidence shows that protein phosphorylation on serine, threonine and tyrosine residues is a major regulatory post-translational modification in the bacteria. This review focuses on the implications of bacterial phosphoproteome in bacterial pathogenicity and highlights recent development of methods in phosphoproteomics and the connectivity of the phosphorylation networks. Recent technical developments in the high accuracy mass spectrometry have dramatically transformed proteomics and made it possible the characterization of a few exhaus- tive site-specific bacterial phosphoproteomes. The high abundance of tyrosine phosphorylations in a few bacterial phosphoproteomes suggests their roles in the pathogenicity, especially in the case of pathogen-host interactions; the high abundance of multi-phosphorylation sites in bacterial phosphoprotein is a compensation of the relatively small phosphorylation size and an indicator of the delicate regulation of protein functions.展开更多
The uptake of ammonium,nitrate,phosphorus,and potassium ions by roots is mediated by specific ion transporter or channel proteins,and protein phosphorylation regulation events occurring on these proteins and their reg...The uptake of ammonium,nitrate,phosphorus,and potassium ions by roots is mediated by specific ion transporter or channel proteins,and protein phosphorylation regulation events occurring on these proteins and their regulators determine their ultimate activity.Elucidating the mechanism by which protein phosphorylation modification regulates nutrient uptake will advance plant breeding for high nutrientuse efficiency.In this review,it is concluded that the root nutrient absorption system is composed of several,but not all,members of a specific ion transporter or channel family.Under nutrient-starvation conditions,protein phosphorylation-based regulation of these proteins and associated transcription factors increases ion transporter-or channel-mediated nutrient uptake capacity via direct function activity enhancement,allowing more protein trafficking to the plasma membrane,by strengthening the interaction of transporters and channels with partner proteins,by increasing their protein stability,and by transcriptional activation.Under excessive nutrient conditions,protein phosphorylation-based regulation suppresses nutrient uptake by reversing these processes.Strengthening phosphorylation regulation items that increase nutrient absorption and weakening phosphorylation modification items that are not conducive to nutrient absorption show potential as strategies for increasing nutrient use efficiency.展开更多
Monochamus alternatus Hope (Coleoptera: Cerambycidae) is not only a serious pest insect to pine trees but also the main vector of pine wood nemadote Bursaphelenchus xylophilus, which causes pine wilt disease. To ex...Monochamus alternatus Hope (Coleoptera: Cerambycidae) is not only a serious pest insect to pine trees but also the main vector of pine wood nemadote Bursaphelenchus xylophilus, which causes pine wilt disease. To explore the insecticidal mechanism of insecticides to M. alternatus, we chose methamidophos and deltamethrin as the representatives of two groups of insecticides (organophosphates and pyrethroids), which are widely used for pest control in China and investigated their effects on phosphorylation of proteins from the insect. Phosphorylation of proteins from the insect fat body and head was determined by in vitro 32P-labelling. In the fat body, deltamethrin obviously reduced basal phosphorylation levels of proteins at 111, 95, 77, and 44 kDa, but enhanced the basal phosphorylation level of a protein at 138 kDa. However, in the presence of calmodulin but not cyclic adenosine monophosphate (cAMP), deltamethrin increased phosphorylation of the protein at 111 kDa. In the head, deltamethrin inhibited basal phosphorylation levels of proteins at 113, 98, and 51 kDa, but potentiated phosphorylation of a protein at 167 kDa activated by cAMP. Methamidophos inhibited phosphorylation of a protein at 44 kDa in the fat body. Although methamidophos did not impact basal phosphorylation levels of any proteins in the head, it inhibited calcium/calmodulin (Ca^2+CaM)-stimulated phosphorylation of a protein at 51 kDa. Together, our data indicate that methamidophos and deltamethrin altered phosphorylation levels of various proteins in the head and fat body of the pine insect and these two kinds of insecticides acted on the proteins that can be phosphorylated in the tissues respectively, which is possibly related to their toxicity.展开更多
Protein phosphorylation/dephosphorylation is the central mechanism of post-translational modification which regulates cellular responses and phenotypes. Due to the efficiency and resource constraints of the in vivo me...Protein phosphorylation/dephosphorylation is the central mechanism of post-translational modification which regulates cellular responses and phenotypes. Due to the efficiency and resource constraints of the in vivo methods for identifying phosphorylation sites, there is a strong motivation to computationally predict potential phosphorylation sites. In this work, we propose to use a unique set of features to represent the peptides surrounding the amino acid sites of interest and use feature selection support vector machine to predict whether the serine/threonine sites are potentially phosphorylable, as well as selecting important features that may lead to phosphorylation. Experimental results indicate that the new features and the prediction method can more effectively predict protein phosphorylation sites than the existing state of the art methods. The features selected by our prediction model provide biological insights to the in vivo phosphorylation.展开更多
This study aimed to examine changes in phosphorylation of sarcoplasmic and myofibrillar proteins from longissimus lumborum,semitendinosus,and psoas major muscles during postmortem ageing for 5 d.These sarcoplasmic and...This study aimed to examine changes in phosphorylation of sarcoplasmic and myofibrillar proteins from longissimus lumborum,semitendinosus,and psoas major muscles during postmortem ageing for 5 d.These sarcoplasmic and myofibrillar proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and stained with phosphorous and protein specific stains.Myofibril fragmentation index,pH,the content of lactic acid and the relative activity of μ-calpain in three ovine muscles were measured.These results showed that the relative phosphorylation level of sarcoplasmic and myofibrillar proteins of psoas major muscle were lower compared with longissimus lumborum and semitendinosus muscles(P<0.05).The pH of psoas major muscle was the lowest at 0.5 h postmortem,and the highest after 12 h postmortem(P<0.05).In addition,the relative activity of μ-calpain was higher within 5 d postmortem and myofibril fragmentation index was higher after 1 d postmortem in psoas major muscle than those of longissimus lumborum and semitendinosus muscles(P<0.05).The sarcoplasmic protein phosphorylation may regulate the rate of pH decline to influence the μ-calpain activity and then proteolysis of proteins consequently.This study gives a new perspective of the mechanism of postmortem meat tenderization.展开更多
AIM: To investigate the effect of Golgi phosphorylation protein 3(GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer(CRC). METHODS: The expression of GOLPH3 in CRC tissues and normal...AIM: To investigate the effect of Golgi phosphorylation protein 3(GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer(CRC). METHODS: The expression of GOLPH3 in CRC tissues and normal colorectal mucosae was determined by immunohistochemistry in 62 patients. In addition, immunohistochemistry was also carried out to detect the expression of vascular endothelial growth factor(VEGF), CD34 and microvessel density(MVD). Terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling assay was used to determine the apoptotic index(AI). The Kaplan-Meier method was used to analyze the relationship between GOLPH3 expression and survival in another 123 CRC cases.RESULTS: Compared with normal colorectal mucosae, a notably higher level of GOLPH3 protein expression was identified in CRC tissues(53.2% vs 24.2%, P < 0.05). Positive GOLPH3 expression was significantly associated with tumor invasion depth, TNM stage, and lymph node metastasis(P = 0.001; P = 0.020; P = 0.020; P < 0.05, respectively), but not with tumor length, tumor site, and age(P = 0.363; P = 0.819; P = 0.599; P > 0.05, respectively). VEGF expression and MVD in GOLPH3-positive CRC was significantly higher than in GOLPH3-negative CRC(VEGF: 69.7% vs 31.0%; MVD: 21.45 ± 9.39 vs 14.24 ± 8.97; P < 0.05).GOLPH3 expression was negatively correlated with AI in CRC as shown by Spearman correlation analysis(r =-0.320, P < 0.05). The 5-year survival rate in GOLPH3-negative CRC(69.4%) was significantly higher than in GOLPH3-positive CRC(48.6%)(log-rank test, P < 0.05).CONCLUSION: High expression of GOLPH3 is found in CRC tissues. GOLPH3 expression may be a novel prognostic marker for CRC patients.展开更多
Objective:To identify the alteration of tyrosine phosphorylated protein expression in rats with polycystic ovary syndrome(PCOS).Methods:Sixteen female Sprague-Dawley rats were divided into the control and letrozole-in...Objective:To identify the alteration of tyrosine phosphorylated protein expression in rats with polycystic ovary syndrome(PCOS).Methods:Sixteen female Sprague-Dawley rats were divided into the control and letrozole-induced PCOS groups.The oestrus cycle of rats was performed by vaginal smear.Sex hormones and morphology of the ovary,oviduct,and uterus were observed.Expressions and intensity of androgen receptor and tyrosine phosphorylated proteins of reproductive organs were investigated by Western blot.Results:Various polycysts and increased androgen receptor expression were present in the ovary of the PCOS group.The levels of follicle-stimulating hormone and testosteone were significantly higher in the PCOS group while progesterone and estradiol levels were significantly decreased as compared with the control group(P<0.05).Only the size of uterus in the PCOS group was significantly smaller than the control group.However,the density of collagen fibers observed in PCOS uterus was greater than the control group.Moreover,tyrosine phosphorylated proteins were significantly overexpressed in ovary(52,42,and 28 kDa),oviduct(72,56,42,and 28 kDa),and uterus(53 and 42 kDa)of the PCOS group compared to the control group.Conclusions:Presence of tyrosine phosphorylated proteins in the ovary,oviduct and uterus suggests that overexpression of tyrosine phosphorylated proteins may be involved in potential mechanism of female infertility especially in PCOS.展开更多
At 8 weeks after intragastric administration of icariin to senescence-accelerated mice (P8 strain), Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increa...At 8 weeks after intragastric administration of icariin to senescence-accelerated mice (P8 strain), Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse.展开更多
[Objectives] To study the effects and mechanism of notoginsenoside Rg1 on the spatial learning and memory and phosphorylated tau protein in the AD( Alzheimer's Disease) model rat. [Methods]The AD model rat was rep...[Objectives] To study the effects and mechanism of notoginsenoside Rg1 on the spatial learning and memory and phosphorylated tau protein in the AD( Alzheimer's Disease) model rat. [Methods]The AD model rat was replicated by injection of Aβ_(25-35) in the left lateral ventricles of SD rats. The low dose( 25 mg/kg),middle dose( 50 mg/kg) and high dose( 100 mg/kg) notoginsenoside Rg1 was used for intragastric administration,respectively,two times every day. After 4 weeks,the Morris water maze test was done to detect the learning and memory capacity,and the immunoblotting,immunohistochemical methods were used to detect the changes in the phosphorylation level and distribution of tau protein in hippocampus of the rats. [Results] After the intracerebroventricular injection of Aβ_(25-35),the learning and memory capacity of the model rats was significantly lower than the learning and memory capacity of the normal control rats. The immunoblotting test results showed that the phosphorylation level of tau protein threonine 231 site( Thr231) in hippocampus was significantly increased,and the nonphosphorylation level was significantly decreased. The morphological testing results showed that the phosphorylation level of tau protein Thr231 of AD model rats was increased markedly in region of DG,CA1 and CA3 of the hippocampus. The intervention of the middle dose notoginsenoside Rg1 could significantly improve the learning and memory capacity of the model rats in Morris water maze. The notoginsenoside Rg1 in three different doses could all reduce the phosphorylation level of tau protein Thr231 in the hippocampal DG,CA1,CA3 regions,and there were no significant differences among the three doses. [Conclusions]The notoginsenoside Rg1 could improve Aβ_(25-35)-induced spatial learning and memory impairment of the AD model rats,and decreased the phosphorylation level of tau protein in hippocampus.展开更多
Transient brain ischemia has been shown to induce hyperphosphorylation of the micro- tubule-associated protein tau. To further determine the mechanisms underlying these processes, we investigated the interaction betwe...Transient brain ischemia has been shown to induce hyperphosphorylation of the micro- tubule-associated protein tau. To further determine the mechanisms underlying these processes, we investigated the interaction between tau, glycogen synthase kinase (GSK)-313 and protein phos- phatase 2A. The results confirmed that tau protein was dephosphorylated during brain ischemia; in addition, the activity of GSK-3β was increased and the activity of protein phosphatase 2A was de- creased. After reperfusion, tau protein was hyperphosphorylated, the activity of GSK-3β was de- creased and the activity of protein phosphatase 2A remained low. Importantly, the interaction of tau with GSK-3β and protein phosphatase 2A was altered during ischemia and reperfusion. Lithium chloride could affect tau phosphorylation by regulating the interaction of tau with GSK-3β and pro- tein phosphatase 2A, and improve learning and memory ability of rats after transient brain ischemia. The present study demonstrated that it was the interaction of tau with GSK-3β and protein phos- phatase 2A, rather than their individual activities, that dominates the phosphorylation of tau in tran- sient brain ischemia. Hyperphosphorylated tau protein may play an important role in the evolution of brain injury in ischemic stroke. The neuroprotective effects of lithium chloride partly depend on the inhibition of tau phosphorylation during transient brain ischemia.展开更多
BACKGROUND: The differential diagnosis of many neurodegenerative disorders depends primarily on clinical symptoms together with imaging methods. Recently, increased importance has been placed on the use of biomarkers...BACKGROUND: The differential diagnosis of many neurodegenerative disorders depends primarily on clinical symptoms together with imaging methods. Recently, increased importance has been placed on the use of biomarkers for diagnosing various neurodegenerative disorders. OBJECTIVE: To assess the feasibility of tau-protein, phosphorylated tau-protein, beta-amyloid 42 (Aβ42), and 14-3-3 protein as biomarkers for diagnosing several neurodegenerative diseases complicated by cognitive deficits. DESIGN, TIME AND SETTING: A non-randomized, concurrent, case-control investigation was performed in three medical centers in the Czech Republic (Department of Neurology at the University Hospital in Hradec Kralove, Department of Neurology at the 2rd Medical Faculty, and the University Hospital Motol) between October 2000 and November 2006. PARTICIPANTS: Eighteen patients with probable AIzheimer's disease, 4 patients with Creutzfeldt-Jakob disease, 10 patients with frontotemporal dementia, 9 patients with clinically isolated syndrome suggestive of multiple sclerosis, and 7 patients with multiple sclerosis, as well as 38 race-, nationality-, and age-matched cognitively intact controls, were included in the study. Diagnoses were established based on the following criteria: the criteria for Alzheimer's disease proposed by the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association, WHO criteria for Creutzfeldt-Jakob disease, Neary criteria for frontotemporal dementia, and McDonald's criteria for multiple sclerosis. All included patients were confirmed to suffer from various degrees of dementia. METHODS: Enzyme-linked immunosorbent assay was used to measure concentrations of tau-protein, phosphorylated tau-protein, and Aβ42 in cerebrospinal fluid (CSF) samples collected by standard lumbar puncture from each patient. Moreover, 14-3-3 protein was assessed by Western blot in CSF of Creutzfeldt-Jakob disease patients. Cognitive status was assessed using the Mini Mental Scale Examination (MMSE) in all subjects. MAIN OUTCOME MEASURES: Establishment of biomarkers with greatest specificity and sensitivity for the investigated disorders according to Receiver Operating Characteristic curves, which were based on values from patients and controls; correlation between concentrations of given biomarkers and demographic parameters, diagnosis, duration of disease, and level of cognitive deficit. RESULTS: Increased concentrations of total tau protein and phosphorylated tau protein, and decreased levels of Aβ42, in CSF of Alzheimer's disease patients reached the required sensitivity/specificity ratio of 80% or greater. A marked elevation in CSF concentrations of total tau protein showed even greater sensitivity than 14-3-3 protein in Creutzfeldt-Jakob disease. There was no association between selected biomarkers and frontotemporal dementia or multiple sclerosis. Phosphorylated tau-protein was the only biomarker that noticeably correlated with MMSE scores for Alzheimer's disease.CONCLUSION: Levels of total tau protein, phosphorylated tau protein, and A!342 in the CSF could differentiate patients with Alzheimer's disease and Creutzfeldt-Jakob disease from healthy controls and patients with other neurodegenerative disorders. The diversity of absolute values demonstrates the necessity to establish a specific standard for each laboratory.展开更多
In order to investigate ATM in mediating DNA damage signal to p53 in the cellular response to IR, kinase activities of ATM and c-Abl immunoprecipitates and its activation by IR and damaged DNA have been analyzed. Resu...In order to investigate ATM in mediating DNA damage signal to p53 in the cellular response to IR, kinase activities of ATM and c-Abl immunoprecipitates and its activation by IR and damaged DNA have been analyzed. Results demonstrate that deficient ATM caused failure to activate phosphorylation of many proteins in response to radiation . ATM展开更多
The immunoregulatory effect of TLSFJM on the expression of T cell IL- 2R and protein tyrosine phosphorylation ( PTP ) was investigated by immunohistochemistry technique. The results showed that TLSFJMcan markedly supp...The immunoregulatory effect of TLSFJM on the expression of T cell IL- 2R and protein tyrosine phosphorylation ( PTP ) was investigated by immunohistochemistry technique. The results showed that TLSFJMcan markedly suppress the expression of IL-2R and PTP on PHA or TPA-stimulated human PBMC and murine IL-2 dependent cell line CTLL-2. However, there was no effect of TLSFJMon the production of IL-1, IL-2 and IL-6 that play an important role in the course of T lymphocyte proliferation and differentiation.展开更多
基金supported by the National Natural Science Foundation of China(32001110)Training Program for Cultivating Highlevel Talents by the China Scholarship Council(2021lxjjw01)Open Project of State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University(2021-KF-004)。
文摘Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high altitudes.To test the hypothesis that protein abundance and phosphorylation change in response to winter hibernation,we conducted a comprehensive and quantitative proteomic and phosphoproteomic analysis of the liver of the Xizang plateau frog,Nanorana parkeri,living on the Qinghai-Xizang Plateau.In total,5170 proteins and 5695 phosphorylation sites in 1938 proteins were quantified.Based on proteomic analysis,674 differentially expressed proteins(438 up-regulated,236 down-regulated)were screened in hibernating N.parkeri versus summer individuals.Functional enrichment analysis revealed that higher expressed proteins in winter were significantly enriched in immune-related signaling pathways,whereas lower expressed proteins were mainly involved in metabolic processes.A total of 4251 modified sites(4147 up-regulated,104 down-regulated)belonging to 1638 phosphoproteins(1555 up-regulated,83 down-regulated)were significantly changed in the liver.During hibernation,RPP regulated a diverse array of proteins involved in multiple functions,including metabolic enzymatic activity,ion transport,protein turnover,signal transduction,and alternative splicing.These changes contribute to enhancing protection,suppressing energy-consuming processes,and inducing metabolic depression.Moreover,the activities of phosphofructokinase,glutamate dehydrogenase,and ATPase were all significantly lower in winter compared to summer.In conclusion,our results support the hypothesis and demonstrate the importance of RPP as a regulatory mechanism when animals transition into a hypometabolic state.
基金supported by the National Natural Science Foundation of China(Grant No.30300026).
文摘The effects of 5 mg/L 1,2,4-trichlorobenzene (TCB) and 0.1 mmol/L mercury ion (Hg^2+) stresses on Ca^2+ fluxion and protein phosphorylation in rice seedlings were investigated by isotope exchange kinetics and in vitro phosphorylation assay. The Ca^2+ absorption in rice leaves and Ca^2+ transportation from roots to leaves were promoted significantly in response to Hg^2+ and TCB treatments for 4-48 h. The Ca^2+ absorption peaks presented in the leaves when the rice seedlings were exposed to Hg^2+ for 8-12 h or to TCB for 12-24 h. Several Ca^2+ absorption peaks presented in the roots during rice seedlings being exposed to Hg^2+ and TCB, and the first Ca^2+ absorption peak was at 8 h after being exposed to Hg^2+ and TCB The result of isotope exchange kinetic analysis confirmed that short-term (8 h) Hg^2+ and TCB stresses caused Ca^2+ channels or pumps located on plasmalemma to open transiently. The phosphorylation assay showed that short-term TCB stress enhanced protein phosphorylation in rice roots (TCB treatment for 4-8 h) and leaves (TCB treatment for 4-24 h), and short-term (4-8 h) Hg^2+ stress also enhanced protein phosphorylation in rice leaves. The enhancement of protein phosphorylation in both roots and leaves corresponded with the first Ca^2+ absorption peak, which confirmed that the enhancement of protein phosphorylation caused by TCB or Hg^2+ stress might be partly triggered by the increases of cytosolic calcium. TCB treatment over 12 h inhibited protein phosphorylation in rice roots, which might be partly due to that TCB stress suppressed the protein kinase activity. Whereas, Hg^2+ treatment inhibited protein phosphorylation in rice roots, and Hg^2+ treatment over 12 h inhibited protein phosphorylation in rice leaves. This might be attributed to that not only the protein kinase activity, but also the expressions of phosphorylation proteins were restrained by Hg^2+ stress.
基金financial support from the National Agricultural Science and Technology Innovation Program in China
文摘The objective of this study was to investigate the effect of lairage after transport on post mortem muscle glycolysis,protein phosphorylation and lamb meat quality.Two preslaughter animal treatments,transport for 3 h and lairage for 0 h(T3L0)and transport for 3 h and then lairage for 12 h(T3L12),were compared with a control treatment of 0 h transport and 0 h lairage.Data obtained showed that preslaughter transport had a significant effect on lamb meat quality.Loins from lambs of the T3L0 treatment showed higher(P=0.026)pH24 h and higher(P=0.021)pH48 h values,but lower(P〈0.001)drip loss and lower(P〈0.05)glycolytic potential at 0 h post mortem than those of the T3L12 and control groups.Muscle samples of the T3L0 group showed higher(P=0.046)shear force and lower(P=0.005)b* value than those of the T3L12 group.Muscle glycogen concentration at 0,2,4 h post mortem were lower(P〈0.05)in the T3L0 group than in control.No significant difference(P〉0.05)in most meat quality parameters was determined between the T3L12 group and control,showing lairage for 12 h allowed lambs to recover from the effects of transport for 3 h and resulted in similar meat quality characteristics compared to no transport.Lairage after transport did not affect most meat quality indices in comparison with control,but increased the meat drip loss and b*value of lambs possibly through decreasing glycogen concentration and glycolytic potential.
文摘Phosphosites in the human proteome represent an excellent source of potential biomarkers of pesticide toxicity. In fact, experimental animal models as well as in vitro studies have revealed phosphorylation disruption associated to metabolic regulation, hormone signaling, neuronal function and differentiation, cell survival and death. Due to their estrogen-mimicking ability, pesticides are considered as prime etiological suspects of increasing tumor incidence. Evidences of alterations in the signal transduction pathways involved in the tumor progression stage of pesticides were also provided. Despite progress in understanding the effect of pesticides on the human phosphorproteome and their health outcomes, it remains a complex issue to be studied. By now, the potential impact of pesticides in epigenetic phosphorylation pathways remains poorly explored. In addition, studies involving pesticides mixtures effects are needed. This review updates and provides a comprehensive discussion on the molecular and biochemical events underlying protein phosphorylation pathway disruption caused by pesticides most frequently detected in human tissues and fluids, such as organochlorine pesticides and organophosphates. The link between epidemiological studies and experimental approaches is also considered. Future challenges, such as micro-array phosphoproteome studies to complement gene expression arrays to understand the mechanisms involved in pesticide toxicology are briefly discussed.
文摘Phosphorylation of protein is an important post-translational modification that enables activation of various enzymes and receptors included in signaling pathways. To reduce the cost of identifying phosphorylation site by laborious experiments, computational prediction of it has been actively studied. In this study, by adopting a new set of features and applying feature selection by Random Forest with grid search before training by Support Vector Machine, our method achieved better or comparable performance of phosphorylation site prediction for two different data sets.
基金the National Natural Science Foundation of China (No. 31070443 and No. 30970523)
文摘Fungal endophytes have been isolated from almost every plant, infecting their hosts without causing visible disease symptoms, and yet have still proved to be involved in plant secondary metabolites accumulation. To decipher the possible physiological mechanisms of the endophytic fungus-host interaction, the role of protein phosphorylation and the relationship between endophytic fungus-induced kinase activity and nitric oxide (NO) and brassinolide (BL) in endophyte-enhanced volatile oil accumulation in Atractylodes lancea plantlets were investigated using pharmacological and biochemical approaches. Inoculation with the endophytic fungus Gilmaniella sp. ALl2 enhanced the activities of total protein phosphorylation, Ca2^-dependent protein kinase, and volatile oil accumulation in A. lancea plantlets. The upregulation of protein kinase activity could be blocked by the BL inhibitor brassinazole. Furthermore, pretreatments with the NO-specific scavenger cPTIO significantly reduced the increased activities of protein kinases in A. lancea plantlets inoculated with endophytic fungus. Pretreatments with different protein kinase inhibitors also reduced fungus-induced NO production and volatile oil accumulation, but had barely no effect on the BL level. These data suggest that protein phosphorylation is required for endophyte- induced volatile oil production in A. lancea plantlets, and that crosstalk between protein phosphorylation and the NO pathway may occur and act as a downstream signaling event of the BL pathway.
基金Supported by the National Natural Science Foundation of China (90717108 and 30700491)the Open Project of the National Key Laboratory of Crop Genetics and Germplasm Enhancement of Nanjing Agricultural University(ZW2007002)
文摘Using pharmacological and biochemical approaches, the role of protein phosphorylation and the interrelationship between water stress-enhanced kinase activity, antioxidant enzyme activity, hydrogen peroxide (H202) accumulation and endogenous abscisic acid in maize (Zea mays L.) leaves were investigated. Water-stress upregulated the activities of total protein phosphorylation and Ca^2+-dependent protein kinase, and the upregulation was blocked in abscisic aciddeficient vp5 mutant. Furthermore, pretreatments with a nicotinamide adenine dinucleotide phosphate oxidase inhibitor and a scavenger of H2O2 significantly reduced the increased activities of total protein kinase and Ca^2+-dependent protein kinase in maize leaves exposed to water stress. Pretreatments with different protein kinase inhibitors also reduced the water stress-induced H2O2 production and the water stress-enhanced activities of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase. The data suggest that protein phosphorylation and H2O2 generation are required for water stress-induced antioxidant defense in maize leaves and that crosstalk between protein phosphorylation and H2O2 generation may occur.
基金supported by the National Natural Science Foundation of China(Grant No.20801061)Guangdong Natural Science Foundation(Grant No.8451027501001233)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Educationthe Fundamental Research Funds for the Central Universities(Grant No.10lgpy19)
文摘Increasing evidence shows that protein phosphorylation on serine, threonine and tyrosine residues is a major regulatory post-translational modification in the bacteria. This review focuses on the implications of bacterial phosphoproteome in bacterial pathogenicity and highlights recent development of methods in phosphoproteomics and the connectivity of the phosphorylation networks. Recent technical developments in the high accuracy mass spectrometry have dramatically transformed proteomics and made it possible the characterization of a few exhaus- tive site-specific bacterial phosphoproteomes. The high abundance of tyrosine phosphorylations in a few bacterial phosphoproteomes suggests their roles in the pathogenicity, especially in the case of pathogen-host interactions; the high abundance of multi-phosphorylation sites in bacterial phosphoprotein is a compensation of the relatively small phosphorylation size and an indicator of the delicate regulation of protein functions.
基金supported by the Jiangsu Provincial DoubleInnovation Doctor Program(JSSCBS20221643)the Jiangsu Institute of Botany Talent Fund(JIBTF202210)+2 种基金the Program for the Young Innovative Talents of Jiangsu Vocational College of Agriculture and Forest(2021kj26)the National Natural Science Foundation of China(32101429)Natural Science Foundation of Jiangsu Province,China(BK20200288)。
文摘The uptake of ammonium,nitrate,phosphorus,and potassium ions by roots is mediated by specific ion transporter or channel proteins,and protein phosphorylation regulation events occurring on these proteins and their regulators determine their ultimate activity.Elucidating the mechanism by which protein phosphorylation modification regulates nutrient uptake will advance plant breeding for high nutrientuse efficiency.In this review,it is concluded that the root nutrient absorption system is composed of several,but not all,members of a specific ion transporter or channel family.Under nutrient-starvation conditions,protein phosphorylation-based regulation of these proteins and associated transcription factors increases ion transporter-or channel-mediated nutrient uptake capacity via direct function activity enhancement,allowing more protein trafficking to the plasma membrane,by strengthening the interaction of transporters and channels with partner proteins,by increasing their protein stability,and by transcriptional activation.Under excessive nutrient conditions,protein phosphorylation-based regulation suppresses nutrient uptake by reversing these processes.Strengthening phosphorylation regulation items that increase nutrient absorption and weakening phosphorylation modification items that are not conducive to nutrient absorption show potential as strategies for increasing nutrient use efficiency.
文摘Monochamus alternatus Hope (Coleoptera: Cerambycidae) is not only a serious pest insect to pine trees but also the main vector of pine wood nemadote Bursaphelenchus xylophilus, which causes pine wilt disease. To explore the insecticidal mechanism of insecticides to M. alternatus, we chose methamidophos and deltamethrin as the representatives of two groups of insecticides (organophosphates and pyrethroids), which are widely used for pest control in China and investigated their effects on phosphorylation of proteins from the insect. Phosphorylation of proteins from the insect fat body and head was determined by in vitro 32P-labelling. In the fat body, deltamethrin obviously reduced basal phosphorylation levels of proteins at 111, 95, 77, and 44 kDa, but enhanced the basal phosphorylation level of a protein at 138 kDa. However, in the presence of calmodulin but not cyclic adenosine monophosphate (cAMP), deltamethrin increased phosphorylation of the protein at 111 kDa. In the head, deltamethrin inhibited basal phosphorylation levels of proteins at 113, 98, and 51 kDa, but potentiated phosphorylation of a protein at 167 kDa activated by cAMP. Methamidophos inhibited phosphorylation of a protein at 44 kDa in the fat body. Although methamidophos did not impact basal phosphorylation levels of any proteins in the head, it inhibited calcium/calmodulin (Ca^2+CaM)-stimulated phosphorylation of a protein at 51 kDa. Together, our data indicate that methamidophos and deltamethrin altered phosphorylation levels of various proteins in the head and fat body of the pine insect and these two kinds of insecticides acted on the proteins that can be phosphorylated in the tissues respectively, which is possibly related to their toxicity.
文摘Protein phosphorylation/dephosphorylation is the central mechanism of post-translational modification which regulates cellular responses and phenotypes. Due to the efficiency and resource constraints of the in vivo methods for identifying phosphorylation sites, there is a strong motivation to computationally predict potential phosphorylation sites. In this work, we propose to use a unique set of features to represent the peptides surrounding the amino acid sites of interest and use feature selection support vector machine to predict whether the serine/threonine sites are potentially phosphorylable, as well as selecting important features that may lead to phosphorylation. Experimental results indicate that the new features and the prediction method can more effectively predict protein phosphorylation sites than the existing state of the art methods. The features selected by our prediction model provide biological insights to the in vivo phosphorylation.
基金funded by the National Agricultural Science and Technology Innovation Program in China
文摘This study aimed to examine changes in phosphorylation of sarcoplasmic and myofibrillar proteins from longissimus lumborum,semitendinosus,and psoas major muscles during postmortem ageing for 5 d.These sarcoplasmic and myofibrillar proteins were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and stained with phosphorous and protein specific stains.Myofibril fragmentation index,pH,the content of lactic acid and the relative activity of μ-calpain in three ovine muscles were measured.These results showed that the relative phosphorylation level of sarcoplasmic and myofibrillar proteins of psoas major muscle were lower compared with longissimus lumborum and semitendinosus muscles(P<0.05).The pH of psoas major muscle was the lowest at 0.5 h postmortem,and the highest after 12 h postmortem(P<0.05).In addition,the relative activity of μ-calpain was higher within 5 d postmortem and myofibril fragmentation index was higher after 1 d postmortem in psoas major muscle than those of longissimus lumborum and semitendinosus muscles(P<0.05).The sarcoplasmic protein phosphorylation may regulate the rate of pH decline to influence the μ-calpain activity and then proteolysis of proteins consequently.This study gives a new perspective of the mechanism of postmortem meat tenderization.
基金Supported by The Scientific Research Fund from the Science and Technology Bureau of QuanzhouChinaNo.2010Z33
文摘AIM: To investigate the effect of Golgi phosphorylation protein 3(GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer(CRC). METHODS: The expression of GOLPH3 in CRC tissues and normal colorectal mucosae was determined by immunohistochemistry in 62 patients. In addition, immunohistochemistry was also carried out to detect the expression of vascular endothelial growth factor(VEGF), CD34 and microvessel density(MVD). Terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling assay was used to determine the apoptotic index(AI). The Kaplan-Meier method was used to analyze the relationship between GOLPH3 expression and survival in another 123 CRC cases.RESULTS: Compared with normal colorectal mucosae, a notably higher level of GOLPH3 protein expression was identified in CRC tissues(53.2% vs 24.2%, P < 0.05). Positive GOLPH3 expression was significantly associated with tumor invasion depth, TNM stage, and lymph node metastasis(P = 0.001; P = 0.020; P = 0.020; P < 0.05, respectively), but not with tumor length, tumor site, and age(P = 0.363; P = 0.819; P = 0.599; P > 0.05, respectively). VEGF expression and MVD in GOLPH3-positive CRC was significantly higher than in GOLPH3-negative CRC(VEGF: 69.7% vs 31.0%; MVD: 21.45 ± 9.39 vs 14.24 ± 8.97; P < 0.05).GOLPH3 expression was negatively correlated with AI in CRC as shown by Spearman correlation analysis(r =-0.320, P < 0.05). The 5-year survival rate in GOLPH3-negative CRC(69.4%) was significantly higher than in GOLPH3-positive CRC(48.6%)(log-rank test, P < 0.05).CONCLUSION: High expression of GOLPH3 is found in CRC tissues. GOLPH3 expression may be a novel prognostic marker for CRC patients.
基金This study was supported by Invitation Research Grant,Faculty of Medicine,Khon Kaen University,Thailand(Grant No.IN62336).
文摘Objective:To identify the alteration of tyrosine phosphorylated protein expression in rats with polycystic ovary syndrome(PCOS).Methods:Sixteen female Sprague-Dawley rats were divided into the control and letrozole-induced PCOS groups.The oestrus cycle of rats was performed by vaginal smear.Sex hormones and morphology of the ovary,oviduct,and uterus were observed.Expressions and intensity of androgen receptor and tyrosine phosphorylated proteins of reproductive organs were investigated by Western blot.Results:Various polycysts and increased androgen receptor expression were present in the ovary of the PCOS group.The levels of follicle-stimulating hormone and testosteone were significantly higher in the PCOS group while progesterone and estradiol levels were significantly decreased as compared with the control group(P<0.05).Only the size of uterus in the PCOS group was significantly smaller than the control group.However,the density of collagen fibers observed in PCOS uterus was greater than the control group.Moreover,tyrosine phosphorylated proteins were significantly overexpressed in ovary(52,42,and 28 kDa),oviduct(72,56,42,and 28 kDa),and uterus(53 and 42 kDa)of the PCOS group compared to the control group.Conclusions:Presence of tyrosine phosphorylated proteins in the ovary,oviduct and uterus suggests that overexpression of tyrosine phosphorylated proteins may be involved in potential mechanism of female infertility especially in PCOS.
文摘At 8 weeks after intragastric administration of icariin to senescence-accelerated mice (P8 strain), Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse.
基金Supported by National Natural Science Foundation of China(81673856,81573865)China Postdoctoral Science Foundation(2016M592319,2017T100542)+1 种基金Youth Project of Hubei University of Traditional Chinese Medicine(Zhong Yi Xiao Zi2015182)PhD Research Foundation of Hubei University of Traditional Chinese Medicine(Zhong Yi Dang Zi201425)
文摘[Objectives] To study the effects and mechanism of notoginsenoside Rg1 on the spatial learning and memory and phosphorylated tau protein in the AD( Alzheimer's Disease) model rat. [Methods]The AD model rat was replicated by injection of Aβ_(25-35) in the left lateral ventricles of SD rats. The low dose( 25 mg/kg),middle dose( 50 mg/kg) and high dose( 100 mg/kg) notoginsenoside Rg1 was used for intragastric administration,respectively,two times every day. After 4 weeks,the Morris water maze test was done to detect the learning and memory capacity,and the immunoblotting,immunohistochemical methods were used to detect the changes in the phosphorylation level and distribution of tau protein in hippocampus of the rats. [Results] After the intracerebroventricular injection of Aβ_(25-35),the learning and memory capacity of the model rats was significantly lower than the learning and memory capacity of the normal control rats. The immunoblotting test results showed that the phosphorylation level of tau protein threonine 231 site( Thr231) in hippocampus was significantly increased,and the nonphosphorylation level was significantly decreased. The morphological testing results showed that the phosphorylation level of tau protein Thr231 of AD model rats was increased markedly in region of DG,CA1 and CA3 of the hippocampus. The intervention of the middle dose notoginsenoside Rg1 could significantly improve the learning and memory capacity of the model rats in Morris water maze. The notoginsenoside Rg1 in three different doses could all reduce the phosphorylation level of tau protein Thr231 in the hippocampal DG,CA1,CA3 regions,and there were no significant differences among the three doses. [Conclusions]The notoginsenoside Rg1 could improve Aβ_(25-35)-induced spatial learning and memory impairment of the AD model rats,and decreased the phosphorylation level of tau protein in hippocampus.
基金supported by the National High Technology Research and Development Program of China(863 Program),No.2012AA020905the Biological Industry Development Funds of Shenzhen,No.JC201005260093A+1 种基金the National Natural Science Foundation of China/Research Grants Council Joint Research Scheme,No.81161160570the National Natural Science Foundation of China,No.81171143the Tsinghua-Yue-Yuen Medical Sciences Fund
文摘Transient brain ischemia has been shown to induce hyperphosphorylation of the micro- tubule-associated protein tau. To further determine the mechanisms underlying these processes, we investigated the interaction between tau, glycogen synthase kinase (GSK)-313 and protein phos- phatase 2A. The results confirmed that tau protein was dephosphorylated during brain ischemia; in addition, the activity of GSK-3β was increased and the activity of protein phosphatase 2A was de- creased. After reperfusion, tau protein was hyperphosphorylated, the activity of GSK-3β was de- creased and the activity of protein phosphatase 2A remained low. Importantly, the interaction of tau with GSK-3β and protein phosphatase 2A was altered during ischemia and reperfusion. Lithium chloride could affect tau phosphorylation by regulating the interaction of tau with GSK-3β and pro- tein phosphatase 2A, and improve learning and memory ability of rats after transient brain ischemia. The present study demonstrated that it was the interaction of tau with GSK-3β and protein phos- phatase 2A, rather than their individual activities, that dominates the phosphorylation of tau in tran- sient brain ischemia. Hyperphosphorylated tau protein may play an important role in the evolution of brain injury in ischemic stroke. The neuroprotective effects of lithium chloride partly depend on the inhibition of tau phosphorylation during transient brain ischemia.
文摘BACKGROUND: The differential diagnosis of many neurodegenerative disorders depends primarily on clinical symptoms together with imaging methods. Recently, increased importance has been placed on the use of biomarkers for diagnosing various neurodegenerative disorders. OBJECTIVE: To assess the feasibility of tau-protein, phosphorylated tau-protein, beta-amyloid 42 (Aβ42), and 14-3-3 protein as biomarkers for diagnosing several neurodegenerative diseases complicated by cognitive deficits. DESIGN, TIME AND SETTING: A non-randomized, concurrent, case-control investigation was performed in three medical centers in the Czech Republic (Department of Neurology at the University Hospital in Hradec Kralove, Department of Neurology at the 2rd Medical Faculty, and the University Hospital Motol) between October 2000 and November 2006. PARTICIPANTS: Eighteen patients with probable AIzheimer's disease, 4 patients with Creutzfeldt-Jakob disease, 10 patients with frontotemporal dementia, 9 patients with clinically isolated syndrome suggestive of multiple sclerosis, and 7 patients with multiple sclerosis, as well as 38 race-, nationality-, and age-matched cognitively intact controls, were included in the study. Diagnoses were established based on the following criteria: the criteria for Alzheimer's disease proposed by the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association, WHO criteria for Creutzfeldt-Jakob disease, Neary criteria for frontotemporal dementia, and McDonald's criteria for multiple sclerosis. All included patients were confirmed to suffer from various degrees of dementia. METHODS: Enzyme-linked immunosorbent assay was used to measure concentrations of tau-protein, phosphorylated tau-protein, and Aβ42 in cerebrospinal fluid (CSF) samples collected by standard lumbar puncture from each patient. Moreover, 14-3-3 protein was assessed by Western blot in CSF of Creutzfeldt-Jakob disease patients. Cognitive status was assessed using the Mini Mental Scale Examination (MMSE) in all subjects. MAIN OUTCOME MEASURES: Establishment of biomarkers with greatest specificity and sensitivity for the investigated disorders according to Receiver Operating Characteristic curves, which were based on values from patients and controls; correlation between concentrations of given biomarkers and demographic parameters, diagnosis, duration of disease, and level of cognitive deficit. RESULTS: Increased concentrations of total tau protein and phosphorylated tau protein, and decreased levels of Aβ42, in CSF of Alzheimer's disease patients reached the required sensitivity/specificity ratio of 80% or greater. A marked elevation in CSF concentrations of total tau protein showed even greater sensitivity than 14-3-3 protein in Creutzfeldt-Jakob disease. There was no association between selected biomarkers and frontotemporal dementia or multiple sclerosis. Phosphorylated tau-protein was the only biomarker that noticeably correlated with MMSE scores for Alzheimer's disease.CONCLUSION: Levels of total tau protein, phosphorylated tau protein, and A!342 in the CSF could differentiate patients with Alzheimer's disease and Creutzfeldt-Jakob disease from healthy controls and patients with other neurodegenerative disorders. The diversity of absolute values demonstrates the necessity to establish a specific standard for each laboratory.
文摘In order to investigate ATM in mediating DNA damage signal to p53 in the cellular response to IR, kinase activities of ATM and c-Abl immunoprecipitates and its activation by IR and damaged DNA have been analyzed. Results demonstrate that deficient ATM caused failure to activate phosphorylation of many proteins in response to radiation . ATM
文摘The immunoregulatory effect of TLSFJM on the expression of T cell IL- 2R and protein tyrosine phosphorylation ( PTP ) was investigated by immunohistochemistry technique. The results showed that TLSFJMcan markedly suppress the expression of IL-2R and PTP on PHA or TPA-stimulated human PBMC and murine IL-2 dependent cell line CTLL-2. However, there was no effect of TLSFJMon the production of IL-1, IL-2 and IL-6 that play an important role in the course of T lymphocyte proliferation and differentiation.