Identif ication of a hypersensitive response core peptide of HrpZ and its role in increasing grape downy mildew resistance

Harpins play a key role in inducing disease resistance in crops,and identifying their core functional regions and establishing a system for their efficient expression would be very valuable.In this study,large amounts of soluble fusion proteins of harpin HrpZ and its subpeptides were obtained via the optimized induction conditions(28℃ with 0.5 mmol·L^(-1) IPTG for 6 h)in Escherichia coli BL21(DE3).Hypersensitive response(HR)assays demonstrated that the C-terminal 66 aa of HrpZ(HrpZ_C_2_2)elicited a strong HR in tobacco(Nicotiana benthamiana)and grape(Flame Seedless)leaves.Additionally,treatment with HrpZ,and particularly HrpZ_C_2_2,significantly reduced the disease incidence and severity index of field vine leaves and those inoculated with downy mildew.The determination of the physiological parameters indicated that HrpZ,and especially HrpZ_C_2_2,improved the photosynthesis-and chlorophyll fluorescence-related parameters,enhanced the activity of defense-related enzymes,including SOD,POD,CAT and PAL,and increased the H_(2)O_(2) level.Collectively,we efficiently expressed a core peptide of HrpZ and elucidated its strong ability to elicit a HR and resistance to downy mildew.This research provides insight into understanding the structure and function of HrpZ and will advance the application of HrpZ_C_2_2 to increase the resistance of grapevine to downy mildew.

A Selective‑Response Hypersensitive Bio‑Inspired Strain Sensor Enabled by Hysteresis Effect and Parallel Through‑Slits Structures

Flexible strain sensors are promising in sensing minuscule mechanical signals,and thereby widely used in various advanced fields.However,the effective integration of hypersensitivity and highly selective response into one flexible strain sensor remains a huge challenge.Herein,inspired by the hysteresis strategy of the scorpion slit receptor,a bio-inspired flexible strain sensor(BFSS)with parallel through-slit arrays is designed and fabricated.Specifically,BFSS consists of conductive monolayer graphene and viscoelastic styrene–isoprene–styrene block copolymer.Under the synergistic effect of the bio-inspired slit structures and flexible viscoelastic materials,BFSS can achieve both hypersensitivity and highly selective frequency response.Remarkably,the BFSS exhibits a high gage factor of 657.36,and a precise identification of vibration frequencies at a resolution of 0.2 Hz through undergoing different morphological changes to high-frequency vibration and low-frequency vibration.Moreover,the BFSS possesses a wide frequency detection range(103 Hz)and stable durability(1000 cycles).It can sense and recognize vibration signals with different characteristics,including the frequency,amplitude,and waveform.This work,which turns the hysteresis effect into a"treasure,"can provide new design ideas for sensors for potential applications including human–computer interaction and health monitoring of mechanical equipment.

Early cardiopulmonary resuscitation on serum levels of myeloperoxidase,soluble ST2,and hypersensitive C-reactive protein in acute myocardial infarction patients

BACKGROUND Prompt and effective cardiopulmonary resuscitation(CPR)can promote the recovery of spontaneous circulation to some extent and can save patients’lives.The minimum target of cardiac resuscitation is the restoration of spontaneous circulation(ROSC).However,owing to prolonged sudden cardiac arrest,there is relatively high mortality within 24 h after cardiac resuscitation.Moreover,severe cerebral anoxia can deteriorate the prognosis of patients.Therefore,it is important to adopt an effective clinical evaluation of acute myocardial infarct(AMI)patients’prognosis after cardiac resuscitation for the purpose of prevention and management.AIM To investigate early CPR effects on human myeloperoxidase(MPO),soluble ST2(sST2),and hypersensitive C-reactive protein(hs-CRP)levels in AMI patients.METHODS In total,54 patients with cardiac arrest caused by AMI in our hospital were selected as the observation group,and 50 other patients with AMI were selected as the control group.The differences in serum levels of MPO,sST2,and hs-CRP between the observation group and the control group were tested,and the differences in the serum levels of MPO,sST2,and hs-CRP in ROSC and non-ROSC patients,and in patients who died and in those who survived,were analyzed.RESULTS Serum levels of MPO,sST2,hs-CRP,lactic acid,creatine kinase isoenzyme(CKMB),and cardiac troponin I(cTnI)were significantly higher in the observation group than in the control group(P<0.05).Serum levels of MPO,sST2,hs-CRP,lactic acid,CK-MB,and cTnI in the observation group were lower after CPR than before CPR(P<0.05).In the observation group,MPO,sST2,hs-CRP,lactic acid,CK-MB,and cTnI serum levels were lower in ROSC patients than in non-ROSC patients(P<0.05).MPO,sST2,hs-CRP,and lactic acid serum levels of patients who died in the observation group were higher than those of patients who survived(P<0.05).The areas under receiver operating characteristic curve predicted by MPO,sST2,hs-CRP,lactic acid,CK-MB,and cTnI were 0.616,0.681,0.705,0.704,0.702,and 0.656,respectively(P<0.05).The areas under receiver operating characteristic curve for MPO,SST2,hs-CRP,and lactic acid to predict death were 0.724,0.800,0.689,and 0.691,respectively(P<0.05).Logistic regression analysis showed that MPO,sST2,and hs-CRP were the influencing factors of ROSC[odds ratios=1.667,1.589,and 1.409,P<0.05],while MPO,sST2,hs-CRP,and lactic acid were the influencing factors of death(odds ratios=1.624,1.525,1.451,and 1.365,P<0.05).CONCLUSION Serum levels of MPO,sST2,hs-CRP,and lactic acid have a certain value in predicting recovery and prognosis of patients with ROSC.

Alpha-picolinic acid,a fungal toxin and mammal apoptosis-inducing agent,elicits hypersensitive-like response and enhances disease resistance in rice

Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.

Effects of Microtubule Polymerization Inhibitor on the Hypersensitive Response of Wheat Induced by the Non-Host Pathogen Sphaerotheca fuliginea

The plant cytoskeleton is a highly dynamic and versatile intracellular scaffold composed of microtubules and microfilaments, serving a multiplicity of functions in plant cells. To reveal the relationship between the cytoskeleton in wheat （Triticum aestivum L.） cv. Suwon 11 attacked by the non-host pathogen Sphaerotheca fuliginea and the initiation of the hypersensitive response, the microtubule inhibitor oryzalin was injected into the wheat leaves immediately prior to inoculation. The incidence of hypersensitive cell death was significantly lower than that in water-treated control. In addition, the occurrence of hypersensitive cell death was also delayed and S. fuliginea was able to penetrate and form haustoria in epidermal tissues of wheat. All the results above indicated that hypersensitive cell death was associated with depolymerisation of microtubules, suggesting that microtubules might play an important role in the expression of non-host resistance of wheat.

Exchangeability of Two hrp Gene Fragments from Xanthomonas oryzae pv.oryzae and pv.oryzicola for Hypersensitive Response on Tobacco and Pathogenicity on Rice

hrp mutants were produced from strain JXOIII of Xanthomonas oryzae pv. oryzae (Xoo) and strain RS105 of X.o. pv. oryzicola (Xooc), respectively, by using diethyl sulfate (DES) as a mutagenic che mical. All the hrp mutants lost their pathogenicity on a susceptible host plant, rice (Shanyou63), and elicitation of the hypersensitive response (HR) on a nonhost plant, tobacco (NC89). Extracellular enzyme (amy lase, pectate lyase, proteinase, cellulase and lipase) activities of all the hrp mutants were similar to those of the corresponding wild type strains. The response of tobacco to cell sonicated integrations of the wild type strains and the hrp mutants demonstrated that there existed an HR eliciting substance which was heat stable and sensitive to protease. No HR appeared on tobacco after infiltration of the lipopolysaccharide (LPS) of both the wild strains and hrp mutants into tobacco leaves. The ability of the Xooc hrp mutants to induce HR on tobacco and cause streak disease on rice was restored by complementation with pUHRX245 from JXOIII genomic DNA library and by pUHRS138 from RS105 genomic DNA library, respectively. Subcloning of a 38.6 kb hrp fragment insert in pUHRX245 and a 39.3 kb insert in pUHRS138 revealed that a 3.3 kb Sac Ⅰ fragment from pUHRX245 and a 4.5 kb Bam HⅠ Kpn Ⅰ fragment from pUHRS138 were the minimal functional portions required for restoration of the ability of Xooc hrp mutants to induce HR on tobacco and cause disease on rice. The disease symptom caused by the conjugant (M1005 plus 3.3 kb) on rice was similar to that caused by the wild type of Xooc. It suggests that the two fragments contain the same hrp gene(s) and are responsible reciprocally for HR induction on tobacco and pathogenicity on rice.

Induction of Hypersensitive Response and Nonhost Resistance by a Cladosporium fulvum Elicitor CfHNNI1 is Dose-Dependent and Negatively Regulated by Salicylic Acid

Nonhost resistance is a phenomenon that enables plants to protect themselves against the majority of potential pathogens, and thus has a great potential for application in plant protection. We recently found that CfHNNI1 （for Cladosporium fulvum host and nonhost plant necrosis inducer 1） is an inducer of plant hypersensitive response （HR） and nonhost resistance. In this study, its functional mechanism was analyzed. CfHNN11 was a single copy gene in C. fulvum genome. The functional ORF of the CfHNN11 cDNA was ATG3-TAG780, which showed homology with genes encoding bZIP transcription factors. The functional ORF included in frame an inner one ATG273-TAG780, which was sufficient to induce HR in plants. CfIINN11 induced plant HR in a dose-dependent manner. CfHNNIl-induced necrosis in NahG transgenic tomato plants was significantly stronger than that in their wild type controls. However, the necrosis in Nr and defl tomato mutants was similar to that in their corresponding wild type plants. These data demonstrate that induction of HR and nonhost resistance by CfHNNI1 is negatively regulated by salicylic acid signalling pathway but independent of ethylene and jasmonic acid signalling pathways.

Disruption of non-classically secreted protein(MoMtp)compromised conidiation,stress homeostasis,and pathogenesis of Magnaporthe oryzae

Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.

OsbZIP53 Negatively Regulates Immunity Response by Involving in Reactive Oxygen Species and Salicylic Acid Metabolism in Rice

The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants.To further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRISPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic plants.Comprehensive analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid pathway.Specifically,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting OsMYBS1.In addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.

Structural and Functional Insights into an Arabidopsis NBS-LRR Receptor in Nicotiana benthamiana

Nucleotide-binding site leucine-rich repeat receptors (NBS-LRR/NLRs) are crucial intracellular immune proteins in plants. Previous article reported a novel NLR protein SUT1 (SUPPRESSORS OF TOPP4-1, 1), which is involved in autoimmunity initiated by type one protein phosphatase 4 mutation (topp4-1) in Arabidopsis, however, its role in planta is still unclear. This study employed Nicotiana benthamiana, a model platform, to conduct an overall structural and functional analysis of SUT1 protein. The transient expression results revealed that SUT1 is a typical CNL (CC-NBS-LRR) receptor, both fluorescence data and biochemical results showed the protein is mainly anchored on the plasma membrane due to its N-terminal acylation site. Further truncation experiments announced that its CC (coiled-coil) domain possessed cell-death-inducing activity. The outcomes of point mutations analysis revealed that not only the CC domain, but also the full-length SUT1 protein, whose function and subcellular localization are influenced by highly conserved hydrophobic residues. These research outcomes provided favorable clues for elucidating the activation mechanism of SUT1.

Hypersensitive syndrome reaction of antiepileptic drug: two case reports and literature review

Hypersensitivity syndrome reaction of antiepileptic drug （AED） can induce serious cutaneous, hematological and hepatic events. In severe cases, fulminant hepatic failure may necessitate liver transplantation, and most patients die due to the liver failure. Severe adverse cutaneous reactions, including Steven-Johnson syndrome （SJS）, toxic epidermal necrolysis （TEN） and hypersensitivity syndrome, are rare but life-threatening. Its morality rate is as high as 5%-50%. Accurate early diagnosis and timely treatment may contribute to decreased morality rate. In this paper, we reported cases of hypersensitive syndrome reaction to carbamazepine （CBZ） or phenobarbital （PB） in two patients with epilepsy. Clarification of the therapeutic process and the early manifestation of epilepsy may be helpful to improve the epilepsy therapy while avoiding the potential severe adverse cutaneous reactions of AED. The two reported cases highlighted that the therapeutic process of CBZ and PB might lead to the fatal allergic reaction, which was mainly caused by the absence of epoxide-hydroxylase and the defect of hepatocytes.

Genetic diversity of Harpins from Xanthomonas oryzae and their activity to induce hypersensitive response and disease resistance in tobacco

Three hrfA (hypersensitive response-functioning faction A) homologues (hrf1, hrf2 and hrf3) are cloned from 12 strains of Xanthomonas oryzae using PCR based techniques. Hrf1, hrf2 and hrf3 are derived from strains belonging to X. o. pv. oryzae, X. o. pv. oryzicola and X. o. pv. oryzae respectively. Sequence analysis shows that all three genes encode glycine-rich pro-teins with various numbers of GGG-GG motifs. They all share a conserved cysteine residue at position 45 or 47. Hrf1 and hrf3 encode HarpinXoo while hrf2 encodes Harpinxooc. Hrf1 and hrf3 encodes two different types of HarpinXoo proteins. Hrf1 from X. o. pv. oryzae strains ( JxoIII, JxoIV, Jxov, Pxo61, Pxo76, Pxo79, Pxo99, Pxo99 and Pxo124) encodes a 15.6 kD HarpinXoo with 3 GGG-GG motifs while Hrf3 from strain Pxo86 and Pxo112 encodes a 15.9 kD Harpinxoo with 4 GGG-GG motifs. Harpinxooc encoded by hrf2 from X. o. pv. oryzicola (strain RS105) has the mo-lecular weight of 15.3 kD and contains 2 GGG-GG motifs. Cluster analysis is performed using deduced sequences of hrf1, hrf2 and hrf3 as well as previously reported Hpa1 and XopI protein sequence. The results indicated that Harpinxoo and Harpinxooc belong to two closely related sub-groups. Hrf, hrf2 and hrf3 are expressed in E. coli strain BL21 successfully. Under the same condition, hrf1, hrf2 and hrf3 are expressed at the level of 0.389, 0.530 and 0.083 mg/mL re-spectively. All expressed hrf1, hrf2 and hrf3 proteins (Harpins) are shown to be able to induce hypersensitive reaction and TMV resistance on tobacco. Among the three proteins, Hrf2 has the highest activity while Hrf3 has the lowest activity.

Relationship among soluble CD105, hypersensitive C-reactive protein and coronary plaque morphology： an intravascular ultrasound study

Background Rupture of unstable plaque with subsequent thrombus formation is the common pathophysiological substrate of acute coronary syndrome （ACS）. It is of potential significance to explore the blood indexes predicting plaque characteristics. We investigated the relationship among soluble CD105, hypersensitive C-reactive protein （hs-CRP）, and coronary plaque morphology.Methods A clinical study from April 2004 to December 2006 was conducted in 130 patients who were divided into 3 groups： 56 patients （43.1%） in stable angina （SA） group, 52 patients （40.0%） in unstable angina （UA） group and 22 patients （16.9%） in acute myocardial infarction group. The concentrations of soluble CD105 and hs-CRP were measured in all of the patients by cardioangiography （CAG）. Plasma samples of arterial blood were collected prior to the procedure. The levels of soluble CD105 and hs-CRP were measured by enzyme-linked immunosorbent assay （ELISA）.Results Unstable and ruptured plaque was found more frequently in patients with acute myocardial infarction and UA. External elastic membrane cross-sectional area （EEM CSA）, plaque area, lipid pool area and plaque burden were significantly larger in the ruptured and unstable plaque group. Positive remodeling, thinner fabric-cap, smaller minimal lumen cross-sectional area （MLA）, dissection and thrombus were significantly more frequent in the ruptured and unstable plaque group. Remodeling index （RI） was positively correlated with the levels of soluble CD105 in the UA group （r=0.628, P〈0.01） and the acute myocardial infarction group （r=0.639, P〈0.01）. The levels of soluble CD105 and hs-CRP were higher in the ruptured plaque group. Soluble CD105 〉4.3 ng/ml was used to predict ruptured plaque with a receiver operating characteristic （ROC） curve area of 0.77 （95% confidence interval （CI）, 66.8%-87.2%）, a sensitivity of 72.8%, a specificity of 78.0% and an accuracy of 70.2% （P〈0.01）, similarly for hs-CRP 〉 5.0 mg/ml with a ROC curve area of 0.70 （95% CI, 59.2%-80.2%）, a sensitivity of 70.2%, a specificity of 76.2% and an accuracy of 67.2% （P〈0.01）.Conclusions The plaque characteristics correlate with the clinical presentation. The elevation of soluble CD105 and hs-CRP is related to the plaque instability and rupture.

Identification of Regulatory DNA Elements Using Genome-wide Mapping of DNase I Hypersensitive Sites during Tomato Fruit Development

Development and ripening of tomato fruit are precisely controlled by transcriptional regulation, which de- pends on the orchestrated accessibility of regulatory proteins to promoters and other c/s-regulatory DNA elements. This accessibility and its effect on gene expression play a major role in defining the develop- mental process. To understand the regulatory mechanism and functional elements modulating morpholog- ical and anatomical changes during fruit development, we generated genome-wide high-resolution maps of DNase I hypersensitive sites （DHSs） from the fruit tissues of the tomato cultivar ＂Moneymaker＂ at 20 days post anthesis as well as break stage. By exploring variation of DHSs across fruit development stages, we pinpointed the most likely hypersensitive sites related to development-specific genes. By detecting binding motifs on DHSs of these development-specific genes or genes in the ascorbic acid biosynthetic pathway, we revealed the common regulatory elements contributing to coordinating gene transcription of plant ripening and specialized metabolic pathways. Our results contribute to a better understanding of the regulatory dynamics of genes involved in tomato fruit development and ripening.

Efficient two-photon sensitized luminescence of europium (Ⅲ) complex based on hypersensitive transitions

Red frequency-upconversion fluorescence emission is observed in europium（Ⅲ） complex with encapsulating polybenzimidazole tripodal ligands, pumped with 930- and 1070-nm picosecond laser pulses. The lumines- cence of transition 5D0 →7F2 （612 nm） is induced by two-photon absorption of hypersensitive transitions 7F0 →5D2 （465 nm） and 7F1 →5D1 （535 nm）. Analysis results suggest that the two-photon excitation strength of these hypersensitive transitions is increased dramatically owing to the C3 symmetry of the coordination field.

Investigation of the cell composition and gene expression in the delayed-type hypersensitivity tuberculin skin test

Dear Editor,The tuberculin skin test(TST)reagents have continuously improved,with the ESAT6-CFP10(EC)test having recently been introduced,but are seldom based on the direction of the delayed-type hypersensitivity(DTH)mechanism.Previous studies only partially showed the infiltration and activation of immune cells and the production of cytokines of the skin induration[1,2],and lack the detailed measurements of cell proportions and gene expression in the DTH response.Therefore,in this study,we revealed the comprehensive characteristics of DTH by single-cell RNA sequencing(scRNA-seq)in the guinea pig tuberculosis(TB)model[Experimental Animal Welfare Ethics Committee,Beijing Tuberculosis and Thoracic Tumor Research Institute(2021-064)].

Serotonin receptor 2B induces visceral hyperalgesia in rat model and patients with diarrhea-predominant irritable bowel syndrome

BACKGROUND Serotonin receptor 2B(5-HT2B receptor)plays a critical role in many chronic pain conditions.The possible involvement of the 5-HT2B receptor in the altered gut sensation of irritable bowel syndrome with diarrhea(IBS-D)was investigated in the present study.AIM To investigate the possible involvement of 5-HT2B receptor in the altered gut sensation in rat model and patients with IBS-D.METHODS Rectosigmoid biopsies were collected from 18 patients with IBS-D and 10 patients with irritable bowel syndrome with constipation who fulfilled the Rome IV criteria and 15 healthy controls.The expression level of the 5-HT2B receptor in colon tissue was measured using an enzyme-linked immunosorbent assay and correlated with abdominal pain scores.The IBS-D rat model was induced by intracolonic instillation of acetic acid and wrap restraint.Alterations in visceral sensitivity and 5-HT2B receptor and transient receptor potential vanilloid type 1(TRPV1)expression were examined following 5-HT2B receptor antagonist adminis-tration.Changes in visceral sensitivity after administration of the TRPV1 antago-INTRODUCTION Irritable bowel syndrome(IBS)is a chronic functional bowel disorder characterized by recurrent abdominal pain with altered bowel habits that affects approximately 15%of the population worldwide[1].IBS significantly impacts the quality of life of patients.Although the pathogenesis of IBS is not completely understood,the role of abnormal visceral sensitivity in IBS has recently emerged[2,3].5-Hydroxytryptamine(5-HT)is known to play a key role in the physiological states of the gastrointestinal tract.Plasma 5-HT levels in IBS with diarrhea(IBS-D)patients were greater than those in healthy controls[4],suggesting a possible role of 5-HT in the pathogenesis of IBS-D.The serotonin receptor 2(5-HT2 receptor)family comprises three subtypes:5-HT2A,5-HT2B,and 5-HT2c.All 5-HT2 receptors exhibit 46%-50%overall sequence identity,and all of these receptors preferentially bind to Gq/11 to increase inositol phosphates and intracellular calcium mobilization[5].5-HT2B receptors are widely expressed throughout the gut,and experimental evidence suggests that the primary function of 5-HT2B receptors is to mediate contractile responses to 5-HT through its action on smooth muscle[6].The 5-HT2B receptor is localized to both neurons of the myenteric nerve plexus and smooth muscle in the human colon.The 5-HT2B receptor mediates 5-HT-evoked contraction of longitudinal smooth muscle[6].These findings suggest that the 5-HT2B receptor could play an important role in modulating colonic motility,which could affect sensory signaling in the gut.Other laboratories have shown that the 5-HT2B receptor participates in the development of mechanical and formalin-induced hyperalgesia[7,8].A 5-HT2B receptor antagonist reduced 2,4,6-trinitrobenzene sulfonic acid(TNBS)and stress-induced visceral hyperalgesia in rats[9,10].However,the role of the 5-HT2B receptor in IBS-D patients and in acetic acid-and wrap restraint-induced IBS-D rat models was not investigated.

Interactions between GATA transcription factors and the DNasel hypersensitive sites in the human p-globin gene LCR

In this study, we analyze the binding of nuclear proteins isolated from the hydroxyurea (Hu)-induced and uninduced HEL cells to the DNasel hypersensitive sites Ⅲ (HS3 -14991 --14716 bp) and Ⅳ(HS4 -18586-18306 bp) in the human p-globin gene locus control region (LCR). Using Western blot assay, we demonstrate that GATA-1 transcription factor in HEL cells is increased following the induction of Hu, while GATA-2 transcription factor is decreased. Based on both the competition EMSA and the Western blot assay, our data reveal that the nuclear protein isolated from the uninduced HEL cells, which can bind to the HS3 and HS4 core DNA sequences, is mainly GATA-2; however, the nuclear proteins isolated from the Hu-induced HEL cells, which can bind to the HS3 and HS4 core DNA sequences, are mainly GATA-1 and GATA-X (a kind of unknown GATA factor). These results suggest that the erythroid specific transcription factors (GATA-1 and GATA-2) in the Hu-induced and uninduced HEL cells can selectively bind to the HS3

Two amino acids on 2a polymerase of Cucumber mosaic virus co-determine hypersensitive response on legumes

The hypersensitive response (HR) is one of the most important defense responses during the incompatible interaction between plant and pathogen. The viral determinant of HR on legumes induced by Cucumber mosaic virus (CMV) was studied, and our previous results showed that 243 nucleotides on 2a polymerase gene of CMV were involved in the induction of HR on leg-umes. With further analysis of the nucleotides and amino acids in this region, the amino acids Phe and Ala at positions 631 and 641 in the 2a polymerase of CMV-Fny, a legume local necrotic strain, were specifically exchanged to Tyr and Ser, respectively and simultaneously, in the 2a polymerase of CMV-P1, a legume systemic infecting strain, and three point mutants were constructed. The point mutant Fny-F/Y (Phe631 to Tyr) induced large necrotic lesions instead of pinpoint lesions, and the size of lesions could enlarge from initial sites. The point mutant Fny-A/S (Ala641 to Ser) induced similar symptoms as CMV-Fny. The double-point mutant Fny-FA/YS (Phe631 to Tyr and Ala641 to Ser) infected the legumes systemically without HR. These data indicate that the induc-tion of HR on legumes is co-determined by two amino acids at positions 631 and 641 in CMV 2a polymerase.

Interactions between HMG proteins and the core sequence of DNaseI hypersensitive site 2 in the locus control region (LCR) of the human β-Mike globin gene cluster

HMG proteins are abundant chromosomal non-histone proteins. It has been suggested that the HMG proteins may play an important role in the structure and function of chromatin. In the present study, the binding of HMG proteins (HMG1/2 and HMG14/17) to the core DNA sequence of DNasel hypersensitive site 2 (HS2core DNA sequence, -10681-10970 bp) in the locus control region (LCR) of the human β-like globin gene cluster has been examined by using both the in vitro nucleosome reconstitution and the gel mobility shift assays. Here we show that HMG1/2 can bind to the naked HS2core DNA sequence, however, HMG 14/17 cannot. Using the in vitro nucleosome reconstitution we demonstrate that HMG14/17 can bind to the HS2core DNA sequence which is assembled into nucleosomes with the core histone octamer transferred from chicken erythrocytes. In contrast, HMG 1/2 cannot bind to the nucleosomes reconstituted in vitro with the HS2core DNA sequence. These results indicate that the binding patterns between HMG proteins and the HS2core DNA sequence which exists in different states (the naked DNA or the in vitro reconstituted nucleosomal DNA) are quite different. We speculate that HMG proteins might play a critical role in the regulation of the human β-like globin gene's expression.