The 18 species of bird studied originally are known to belong to muscicapids, robins and sylviids of passerines, but some dis- putations are always present in their classification systems. In this experiment, phylogen...The 18 species of bird studied originally are known to belong to muscicapids, robins and sylviids of passerines, but some dis- putations are always present in their classification systems. In this experiment, phylogenetic relationships of 18 species of passerines were studied using Adenylate Kinase lntron 5 （AKS） sequences and DNA techniques. Through sequences analysis in comparison with each other, phylogenetic tree figures of 18 species of passerines were constructed using Neighbor-Joining （N J） and Maximum-Parsimony （MP） meth- ods . The results showed that sylviids should be listed as an independent family, while robins and flycatchers should be listed into Musci- capidae. Since the phylogenetic relationships between long-tailed tits and old world warblers are closer than that between long-tailed tits and parids, the long-tailed tits should be independent of paridae and be categorized into aegithalidae. Muscicapidae and Paridae are known to be two monophylitic families, but Sylviidae is not a monophyletic group. AK5 sequences had better efficacy in resolving close relationships of interspecies among intrageneric groups.展开更多
BACKGROUND Spermatogonial stem cells(SSCs)are the origin of male spermatogenesis,which can reconstruct germ cell lineage in mice.However,the application of SSCs for male fertility restoration is hindered due to the un...BACKGROUND Spermatogonial stem cells(SSCs)are the origin of male spermatogenesis,which can reconstruct germ cell lineage in mice.However,the application of SSCs for male fertility restoration is hindered due to the unclear mechanisms of proliferation and self-renewal in humans.AIM To investigate the role and mechanism of SPOC domain-containing protein 1(SPOCD1)in human SSC proliferation.METHODS We analyzed publicly available human testis single-cell RNA sequencing(RNAseq)data and found that SPOCD1 is predominantly expressed in SSCs in the early developmental stages.Small interfering RNA was applied to suppress SPOCD1 expression to detect the impacts of SPOCD1 inhibition on SSC proliferation and apoptosis.Subsequently,we explored the target genes of SPOCD1 using RNA-seq and confirmed their role by restoring the expression of the target genes.In addition,we examined SPOCD1 expression in some non-obstructive azoospermia(NOA)patients to explore the correlation between SPOCD1 and NOA.RESULTS The uniform manifold approximation and projection clustering and pseudotime analysis showed that SPOCD1 was highly expressed in the early stages of SSC,and immunohistological results showed that SPOCD1 was mainly localized in glial cell line-derived neurotrophic factor family receptor alpha-1 positive SSCs.SPOCD1 knockdown significantly inhibited cell proliferation and promoted apoptosis.RNA-seq results showed that SPOCD1 knockdown significantly downregulated genes such as adenylate kinase 4(AK4).Overexpression of AK4 in SPOCD1 knockdown cells partially reversed the phenotypic changes,indicating that AK4 is a functional target gene of SPOCD1.In addition,we found a significant downregulation of SPOCD1 expression in some NOA patients,suggesting that the downregulation of SPOCD1 may be relevant for NOA.CONCLUSION Our study broadens the understanding of human SSC fate determination and may offer new theories on the etiology of male infertility.展开更多
Activation and aggregation of blood platelets is crucial for hemostasis and thrombosis. In the vascular system adenine nucleotides are important signaling molecules playing a key role in hemostasis. ADP was the first ...Activation and aggregation of blood platelets is crucial for hemostasis and thrombosis. In the vascular system adenine nucleotides are important signaling molecules playing a key role in hemostasis. ADP was the first low molecular weight agent recognized to cause blood platelets activation and aggregation. NTPDases and adenylate kinase (AK) are the main enzymes involved in metabolism of extracellular adenine nucleotides. The majority of studies concentrated on the role of NTPDase1 (apyrase) in the inhibition of platelets aggregation. Up to now, there are still insufficient data concerning the role of AK in this process. We found that adenylate kinase activity in the serum of patients with myocardial infarction is significantly increased when compared to the healthy volunteers. The elevated activity of AK is connected to appearance of another isoform of that enzyme, expressed in patients with myocardial infarction. The influence of AK on the pig blood platelets aggregation induced by 20 μM ADP or 7.5 μg/ml rat collagen was examined. 1U of adenylate kinase added to platelet-rich plasma (PRP) before ADP or collagen, inhibited the platelets aggregation. One minute after induction of platelets activation by ADP as much as 5U of adenylate kinase was necessary to stop the platelet aggregation. In the case of collagen activated aggregation, only 2U of AK added 1 or 5 minutes after initiation of the aggregation process were sufficient for disaggregation of platelets. The increase of ATP: ADP ratio is probably responsible for the initiation of disaggregation process. We conclude that adenylate kinase is involved in regulation of plate-lets aggregation. Anticoagulative role of AK indicates the possibility of using this enzyme in the treatment of cardiovascular diseases.展开更多
The complexities of energy transfer mechanisms in the flagella of mammalian sperm flagella have been intensively investigated and demonstrate significant diversity across species.Enzymatic shuttles,particularly adenyl...The complexities of energy transfer mechanisms in the flagella of mammalian sperm flagella have been intensively investigated and demonstrate significant diversity across species.Enzymatic shuttles,particularly adenylate kinase(AK)and creatine kinase(CK),are pivotal in the efficient transfer of intracellular ATP,showing distinct tissue-and species-specificity.Here,the expression profiles of AK and CK were investigated in mice and found to fall into four subgroups,of which Subgroup III AKs were observed to be unique to the male reproductive system and conserved across chordates.Both AK8 and AK9 were found to be indispensable to male reproduction after analysis of an infertile male cohort.Knockout mouse models showed that AK8 and AK9 were central to promoting sperm motility.Immunoprecipitation combined with mass spectrometry revealed that AK8 and AK9 interact with the radial spoke(RS)of the axoneme.Examination of various human and mouse sperm samples with substructural damage,including the presence of multiple RS subunits,showed that the head of radial spoke 3 acts as an adapter for AK9 in the flagellar axoneme.Using an ATP probe together with metabolomic analysis,it was found that AK8 and AK9 cooperatively regulated ATP transfer in the axoneme,and were concentrated at sites associated with energy consumption in the flagellum.These findings indicate a novel function for RS beyond its structural role,namely,the regulation of ATP transfer.In conclusion,the results expand the functional spectrum of AK proteins and suggest a fresh model regarding ATP transfer within mammalian flagella.展开更多
Corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex, can be cumula- tively toxic to hippocampal neurons, the cause of which is not known. The present study determined whether the cytoso...Corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex, can be cumula- tively toxic to hippocampal neurons, the cause of which is not known. The present study determined whether the cytosol adenylate kinase （AK） system long-term exposure to high corticosterone levels. We was involved in the neuronal damage induced by nvestigated the effects of long-term exposure to high corticosterone levels on AK1 activity, AK1 mRNA expression, and energy levels in cultured hippocampal neurons. The results show that long-term exposure to high corticosterone levels induces a reduction of the cultured hippocampal neuron viability, significantly reduces energy levels, and causes a time-dependant re- duction of the AK1 activity. These findings indicate that changes in the AK system might be the mechanism underlying neuronal damage induced by long-term exposure to high corticosterone levels.展开更多
The activation and inactivation of adenylate kinase during denaturation in urea are compared with changes in UV absorbance at 287 nm, CD spectrum change at 222 nm, fluorescence intensity of ANS binding and small angle...The activation and inactivation of adenylate kinase during denaturation in urea are compared with changes in UV absorbance at 287 nm, CD spectrum change at 222 nm, fluorescence intensity of ANS binding and small angle of X ray scattering. At 1 mol/L of urea the enzyme is activated 1.5 fold companied with a subtle decreasing of its second structure, whereas its tertiary structure is fairly resistant to denaturation. By comparing the studies of the crystal structure and the mechanism of the catalysis of adenylate kinase, the activation is believed to result from the effect that low concentration of urea increases the flexibility of the active site of the enzyme. This suggestion was confirmed by the results of the fluorescence intensity changes of ANS binding to adenylate kinase versus the concentration of urea.展开更多
Six hybridoma cell lines that can continuously secrete monoclonal antibodies against adenylate kinase (AK) have been produced. The characteristics including the subclass and molecular weight of monoclonal antibodies m...Six hybridoma cell lines that can continuously secrete monoclonal antibodies against adenylate kinase (AK) have been produced. The characteristics including the subclass and molecular weight of monoclonal antibodies manufactured by these strains are also determined. Further studies show that the two monoclonal antibodies McAb3D3 and McAMD8 bind easily with AK absorbed on microtitration plates, with affinity constants of 8.4 × 108 M-1 and 9.6 × 108 M-1, while their interactions to AK in solution are much weaker, with affinity constants of 7.0 × 104 M-1 and 3.9×106M-1, respectively. Thus, McAb3D3 and McAMD8 react preferentially to the immobilized AKs. Since pro-teins are often partially denatured when absorbed on microtitration plates, it is suggested that both McAb3D3 and McAMD8 are directed against non-native AK.展开更多
Binding and releasing ligands are critical for the biological functions of many proteins,so it is important to determine these highly dynamic processes.Although there are experimental techniques to determine the struc...Binding and releasing ligands are critical for the biological functions of many proteins,so it is important to determine these highly dynamic processes.Although there are experimental techniques to determine the structure of a protein-ligand complex,it only provides a static picture of the system.With the rapid increase of computing power and improved algorithms,molecular dynamics(MD)simulations have diverse of superiority in probing the binding and release process.However,it remains a great challenge to overcome the time and length scales when the system becomes large.This work presents an enhanced sampling tool for ligand binding and release,which is based on iterative multiple independent MD simulations guided by contacts formed between the ligand and the protein.From the simulation results on adenylate kinase,we observe the process of ligand binding and release while the conventional MD simulations at the same time scale cannot.展开更多
文摘The 18 species of bird studied originally are known to belong to muscicapids, robins and sylviids of passerines, but some dis- putations are always present in their classification systems. In this experiment, phylogenetic relationships of 18 species of passerines were studied using Adenylate Kinase lntron 5 （AKS） sequences and DNA techniques. Through sequences analysis in comparison with each other, phylogenetic tree figures of 18 species of passerines were constructed using Neighbor-Joining （N J） and Maximum-Parsimony （MP） meth- ods . The results showed that sylviids should be listed as an independent family, while robins and flycatchers should be listed into Musci- capidae. Since the phylogenetic relationships between long-tailed tits and old world warblers are closer than that between long-tailed tits and parids, the long-tailed tits should be independent of paridae and be categorized into aegithalidae. Muscicapidae and Paridae are known to be two monophylitic families, but Sylviidae is not a monophyletic group. AK5 sequences had better efficacy in resolving close relationships of interspecies among intrageneric groups.
基金the National Natural Science Foundation for Young Scholars of China,No.82201771National Natural Science Foundation of China,No.32270912+2 种基金Natural Science Foundation of Changsha,No.kq2202491Research Grant of CITIC-Xiangya,No.YNXM202109 and No.YNXM202115Hunan Provincial Grant for Innovative Province Construction,No.2019SK4012。
文摘BACKGROUND Spermatogonial stem cells(SSCs)are the origin of male spermatogenesis,which can reconstruct germ cell lineage in mice.However,the application of SSCs for male fertility restoration is hindered due to the unclear mechanisms of proliferation and self-renewal in humans.AIM To investigate the role and mechanism of SPOC domain-containing protein 1(SPOCD1)in human SSC proliferation.METHODS We analyzed publicly available human testis single-cell RNA sequencing(RNAseq)data and found that SPOCD1 is predominantly expressed in SSCs in the early developmental stages.Small interfering RNA was applied to suppress SPOCD1 expression to detect the impacts of SPOCD1 inhibition on SSC proliferation and apoptosis.Subsequently,we explored the target genes of SPOCD1 using RNA-seq and confirmed their role by restoring the expression of the target genes.In addition,we examined SPOCD1 expression in some non-obstructive azoospermia(NOA)patients to explore the correlation between SPOCD1 and NOA.RESULTS The uniform manifold approximation and projection clustering and pseudotime analysis showed that SPOCD1 was highly expressed in the early stages of SSC,and immunohistological results showed that SPOCD1 was mainly localized in glial cell line-derived neurotrophic factor family receptor alpha-1 positive SSCs.SPOCD1 knockdown significantly inhibited cell proliferation and promoted apoptosis.RNA-seq results showed that SPOCD1 knockdown significantly downregulated genes such as adenylate kinase 4(AK4).Overexpression of AK4 in SPOCD1 knockdown cells partially reversed the phenotypic changes,indicating that AK4 is a functional target gene of SPOCD1.In addition,we found a significant downregulation of SPOCD1 expression in some NOA patients,suggesting that the downregulation of SPOCD1 may be relevant for NOA.CONCLUSION Our study broadens the understanding of human SSC fate determination and may offer new theories on the etiology of male infertility.
文摘Activation and aggregation of blood platelets is crucial for hemostasis and thrombosis. In the vascular system adenine nucleotides are important signaling molecules playing a key role in hemostasis. ADP was the first low molecular weight agent recognized to cause blood platelets activation and aggregation. NTPDases and adenylate kinase (AK) are the main enzymes involved in metabolism of extracellular adenine nucleotides. The majority of studies concentrated on the role of NTPDase1 (apyrase) in the inhibition of platelets aggregation. Up to now, there are still insufficient data concerning the role of AK in this process. We found that adenylate kinase activity in the serum of patients with myocardial infarction is significantly increased when compared to the healthy volunteers. The elevated activity of AK is connected to appearance of another isoform of that enzyme, expressed in patients with myocardial infarction. The influence of AK on the pig blood platelets aggregation induced by 20 μM ADP or 7.5 μg/ml rat collagen was examined. 1U of adenylate kinase added to platelet-rich plasma (PRP) before ADP or collagen, inhibited the platelets aggregation. One minute after induction of platelets activation by ADP as much as 5U of adenylate kinase was necessary to stop the platelet aggregation. In the case of collagen activated aggregation, only 2U of AK added 1 or 5 minutes after initiation of the aggregation process were sufficient for disaggregation of platelets. The increase of ATP: ADP ratio is probably responsible for the initiation of disaggregation process. We conclude that adenylate kinase is involved in regulation of plate-lets aggregation. Anticoagulative role of AK indicates the possibility of using this enzyme in the treatment of cardiovascular diseases.
基金supported by National Key Research and Development Program of China(2022YFC2702702,2021YFC2700901)the National Natural Science Foundation of China(81971441,82171607,32000584)+3 种基金the University Outstanding Young Talents Support Program(gxyq2021174)Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2019PT310002)Anhui Provincial Natural Science Foundation(2208085Y31)the Natural Science Foundation of Jiangsu Province(BK20230004).
文摘The complexities of energy transfer mechanisms in the flagella of mammalian sperm flagella have been intensively investigated and demonstrate significant diversity across species.Enzymatic shuttles,particularly adenylate kinase(AK)and creatine kinase(CK),are pivotal in the efficient transfer of intracellular ATP,showing distinct tissue-and species-specificity.Here,the expression profiles of AK and CK were investigated in mice and found to fall into four subgroups,of which Subgroup III AKs were observed to be unique to the male reproductive system and conserved across chordates.Both AK8 and AK9 were found to be indispensable to male reproduction after analysis of an infertile male cohort.Knockout mouse models showed that AK8 and AK9 were central to promoting sperm motility.Immunoprecipitation combined with mass spectrometry revealed that AK8 and AK9 interact with the radial spoke(RS)of the axoneme.Examination of various human and mouse sperm samples with substructural damage,including the presence of multiple RS subunits,showed that the head of radial spoke 3 acts as an adapter for AK9 in the flagellar axoneme.Using an ATP probe together with metabolomic analysis,it was found that AK8 and AK9 cooperatively regulated ATP transfer in the axoneme,and were concentrated at sites associated with energy consumption in the flagellum.These findings indicate a novel function for RS beyond its structural role,namely,the regulation of ATP transfer.In conclusion,the results expand the functional spectrum of AK proteins and suggest a fresh model regarding ATP transfer within mammalian flagella.
基金Supported by the National Natural Science Foundation of China (No. 90713043)the Specialized Research Fund for Doctoral Program of Higher Education of MOE, P.R.C. (No. 20060003072)+1 种基金the Key Technologies Research and Development Program of the 11th Five-Year Plan of China (No. 2006BAIO8B03-09)the Fund for Basic Research from the Nanjing University of Traditional Chinese Medicine (No. 08XJC02)
文摘Corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex, can be cumula- tively toxic to hippocampal neurons, the cause of which is not known. The present study determined whether the cytosol adenylate kinase （AK） system long-term exposure to high corticosterone levels. We was involved in the neuronal damage induced by nvestigated the effects of long-term exposure to high corticosterone levels on AK1 activity, AK1 mRNA expression, and energy levels in cultured hippocampal neurons. The results show that long-term exposure to high corticosterone levels induces a reduction of the cultured hippocampal neuron viability, significantly reduces energy levels, and causes a time-dependant re- duction of the AK1 activity. These findings indicate that changes in the AK system might be the mechanism underlying neuronal damage induced by long-term exposure to high corticosterone levels.
文摘The activation and inactivation of adenylate kinase during denaturation in urea are compared with changes in UV absorbance at 287 nm, CD spectrum change at 222 nm, fluorescence intensity of ANS binding and small angle of X ray scattering. At 1 mol/L of urea the enzyme is activated 1.5 fold companied with a subtle decreasing of its second structure, whereas its tertiary structure is fairly resistant to denaturation. By comparing the studies of the crystal structure and the mechanism of the catalysis of adenylate kinase, the activation is believed to result from the effect that low concentration of urea increases the flexibility of the active site of the enzyme. This suggestion was confirmed by the results of the fluorescence intensity changes of ANS binding to adenylate kinase versus the concentration of urea.
基金Project supported by the Climbing Project of the State Commission of Science and Technology of China.
文摘Six hybridoma cell lines that can continuously secrete monoclonal antibodies against adenylate kinase (AK) have been produced. The characteristics including the subclass and molecular weight of monoclonal antibodies manufactured by these strains are also determined. Further studies show that the two monoclonal antibodies McAb3D3 and McAMD8 bind easily with AK absorbed on microtitration plates, with affinity constants of 8.4 × 108 M-1 and 9.6 × 108 M-1, while their interactions to AK in solution are much weaker, with affinity constants of 7.0 × 104 M-1 and 3.9×106M-1, respectively. Thus, McAb3D3 and McAMD8 react preferentially to the immobilized AKs. Since pro-teins are often partially denatured when absorbed on microtitration plates, it is suggested that both McAb3D3 and McAMD8 are directed against non-native AK.
基金supported by the National Natural Science Foundation of China(No.91953101)the Strategic Priority Research Program of the Chinese Academy of Science(XDB37040202)the Hefei National Science Center Pilot Project Funds,and the New Concept Medical Research Fund of USTC。
文摘Binding and releasing ligands are critical for the biological functions of many proteins,so it is important to determine these highly dynamic processes.Although there are experimental techniques to determine the structure of a protein-ligand complex,it only provides a static picture of the system.With the rapid increase of computing power and improved algorithms,molecular dynamics(MD)simulations have diverse of superiority in probing the binding and release process.However,it remains a great challenge to overcome the time and length scales when the system becomes large.This work presents an enhanced sampling tool for ligand binding and release,which is based on iterative multiple independent MD simulations guided by contacts formed between the ligand and the protein.From the simulation results on adenylate kinase,we observe the process of ligand binding and release while the conventional MD simulations at the same time scale cannot.
