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Wang SY, Xia ZX, Yang SW, Chen WK, Zhao YL, Li MD, Tian D, Pan Y, Lin XS, Zhu XQ, Huang Z, Liu JM, Lai ZM, Tao WC, Shen ZC. Regulation of depressive-like behaviours by palmitoylation: Role of AKAP150 in the basolateral amygdala. Br J Pharmacol 2024. [PMID: 38413375 DOI: 10.1111/bph.16318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/20/2023] [Accepted: 12/23/2023] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND AND PURPOSE Protein palmitoylation is involved in learning and memory, and in emotional disorders. Yet, the underlying mechanisms in these processes remain unclear. Herein, we describe that A-kinase anchoring protein 150 (AKAP150) is essential and sufficient for depressive-like behaviours in mice via a palmitoylation-dependent mechanism. EXPERIMENTAL APPROACH Depressive-like behaviours in mice were induced by chronic restraint stress (CRS) and chronic unpredictable mild stress (CUMS). Palmitoylated proteins in the basolateral amygdala (BLA) were assessed by an acyl-biotin exchange assay. Genetic and pharmacological approaches were used to investigate the role of the DHHC2-mediated AKAP150 palmitoylation signalling pathway in depressive-like behaviours. Electrophysiological recording, western blotting and co-immunoprecipitation were performed to define the mechanistic pathway. KEY RESULTS Chronic stress successfully induced depressive-like behaviours in mice and enhanced AKAP150 palmitoylation in the BLA, and a palmitoylation inhibitor was enough to reverse these changes. Blocking the AKAP150-PKA interaction with the peptide Ht-31 abolished the CRS-induced AKAP150 palmitoylation signalling pathway. DHHC2 expression and palmitoylation levels were both increased after chronic stress. DHHC2 knockdown prevented CRS-induced depressive-like behaviours, as well as attenuating AKAP150 signalling and synaptic transmission in the BLA in CRS-treated mice. CONCLUSION AND IMPLICATIONS These results delineate that DHHC2 modulates chronic stress-induced depressive-like behaviours and synaptic transmission in the BLA via the AKAP150 palmitoylation signalling pathway, and this pathway may be considered as a promising novel therapeutic target for major depressive disorder.
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Affiliation(s)
- Si-Ying Wang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine and Life Science, Hainan Medical University, Haikou, China
| | - Shao-Wei Yang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Wei-Kai Chen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Yue-Ling Zhao
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Meng-Die Li
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Dan Tian
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Yue Pan
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Xiao-Shan Lin
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Xiao-Qian Zhu
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Zhen Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Jian-Min Liu
- Department of Pharmacy, Wuhan No. 1 Hospital, Wuhan, China
| | - Zhong-Meng Lai
- Department of Anesthesiology, Union Hospital, Fujian Medical University, Fuzhou, China
| | - Wu-Cheng Tao
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, China
| | - Zu-Cheng Shen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, China
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Shen ZC, Liu JM, Zheng JY, Li MD, Tian D, Pan Y, Tao WC, Gao SQ, Xia ZX. Regulation of anxiety-like behaviors by S-palmitoylation and S-nitrosylation in basolateral amygdala. Biomed Pharmacother 2023; 169:115859. [PMID: 37948993 DOI: 10.1016/j.biopha.2023.115859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/02/2023] [Accepted: 11/05/2023] [Indexed: 11/12/2023] Open
Abstract
Protein posttranslational modification regulates synaptic protein stability, sorting and trafficking, and is involved in emotional disorders. Yet the molecular mechanisms regulating emotional disorders remain unelucidated. Here we report unknown roles of protein palmitoylation/nitrosylation crosstalk in regulating anxiety-like behaviors in rats. According to the percentages of open arm duration in the elevated plus maze test, the rats were divided into high-, intermediate- and low-anxiety groups. The palmitoylation and nitrosylation levels were detected by acyl-biotin exchange assay, and we found low palmitoylation and high nitrosylation levels in the basolateral amygdala (BLA) of high-anxiety rats. Furthermore, we observed that 2-bromopalmitate (2-BP), a palmitoylation inhibitor, induced anxiety-like behaviors, accompanied with decreased amplitude and frequency of mEPSCs and mIPSCs in the BLA. Additionally, we also found that inhibiting nNOS activity with 7-nitroindazole (7-NI) in the BLA caused anxiolytic effects and reduced the synaptic transmission. Interestingly, diazepam (DZP) rapidly elevated the protein palmitoylation level and attenuated the protein nitrosylation level in the BLA. Specifically, similar to DZP, the voluntary wheel running exerted DZP-like anxiolytic action, and induced high palmitoylation and low nitrosylation levels in the BLA. Lastly, blocking the protein palmitoylation with 2-BP induced an increase in protein nitrosylation level, and attenuating the nNOS activity by 7-NI elevated the protein palmitoylation level. Collectively, these results show a critical role of protein palmitoylation/nitrosylation crosstalk in orchestrating anxiety behavior in rats, and it may serve as a potential target for anxiolytic intervention.
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Affiliation(s)
- Zu-Cheng Shen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China; Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou 350122, China.
| | - Jian-Min Liu
- Department of Pharmacy, Wuhan No. 1 Hospital, Wuhan 430000, China
| | - Jie-Yan Zheng
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Meng-Die Li
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Dan Tian
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Yue Pan
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Wu-Cheng Tao
- Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou 350122, China
| | - Shuang-Qi Gao
- Department of Neurosurgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China.
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine and Life Science, Hainan Medical University, Haikou 571199, China.
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Li MD, Wang L, Zheng YQ, Huang DH, Xia ZX, Liu JM, Tian D, OuYang H, Wang ZH, Huang Z, Lin XS, Zhu XQ, Wang SY, Chen WK, Yang SW, Zhao YL, Liu JA, Shen ZC. DHHC2 regulates fear memory formation, LTP, and AKAP150 signaling in the hippocampus. iScience 2023; 26:107561. [PMID: 37664599 PMCID: PMC10469764 DOI: 10.1016/j.isci.2023.107561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/07/2023] [Accepted: 08/02/2023] [Indexed: 09/05/2023] Open
Abstract
Palmitoyl acyltransferases (PATs) have been suggested to be involved in learning and memory. However, the underlying mechanisms have not yet been fully elucidated. Here, we found that the activity of DHHC2 was upregulated in the hippocampus after fear conditioning, and DHHC2 knockdown impaired fear induced memory and long-term potentiation (LTP). Additionally, the activity of DHHC2 and its synaptic expression were increased after high frequency stimulation (HFS) or glycine treatment. Importantly, fear learning selectively augmented the palmitoylation level of AKAP150, not PSD-95, and this effect was abolished by DHHC2 knockdown. Furthermore, 2-bromopalmitic acid (2-BP), a palmitoylation inhibitor, attenuated the increased palmitoylation level of AKAP150 and the interaction between AKAP150 and PSD-95 induced by HFS. Lastly, DHHC2 knockdown reduced the phosphorylation level of GluA1 at Ser845, and also induced an impairment of LTP in the hippocampus. Our results suggest that DHHC2 plays a critical role in regulating fear memory via AKAP150 signaling.
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Affiliation(s)
- Meng-Die Li
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Lu Wang
- Department of Nephrology, Fuzhou Children’s Hospital of Fujian Province, Affiliated Hospital of Fujian Medical University, Fuzhou 350001, China
| | - Yu-Qi Zheng
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Dan-Hong Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine and Life Science, Hainan Medical University, Haikou 571199, China
| | - Jian-Min Liu
- Department of Pharmacy, Wuhan No. 1 Hospital, Wuhan 430000, China
| | - Dan Tian
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Hui OuYang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Zi-Hao Wang
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Zhen Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Xiao-Shan Lin
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Xiao-Qian Zhu
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Si-Ying Wang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Wei-Kai Chen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Shao-Wei Yang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Yue-Ling Zhao
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Jia-An Liu
- Department of Medicinal Chemistry, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
| | - Zu-Cheng Shen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China
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Zhang SQ, Xia ZX, Deng Q, Yang PF, Long LH, Wang F, Chen JG. Repeated vagus nerve stimulation produces anxiolytic effects via upregulation of AMPAR function in centrolateral amygdala of male rats. Neurobiol Stress 2022; 18:100453. [PMID: 35685681 PMCID: PMC9170826 DOI: 10.1016/j.ynstr.2022.100453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/27/2022] [Accepted: 04/18/2022] [Indexed: 11/12/2022] Open
Abstract
Repeated vagus nerve stimulation (rVNS) exerts anxiolytic effect by activation of noradrenergic pathway. Centrolateral amygdala (CeL), a lateral subdivision of central amygdala, receives noradrenergic inputs, and its neuronal activity is positively correlated to anxiolytic effect of benzodiazepines. The activation of β-adrenergic receptors (β-ARs) could enhance glutamatergic transmission in CeL. However, it is unclear whether the neurobiological mechanism of noradrenergic system in CeL mediates the anxiolytic effect induced by rVNS. Here, we find that rVNS treatment produces an anxiolytic effect in male rats by increasing the neuronal activity of CeL. Electrophysiology recording reveals that rVNS treatment enhances the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR)-mediated excitatory neurotransmission in CeL, which is mimicked by β-ARs agonist isoproterenol or blocked by β-ARs antagonist propranolol. Moreover, chemogenetic inhibition of CeL neurons or pharmacological inhibition of β-ARs in CeL intercepts both enhanced glutamatergic neurotransmission and the anxiolytic effects by rVNS treatment. These results suggest that the amplified AMPAR trafficking in CeL via activation of β-ARs is critical for the anxiolytic effects induced by rVNS treatment. rVNS amplifies the noradrenergic system in CeL and results in anxiolysis. rVNS treatment enhances AMPAR-mediated excitatory neurotransmission CeL via β-ARs. Pharmacological inhibition β-ARs in CeL intercept the anxiolytic effects by rVNS. Exciting CeL neurons lead to an increase in inhibitory inputs into CeM neurons. Inhibiting CeL neurons abate inhibitory inputs into CeM and anxiolysis by rVNS.
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Luo YF, Ye XX, Fang YZ, Li MD, Xia ZX, Liu JM, Lin XS, Huang Z, Zhu XQ, Huang JJ, Tan DL, Zhang YF, Liu HP, Zhou J, Shen ZC. mTORC1 Signaling Pathway Mediates Chronic Stress-Induced Synapse Loss in the Hippocampus. Front Pharmacol 2022; 12:801234. [PMID: 34987410 PMCID: PMC8722735 DOI: 10.3389/fphar.2021.801234] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The mechanistic target of rapamycin complex 1 (mTORC1) signaling has served as a promising target for therapeutic intervention of major depressive disorder (MDD), but the mTORC1 signaling underlying MDD has not been well elucidated. In the present study, we investigated whether mTORC1 signaling pathway mediates synapse loss induced by chronic stress in the hippocampus. Methods: Chronic restraint stress-induced depression-like behaviors were tested by behavior tests (sucrose preference test, forced swim test and tail suspension test). Synaptic proteins and alternations of phosphorylation levels of mTORC1 signaling-associated molecules were measured using Western blotting. In addition, mRNA changes of immediate early genes (IEGs) and glutamate receptors were measured by RT-PCR. Rapamycin was used to explore the role of mTORC1 signaling in the antidepressant effects of fluoxetine. Results: After successfully establishing the chronic restraint stress paradigm, we observed that the mRNA levels of some IEGs were significantly changed, indicating the activation of neurons and protein synthesis alterations. Then, there was a significant downregulation of glutamate receptors and postsynaptic density protein 95 at protein and mRNA levels. Additionally, synaptic fractionation assay revealed that chronic stress induced synapse loss in the dorsal and ventral hippocampus. Furthermore, these effects were associated with the mTORC1 signaling pathway-mediated protein synthesis, and subsequently the phosphorylation of associated downstream signaling targets was reduced after chronic stress. Finally, we found that intracerebroventricular infusion of rapamycin simulated depression-like behavior and also blocked the antidepressant effects of fluoxetine. Conclusion: Overall, our study suggests that mTORC1 signaling pathway plays a critical role in mediating synapse loss induced by chronic stress, and has part in the behavioral effects of antidepressant treatment.
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Affiliation(s)
- Yu-Fei Luo
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China.,Clinical Medical Research Center, Hunan Prevention and Treatment Institute for Occupational Diseases, Changsha, China
| | - Xiao-Xia Ye
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Ying-Zhao Fang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Meng-Die Li
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine and Life Science, Hainan Medical University, Haikou, China
| | - Jian-Min Liu
- Department of Pharmacy, Wuhan No. 1 Hospital, Wuhan, China
| | - Xiao-Shan Lin
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Zhen Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Xiao-Qian Zhu
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Jun-Jie Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Dong-Lin Tan
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu-Fei Zhang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Hai-Ping Liu
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Jun Zhou
- Translational Medicine Center, Xi'an Chest Hospital, Medical College of Xi'an Jiaotong University, Xi'an, China
| | - Zu-Cheng Shen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
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6
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Shen ZC, Wu PF, Wang F, Xia ZX, Deng Q, Nie TL, Zhang SQ, Zheng HL, Liu WH, Lu JJ, Gao SQ, Yao XP, Long LH, Hu ZL, Chen JG. Gephyrin Palmitoylation in Basolateral Amygdala Mediates the Anxiolytic Action of Benzodiazepine. Biol Psychiatry 2019; 85:202-213. [PMID: 30454851 DOI: 10.1016/j.biopsych.2018.09.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 08/31/2018] [Accepted: 09/04/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND Benzodiazepines (BZDs) have been used to treat anxiety disorders for more than five decades as the allosteric modulator of the gamma-aminobutyric acid A receptor (GABAAR). Little is known about other mechanisms of BZDs. Here, we describe how the rapid stabilization of postsynaptic GABAAR is essential and sufficient for the anxiolytic effect of BZDs via a palmitoylation-dependent mechanism. METHODS Palmitoylated proteins in the basolateral amygdala (BLA) of rats with different anxious states were assessed by a biotin exchange protocol. Both pharmacological and genetic approaches were used to investigate the role of palmitoylation in anxiety behavior. Electrophysiological recording, reverse transcription polymerase chain reaction, Western blotting, and coimmunoprecipitation were used to investigate the mechanisms. RESULTS Highly anxious rats were accompanied by the deficiency of gephyrin palmitoylation and decreased the synaptic function of GABAAR in the BLA. We then identified that the dysfunction of DHHC12, a palmitoyl acyltransferase that specifically palmitoylates gephyrin, contributed to the high-anxious state. Furthermore, diazepam, as an anxiolytic drug targeting GABAARs, was found to increase gephyrin palmitoylation in the BLA via a GABAAR-dependent manner to activate DHHC12. The anxiolytic effect of diazepam was nearly abolished by the DHHC12 knockdown. Specifically, similar to the effect of BZD, the overexpression of DHHC12 in the BLA exerted a significant anxiolytic action, which was prevented by flumazenil. CONCLUSIONS Our results support the view that the strength of inhibitory synapse was controlled by gephyrin palmitoylation in vivo and proposes a previously unknown palmitoylation-centered mode of BZD's action.
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Affiliation(s)
- Zu-Cheng Shen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peng-Fei Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Laboratory of Neuropsychiatric Diseases, Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China; Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China; Key Laboratory of Neurological Diseases, Ministry of Education of China, Wuhan, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Laboratory of Neuropsychiatric Diseases, Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China; Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China; Collaborative-Innovation Center for Brain Science, Wuhan, China; Key Laboratory of Neurological Diseases, Ministry of Education of China, Wuhan, China.
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiao Deng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tai-Lei Nie
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shao-Qi Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui-Ling Zheng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wen-Hui Liu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jia-Jing Lu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shuang-Qi Gao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xia-Ping Yao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li-Hong Long
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Laboratory of Neuropsychiatric Diseases, Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China; Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China; Key Laboratory of Neurological Diseases, Ministry of Education of China, Wuhan, China
| | - Zhuang-Li Hu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Laboratory of Neuropsychiatric Diseases, Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China; Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China; Key Laboratory of Neurological Diseases, Ministry of Education of China, Wuhan, China
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; Laboratory of Neuropsychiatric Diseases, Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China; Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China; Collaborative-Innovation Center for Brain Science, Wuhan, China; Key Laboratory of Neurological Diseases, Ministry of Education of China, Wuhan, China.
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Xia ZX, Shen ZC, Zhang SQ, Wang J, Nie TL, Deng Q, Chen JG, Wang F, Wu PF. De-palmitoylation by N-(tert-Butyl) hydroxylamine inhibits AMPAR-mediated synaptic transmission via affecting receptor distribution in postsynaptic densities. CNS Neurosci Ther 2018; 25:187-199. [PMID: 29911316 DOI: 10.1111/cns.12996] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/24/2018] [Accepted: 05/28/2018] [Indexed: 12/16/2022] Open
Abstract
AIMS Palmitoylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) subunits or their "scaffold" proteins produce opposite effects on AMPAR surface delivery. Considering AMPARs have long been identified as suitable drug targets for central nervous system (CNS) disorders, targeting palmitoylation signaling to regulate AMPAR function emerges as a novel therapeutic strategy. However, until now, much less is known about the effect of palmitoylation-deficient state on AMPAR function. Herein, we set out to determine the effect of global de-palmitoylation on AMPAR surface expression and its function, using a special chemical tool, N-(tert-Butyl) hydroxylamine (NtBuHA). METHODS BS3 protein cross-linking, Western blot, immunoprecipitation, patch clamp, and biotin switch assay. RESULTS Bath application of NtBuHA (1.0 mM) reduced global palmitoylated proteins in the hippocampus of mice. Although NtBuHA (1.0 mM) did not affect the expression of ionotropic glutamate receptor subunits, it preferentially decreased the surface expression of AMPARs, not N-methyl-d-aspartate receptors (NMDARs). Notably, NtBuHA (1.0 mM) reduces AMPAR-mediated excitatory postsynaptic currents (mEPSCs) in the hippocampus. This effect may be largely due to the de-palmitoylation of postsynaptic density protein 95 (PSD95) and protein kinase A-anchoring proteins, both of which stabilized AMPAR synaptic delivery. Furthermore, we found that changing PSD95 palmitoylation by NtBuHA altered the association of PSD95 with stargazin, which interacted directly with AMPARs, but not NMDARs. CONCLUSION Our data suggest that the palmitoylation-deficient state initiated by NtBuHA preferentially reduces AMPAR function, which may potentially be used for the treatment of CNS disorders, especially infantile neuronal ceroid lipofuscinosis (Batten disease).
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Affiliation(s)
- Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zu-Cheng Shen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shao-Qi Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ji Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tai-Lei Nie
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiao Deng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China.,The Collaborative-Innovation Center for Brain Science, Wuhan, China.,The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China.,The Collaborative-Innovation Center for Brain Science, Wuhan, China.,The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, China
| | - Peng-Fei Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, China
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Zhang H, Li K, Chen HS, Gao SQ, Xia ZX, Zhang JT, Wang F, Chen JG. Dorsal raphe projection inhibits the excitatory inputs on lateral habenula and alleviates depressive behaviors in rats. Brain Struct Funct 2018; 223:2243-2258. [PMID: 29460052 DOI: 10.1007/s00429-018-1623-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 01/31/2018] [Indexed: 12/12/2022]
Abstract
Hypofunction of the serotonergic (5-HT) system has close relationship with the symptoms in major depressive disorders (MDD), however, the underlying neural circuitry mechanisms are not fully understood. Lateral habenula (LHb) plays a crucial role in aversive behaviors and is activated in conditions of depression. It has been reported that 5-HT inhibits the excitability of LHb neurons, leading to the hypothesis that decreased transmission of 5-HT would elevate the activity of LHb and therefore mediates depressive symptoms. Using retrograde tract tracing with cholera toxin subunit B, we find that dorsal raphe nucleus (DRN) sends primary 5-HT projection to the LHb. In vitro slice patch-clamp recording reveals that opto-stimulation of DRN inputs to the LHb suppresses the frequency of miniature excitatory postsynaptic current, while increases paired pulse ratio in LHb neurons, indicating 5-HT projection presynaptically suppresses the excitability of LHb neurons. In chronic unpredictable mild stress (CUMS) rat model of depression, optogenetic stimulation of DRN-LHb projection alleviates the depressive symptoms in CUMS models. Meanwhile, opto-inhibition of this circuit results in elevated c-fos expression in LHb and induces depression-like behaviors. This study demonstrates that the 5-HT projection from DRN to LHb suppresses the excitability of LHb neurons, and hypofunction of 5-HT transmission induces depressive behavior via the activation of LHb. Our results reveal the functional connectivity of DRN-LHb circuit and its antidepressant action, which may provide a novel target for the treatment of depression.
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Affiliation(s)
- Hai Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Kuan Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Hong-Sheng Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Shuang-Qi Gao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Jie-Ting Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China.
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China.
- The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, China.
- The Collaborative-Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China.
- The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China.
- The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, China.
- The Collaborative-Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan, 430030, China.
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9
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Wang CL, Xia ZX, Zhang GH, You JB, Yu H, Wang LL, Zhang MZ, Yang HB, Gu JP, Jin YK. [Time-dependent Protein Expressions of MMP-2 and MMP-9 in Liver Contusion Rats after Impact]. Fa Yi Xue Za Zhi 2017; 33:581-586. [PMID: 29441762 DOI: 10.3969/j.issn.1004-5619.2017.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To observe the protein expression patterns of matrix metalloproteinase (MMP)-2 and MMP-9 in the liver tissue of liver contusion rats at different time after impact. METHODS Fifty healthy adult male SD rats were randomly and evenly divided into control group and experimental groups (1 h, 3 h, 6 h, 12 h, 18 h, 24 h, 3 d, 5 d, 7 d after liver contusion). A rat liver contusion model was established by a free-falling device. The rats were killed at corresponding time, and the contused hepatic lobes were extracted. The protein expressions of MMP-2 and MMP-9 in contused liver tissue of the rats in each group were observed by immunohistochemical staining (SP method) and Western blotting. RESULTS After the liver contusion, the expression of positive cell and the protein semiquantitative result showed that the protein expression of MMP-2 enhanced at 6 h and peaked at 24 h, then decreased gradually at 3-5 d, and returned to normal levels at 7 d. The difference of expression between group and its previous adjacent group after 6 h (except 18 h) had statistical significance (P<0.05). The protein expression of MMP-9 rose obviously at 1 h after liver contusion and peaked at 18 h, then decreased gradually at 3-7 d which still higher than control group. The expression difference between group and its previous adjacent group (except 12 h and 24 h) had statistical significance (P<0.05). CONCLUSIONS The protein expressions of MMP-2 and MMP-9 in contused liver tissue after impact show good time-dependent patterns, which may provide important reference indicators for the time estimation of liver contusion.
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Affiliation(s)
- C L Wang
- People's Procuratorate of Liaoning Province, Shenyang 110032, China.,School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - Z X Xia
- Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - G H Zhang
- School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - J B You
- School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - H Yu
- School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - L L Wang
- School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - M Z Zhang
- School of Forensic Medicine, China Medical University, Shenyang 110122, China
| | - H B Yang
- People's Procuratorate of Liaoning Province, Shenyang 110032, China
| | - J P Gu
- People's Procuratorate of Hebei Province, Shijiazhuang 054002, China
| | - Y K Jin
- Technical Information Center, Supreme People's Procuratorate, Beijing 100144, China
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10
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Xia ZX, Li ZX, Zhang M, Sun LM, Zhang QF, Qiu XS. CARMA3 regulates the invasion, migration, and apoptosis of non-small cell lung cancer cells by activating NF-кB and suppressing the P38 MAPK signaling pathway. Exp Mol Pathol 2015; 100:353-60. [PMID: 26526492 DOI: 10.1016/j.yexmp.2015.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 10/20/2015] [Accepted: 10/21/2015] [Indexed: 11/19/2022]
Abstract
In our previous study, CARMA3 overexpression in lung cancer cells promoted cell proliferation and invasion; however, the mechanism underlying the role of CARMA3 in cancer cell invasion remained unclear. In the present study, knockdown of CARMA3 in A549 and H1299 cells suppressed cell invasion and migration, and downregulated matrix metalloprotease 9 expression at the protein and mRNA levels, as shown by Western blotting and real-time PCR. CARMA3 knockdown increased cell apoptosis, as shown by flow cytometry, increased the mRNA and protein expression levels of Bax and Caspase3, and downregulated Bcl-2 in A549 and H1299 cells. Phosphorylated P38 levels increased and NF-кB activation decreased following knockdown of CARMA3. SB203580, a P38 MAPK inhibitor, activated NF-кB, increased cell migration, and inhibited cell apoptosis after knockdown of CARMA3 compared to knockdown of CARMA3 without SB203580. These findings indicate that CARMA3 may suppress the activation of the P38 MAPK signaling pathway to regulate invasion, migration and apoptosis of lung cancer cells by activating NF-кB (P65) in the nucleus.
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Affiliation(s)
- Z X Xia
- Department of Pathology, the First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China; Department of Pathology, Center Hospital of Wuhan City, Wuhan, Hubei, China
| | - Z X Li
- Department of Radiology, the First Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
| | - M Zhang
- Department of Pathology, College of Basic Medical Sciences, Shenyang Medical College, Shenyang, Liaoning, China
| | - L M Sun
- Department of Pathology, the First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - Q F Zhang
- Department of Pathology, the First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China
| | - X S Qiu
- Department of Pathology, the First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, China.
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11
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Cong JC, Chen CS, Ma MX, Xia ZX, Liu DS, Zhang FY. Laparoscopic intersphincteric resection for low rectal cancer: comparison of stapled and manual coloanal anastomosis. Colorectal Dis 2014; 16:353-8. [PMID: 24460588 DOI: 10.1111/codi.12573] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 10/04/2013] [Indexed: 01/07/2023]
Abstract
AIM The study aim was to analyse the safety and feasibility of laparoscopic intersphincteric resection with stapled coloanal anastomosis for low rectal cancer. METHOD Between March 2009 and August 2010, 22 patients underwent laparoscopic intersphincteric resection with a stapled coloanal anastomosis without a diverting ileostomy. The results were compared retrospectively with hand-sewn coloanal anastomoses performed between January 2001 and May 2009, which included 55 open and 38 laparoscopic intersphincteric resections. The morbidity comparison only included data relevant to the anastomosis. Function was compared using the Saito function questionnaire and the Wexner score and only involved data relevant to the laparoscopy. RESULTS The anastomotic complication rates were similar for fistula, bleeding and neorectal mucosal prolapse (P = 0.526, P = 0.653 and P = 0.411, respectively). Anastomotic leakage and stricture formation of the stapled coloanal anastomosis were significantly lower than those of the hand-sewn coloanal anastomosis (P = 0.037 and P = 0.028, respectively). There were no significant differences in the Saito function questionnaire and the Wexner score between the stapled and hand-sewn coloanal anastomotic groups (all P > 0.05). CONCLUSION Laparoscopic intersphincteric resection with a stapled coloanal anastomosis is technically feasible and is less likely to result in anastomotic leakage and stricture formation than a hand-sewn anastomosis.
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Affiliation(s)
- J C Cong
- Department of Colorectal Surgery, Shengjing Hospital, China Medical University, Shenyang, China
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12
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Zhu M, Chen G, Chen D, Qi HG, Xia ZX, Wang SS, Huang YB, Zhang WJ, Chen ZK, Chen S. Induction of Accommodation Model by Combined RNA Interference Targeting 1,3-Galactosyltransferase Gene and Low-Dose GS-IB4 Lectin In Vitro. Transplant Proc 2006; 38:3193-5. [PMID: 17175219 DOI: 10.1016/j.transproceed.2006.10.135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE This study sought to mimic the interaction of xenograft endothelial cells and human serum in vitro after successfully silencing the expression of porcine alpha1,3-galactosyltransferase (alpha1,3GT) gene by RNA interference (RNAi), and to investigate the possibility of inducing accommodation in vitro by stimulation of alpha-Gal-specific binding lectin, Griffonia simplicifolia isolectin B4 (GS-IB4) and RNAi. MATERIALS AND METHODS Various alpha-Gal expression patterns on a pig endothelial cell immortalized line (PED) was achieved by serial doses of small interfering RNA (siRNA) targeting porcinc alpha1,3GT gene. alpha1,3GT-siRNA transfected PEDs were exposed to increasing doses of GS-IB4 lectin (0.5, 2, and 8 microg/mL) for 4 hours before incubation with normal human serum (NHS). Accommodation phenomenon of PEDs in NHS was observed by 51Cr release and antibody/complement binding assays. RESULTS With combined RNAi and low-dose GS-IB4 stimulation, PEDs remarkably inhibited complement-mediated cytotoxicity, which showed a better protective effect than using RNAi alone. At a concentration of 2 mug/mL, GS-IB4 exhibited the maximum protective effect. The expression of E-selectin on alpha1,3GT-siRNA transfected PEDs did not differ from that on parental PEDs with heat-inactivated NHS (HINHS) stimulation. Combined with GS-IB4 stimulation, however, it inhibited expression of E-selectin, which was GS-IB4 dose dependent, resulting in mean fluorescence intensity values of 98.5, 42.0, and 36.3 at 0.5, 2, and 8 microg/mL. The mRNA expression of the protective gene HO-1 was significantly up-regulated after treatment with RNAi and low-dose of GS-IB4. CONCLUSIONS Combined RNAi and low-dose GS-IB4 induced pig endothelial cell accommodation in vitro. The level of alpha-Gal expression played an important role in the induction of accommodation.
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Affiliation(s)
- M Zhu
- Key Laboratory of Organ Transplantation, Ministry of Education and Health, Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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13
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Wang SS, Han JY, Wu XW, Cao RH, Qi HG, Xia ZX, Chen D, Gong FL, Chen S. A study of HLA-G1 protection of porcine endothelial cells against human NK cell cytotoxicity. Transplant Proc 2004; 36:2473-4. [PMID: 15561285 DOI: 10.1016/j.transproceed.2004.08.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
UNLABELLED Human natural killer (NK) cells, which can directly lyse porcine endothelial cells, play an important role in xenotransplantation. HLA-G is a nonclassical major histocompatibility complex (MHC) class I molecules that has been implicated in protecting susceptible target cells from lysis by NK cells. The objective was to study the effect of protecting porcine endothelial cells transfected with HLA-G1 from human NK cell lysis. METHODS The recombinant expression vector pcDNA3-HLA-G1 was transfected into primary cultured porcine aortic endothelial cells (PAECs) by lipofection. Surface expression of HLA-G1 in transected PAECs was confirmed by an immunofluoresence technique. Peripheral blood mononuclear cells (PBMC) and NK cell line (NK92) were used as NK effects cells with pcDNA3-HLA-G1-transfected PAECs as targets in a MTT method using pcDNA3 transfection as a negative control. RESULTS Expression of HLA-G1 on PAECs conferred significant protection against NK-mediated lysis. The rate of NK92 cytotoxicity was reduced to 41.5% +/- 14.0% from 75.3% +/- 10.5% in the control group (P < .01). Similarly the rate of the PBMC cytotoxicity among different donors (n = 7) was reduced to 45.4% +/- 12.1% in contrast to 74.6% +/- 11.2% in the control group (P < .05). CONCLUSIONS HLA-G1 molecules can directly protect xenogeneic PAECs against attack by human NK cells. These results indicate that the expression of HLA-G1 on the porcine cell surface may provide a new approach to overcome NK-mediated immunity to xenografts.
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Affiliation(s)
- S S Wang
- Institute of Organ Transplantation, Key Laboratory appointed by China Ministry of Education and China Ministry of Health, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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14
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Wu J, Gan JH, Xia ZX. Crystallization and preliminary crystallographic studies of trichomaglin, a novel ribosome-inactivating protein. Acta Crystallogr D Biol Crystallogr 2000; 56:1466-7. [PMID: 11053854 DOI: 10.1107/s0907444900010660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2000] [Accepted: 07/28/2000] [Indexed: 11/11/2022]
Abstract
Trichomaglin, a novel ribosome-inactivating protein, has been crystallized in two crystal forms using the hanging-drop vapour-diffusion method. The form A and form B crystals belong to the orthorhombic space group P2(1)2(1)2(1) and the hexagonal space group P6(1) (or P6(5)), respectively. X-ray data have been collected to 3.3 and 2.2 A resolution for the form A and B crystals, respectively.
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Affiliation(s)
- J Wu
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China
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15
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Wu J, Gan JH, Xia ZX, Wang YH, Wang WH, Xue LL, Xie Y, Huang ZY. Addendum to crystal structure of recombinant trypsin-solubilized fragment of cytochrome b(5) and the structural comparison with Val61His mutant. Proteins 2000; 41:154. [PMID: 10944402 DOI: 10.1002/1097-0134(20001001)41:1<154::aid-prot170>3.0.co;2-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Wu J, Gan JH, Xia ZX, Wang YH, Wang WH, Xue LL, Xie Y, Huang ZX. Crystal structure of recombinant trypsin-solubilized fragment of cytochrome b(5) and the structural comparison with Val61His mutant. Proteins 2000; 40:249-57. [PMID: 10842340 DOI: 10.1002/(sici)1097-0134(20000801)40:2<249::aid-prot70>3.0.co;2-h] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The crystal structure of the recombinant trypsin-solubilized fragment of the microsomal cytochrome b(5) from bovine liver has been determined at 1.9 A resolution and compared with the reported crystal structure of the lipase-solubilized fragment of the membrane protein cytochrome b(5). The two structures are similar to each other. However, some detailed structural differences are observed: the conformation of the segment Asn16-Ser20 is quite different, some helices around the heme and some segments between the helices are shifted slightly, the heme is rotated about the normal of the mean plane of heme, one of the propionates of the heme exhibits a different conformation. The average coordination distances between the iron and the two nitrogen atoms of the imidazole ligands are the same in the two structures. Most of the structural differences can be attributed to the different intermolecular interactions which result from the crystal packing. The wild-type protein structure is also compared with its Val61His mutant, showing that the heme binding and the main chain conformations are basically identical with each other except for the local area of the mutation site. However, when Val61 is mutated to histidine, the large side chain of His61 is forced to point away from the heme pocket toward the solvent region, disturbing the micro-environment of the heme pocket and influencing the stability and the redox potential of the protein.
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Affiliation(s)
- J Wu
- State Key Laboratory of Bio-Organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China
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Gu YJ, Xia ZX. Crystal structures of the complexes of trichosanthin with four substrate analogs and catalytic mechanism of RNA N-glycosidase. Proteins 2000; 39:37-46. [PMID: 10737925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Four substrate analogs-nicotinamide adenine dinucleotide, adenylyl (3', 5') guanosine, guanylyl (3',5') adenosine, and adenosine 2', 5'-diphosphate-have been used to prepare the complexes with trichosanthin (TCS), a type I ribosome-inactivating protein that possesses the activity of N-glycosidase. The crystal structures of the complexes have been determined and refined at high resolution. The refined structures show that the N-glycosidic bonds of all the four substrate analogues are hydrolyzed and a common structure is shared by the four complexes, in which only adenine, the product of the enzymatic reaction, is bound in the active center. The structure is compared with those of native trichosanthin and a previously reported trichosanthin-NADPH complex in which the N-glycosidic bond is uncleaved. The structural comparison shows that the conformation of Tyr70 obviously differs from those in the latter two structures, i.e., the side chain of Tyr70 is rotated along its Cbeta-Cgamma bond by approximately 70 degrees. The water molecule found to be preassociated with the N-glycosidic bond in the TCS-NADPH complex structure and proposed to be the water candidate responsible for hydrolyzing the N-glycosidic bond disappears in the trichosanthin-product complex structure. Based on the comparison of the three structures representing the different stages of the enzymatic reaction, the catalytic mechanism of RNA N-glycosidase has been further elucidated. Proteins 2000;39:37-46.
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Affiliation(s)
- Y J Gu
- Shanghai Institute of Organic Chemistry, Shanghai, China
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18
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Xue LL, Wang YH, Xie Y, Yao P, Wang WH, Qian W, Huang ZX, Wu J, Xia ZX. Effect of mutation at valine 61 on the three-dimensional structure, stability, and redox potential of cytochrome b5. Biochemistry 1999; 38:11961-72. [PMID: 10508399 DOI: 10.1021/bi990893b] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To elucidate the role played by Val61 of cytochrome b(5), this residue of the tryptic fragment of bovine liver cytochrome b(5) was chosen for replacement with tyrosine (Val61Tyr), histidine (Val61His), glutamic acid (Val61Glu), and lysine (Val61Lys) by means of site-directed mutagenesis. The mutants Val61Tyr, Val61Glu, Val61His, and Val61Lys exhibit electronic spectra identical to that of the wild type, suggesting that mutation at Val61 did not affect the overall protein structure significantly. The redox potentials determined by differential pulse voltammetry were -10 (wild type), -25 (Val61Glu), -33 (Val61Tyr), 12 (Val61His), and 17 mV (Val61Lys) versus NHE. The thermal stabilities and urea-mediated denaturation of wild-type cytochrome b(5) and its mutants were in the following order: wild type > Val61Glu > Val61Tyr > Val61His > Val61Lys. The kinetics of denaturation of cytochrome b(5) by urea was also analyzed. The first-order rate constants of heme transfer between cytochrome b(5) and apomyoglobin at 20 +/- 0.2 degrees C were 0.25 +/- 0.01 (wild type), 0.42 +/- 0.02 (Val61Tyr), 0.93 +/- 0.04 (Val61Glu), 2.88 +/- 0.01 (Val61His), and 3.88 +/- 0.02 h(-)(1) (Val61Lys). The crystal structure of Val61His was determined using the molecular replacement method and refined at 2.1 A resolution, showing that the imidazole side chain of His61 points away from the heme-binding pocket and extends into the solvent, the coordination distances from Fe to NE2 atoms of two axial ligands are approximately 0.6 A longer than the reported value, and the hydrogen bond network involving Val61, the heme propionates, and three water molecules no longer exists. We conclude that the conserved residue Val61 is located at one of the key positions, the "electrostatic potential" around the heme-exposed area and the hydrophobicity of the heme pocket are determinant factors modulating the redox potential of cytochrome b(5), and the hydrogen bond network around the exposed heme edge is also an important factor affecting the heme stability.
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Affiliation(s)
- L L Xue
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, PRC
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19
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Abstract
Beta-Momorcharin (Mr approximately 29 kDa) is a single-chained ribosome-inactivating protein (RIP) with a branched hexasaccharide bound to Asn51. The crystal structure of beta-momorcharin has been determined using the molecular-replacement method and refined to 2. 55 A resolution. The final structural model gave an R factor of 17. 2% and root-mean-square deviations of 0.016 A and 1.76 degrees from ideal bond lengths and bond angles, respectively. beta-Momorcharin contains nine alpha-helices, two 310 helices and three beta-sheets, and its overall structure is similar to those of other single-chained RIPs. Residues Tyr70, Tyr109, Glu158 and Arg161 are expected to define the active site of beta-momorcharin as an rRNA N-glycosidase. The oligosaccharide is linked to the protein through an N-glycosidic bond, beta-GlcNAc-(1-N)-Asn51, and stretches from the surface of the N-terminal domain far from the active site, which suggests that it should not play a role in enzymatic function. The oligosaccharide of each beta-momorcharin molecule interacts with the protein through hydrogen bonds, although in the crystals most of these are intermolecular interactions with the protein atoms in an adjacent unit cell. This is the first example of an RIP structure which provides information about the three-dimensional structure and binding site of the oligosaccharide in the active chains of RIPs.
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Affiliation(s)
- Y R Yuan
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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Chen R, Xu YZ, Wu J, Pu Z, Jin SW, Liu WY, Xia ZX. Purification and characterization of trichomaglin--a novel ribosome-inactivating protein with abortifacient activity. Biochem Mol Biol Int 1999; 47:185-93. [PMID: 10205663 DOI: 10.1080/15216549900201193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Trichomaglin, a novel ribosome-inactivating protein, has been isolated from root tuber of a plant Maganlin (Trichosanthes Lepiniate, Cucurbitaceae). The isolation and purification procedure included ammonium sulfate precipitation, Sephadex G-75 chromatography and CM-Sephadex C-50 chromatography. The protein was identified to be homogeneous by SDS-PAGE and FPLC analysis. Its molecular weight is 24,673 dalton and isoelectric point is 5.8, determined by electrospray ionization mass spectroscopy and isoelectric focusing gel electrophoresis respectively. Trichomaglin can inhibit protein synthesis in rabbit reticulocyte lysate with ID50 of 10.1 nM. When rat ribosome was incubated with trichomaglin, a diagnostic RNA fragment appeared on polyacrylamide gel after ribosomal RNAs were treated with acidic aniline. It was concluded that trichomaglin is an RNA N-glycosidase. In addition, it has been verified to be an abortifacient protein.
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Affiliation(s)
- R Chen
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China
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Xia ZX, He YN, Dai WW, White SA, Boyd GD, Mathews FS. Detailed active site configuration of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 at 1.9 A resolution. Biochemistry 1999; 38:1214-20. [PMID: 9930981 DOI: 10.1021/bi9822574] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The three-dimensional structure of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 has been obtained in the presence of substrate using data recorded at a synchrotron. The structure of this approximately 140 kDa heterotetramer, refined at 1. 9 A resolution, reveals the detailed configuration of its redox cofactor, pyrroloquinoline quinone (PQQ). C4, one of the oxygen-bearing atoms of this orthoquinone is in a planar configuration while C5, which bears the other quinone oxygen, is tetrahedral, suggesting that the PQQ is in the semiquinone redox state. The substrate binding site has been identified close to PQQ and to the side chain of Asp297, the putative active site base. The proximity of the hydroxyl of methanol to C5 of PQQ compared to the greater separation of the substrate methyl group from C5 supports the addition-elimination reaction mechanism involving a hemiketal intermediate.
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Affiliation(s)
- Z X Xia
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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22
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Yuan YR, Xia ZX, Yang CH, Yang BH, Yeh M. A possible hydrolysis mechanism of beta-naphthyl acetate catalyzed by antibodies. Cell Res 1998; 8:219-30. [PMID: 9791735 DOI: 10.1038/cr.1998.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The mechanism of ester hydrolysis has been extensively studied; however, the precise function of active-site residues in promoting catalysis is unclear. We describe here the structural models for the complex of a catalytic antibody Fv fragment with a phosphonate transition-state analogue, constructed by using gene cloning, sequencing and molecular modeling, mainly based on a known X-ray structure of a catalytic antibody. Hydrophobic and electrostatic analyses of the Fv/analog and Fv/substrate interaction suggest the hydrolysis mechanism: Tyr L91 and Tyr H97 play important roles to stabilize the beta-naphthyl group of hapten through pi-stack; His H35 donates a pair of free electrons at the atom NE2 to an active water and let it to be a partial hydroxide, which attacks the carbon atom of the carbonyl group of the substrate. Both His H35 and Arg L96 can form hydrogen bonds and stabilize the anionic tetrahedral intermediate formed during turnover. This mechanism emphasizes that an active water bridge may be formed during hydrolysis process.
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Affiliation(s)
- Y R Yuan
- Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China.
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23
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Xiong JP, Xia ZX, Wang Y. Identification of a stable complex of trichosanthin with nicotinamide adenine dinucleotide phosphate. J Protein Chem 1995; 14:139-44. [PMID: 7576081 DOI: 10.1007/bf01980325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Trichosanthin, a type I ribosome-inactivating protein with RNA N-glycosidase activity, forms a stable complex with nicotinamide adenine dinucleotide phosphate, a substrate analog. Difference UV spectroscopy, fluorescence spectroscopy, and 31P NMR are used to identify the formation of the complex, followed by a crystal structure analysis carried out to elucidate the active-site structure of trichosanthin. The determination of germinal vesicle breakdown indicates that the complex does not, at least for abortion-inducing activity, result in competitive inhibition to the protein.
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Affiliation(s)
- J P Xiong
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences
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24
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Harris TK, Davidson VL, Chen L, Mathews FS, Xia ZX. Ionic strength dependence of the reaction between methanol dehydrogenase and cytochrome c-551i: evidence of conformationally coupled electron transfer. Biochemistry 1994; 33:12600-8. [PMID: 7918485 DOI: 10.1021/bi00208a010] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The quinoprotein methanol dehydrogenase and cytochrome c-551i are two soluble acidic proteins that form a physiological complex in which electrons are transferred from pyrroloquinoline quinone to heme. The oxidation of methanol dehydrogenase by the cytochrome was studied as a function of ionic strength using stopped-flow spectroscopy. The dissociation constant (Kd) for complex formation decreased 2-fold with increasing ionic strength from 0.21 to 1.3 M and increased at higher ionic strengths. The rate constant for the electron transfer reaction (kET) increased 2-fold with increasing ionic strength from 0.21 to 1.3 M and decreased at higher ionic strengths. The variation of Kd and kET over this range of ionic strengths was described by Van Leeuwen theory, which takes into account monopole-dipole and dipole-dipole forces, in addition to the monopole-monopole force, to predict the interactions between large molecules. Analysis of the kinetic results in terms of these electrostatic interactions indicated the probable orientations for protein-protein binding and electron transfer. To explain the ionic strength dependence of the observed kET, a model is presented in which the true kET is reduced by a factor Kc, an equilibrium constant that describes some rearrangement of the proteins after a nonoptimal collision to produce the most efficient orientation for electron transfer. This model is consistent with the notion that the large reorganizational energy obtained from temperature-dependence studies of this electron transfer reaction [Harris, T. K., & Davidson, V. L. (1993) Biochemistry 32, 14145-14150] is due to such an intracomplex rearrangement.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T K Harris
- Department of Biochemistry, University of Mississippi Medical Center, Jackson 39216
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25
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Xiong JP, Xia ZX, Wang Y. Crystal structure of trichosanthin-NADPH complex at 1.7 A resolution reveals active-site architecture. Nat Struct Biol 1994; 1:695-700. [PMID: 7634073 DOI: 10.1038/nsb1094-695] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We describe here the crystal structure of the trichosanthin-NADPH complex determined at a resolution of 1.7 A. The adenine base stacks between Tyr 70 and Tyr 111. Arg 163, Glu 160 and Tyr 70 form hydrogen bonds to N(3), O(3') and, through a water molecule, to N(9) of adenosine, respectively. This is the first high resolution structure of a complex between a ribosome-inactivating protein and a substrate analogue, in which the electron density of the N-glycosidic bond is well defined and the preassociated water, thought to be responsible for hydrolyzing the N-C bond, is also explicitly elucidated.
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Affiliation(s)
- J P Xiong
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences
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26
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Abstract
Beta-Momorcharin from seeds of Momordica charantia, Cucurbitaceae Linn, has been crystallized using a vapor diffusion method. The crystals belong to space group P1 with unit cell parameters: a = 49.09 A, b = 50.58 A, c = 61.12 A, alpha = 72.98 degrees, beta = 78.39 degrees, gamma = 76.97 degrees. There are two molecules in the unit cell and the diffraction data up to 2.4 A resolution were collected on an X-200B area detector, giving an Rmerge of 7.8%.
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Affiliation(s)
- J P Xiong
- Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China
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White S, Boyd G, Mathews FS, Xia ZX, Dai WW, Zhang YF, Davidson VL. The active site structure of the calcium-containing quinoprotein methanol dehydrogenase. Biochemistry 1993; 32:12955-8. [PMID: 8241148 DOI: 10.1021/bi00211a002] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Pyrroloquinoline quinone (PQQ), widely found in nature, serves as the redox cofactor in bacterial methanol dehydrogenase (MEDH), a heterotetrameric enzyme that oxidizes methanol to formaldehyde. The refined structure of MEDH at 2.4-A resolution, based on recently obtained amino acid sequence data, reveals that the PQQ, located in a central channel of the disk-shaped protein, is sandwiched between a Trp side chain and a very unusual vicinal disulfide. A Ca2+ ion forms a bridge between PQQ and the protein molecule, very close to a putative substrate binding pocket. The vicinal disulfide may form during PQQ incorporation and possibly act to hold the latter in place.
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Affiliation(s)
- S White
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
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Xia ZX, Dai WW, Xiong JP, Hao ZP, Davidson VL, White S, Mathews FS. The three-dimensional structures of methanol dehydrogenase from two methylotrophic bacteria at 2.6-A resolution. J Biol Chem 1992; 267:22289-97. [PMID: 1331050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The structures of methanol dehydrogenase (MEDH) from two closely related methylotrophic bacteria, Methylophilus methylotrophus and W3A1, have been determined at 2.6-A resolution. The molecule, a quinoprotein of molecular mass of about 138 kDa, contains two heavy (H) and two light (L) subunits of unknown sequence and two molecules of noncovalently associated pyrroloquinoline quinone. The two enzymes crystallize isomorphously in space group P2(1) with one H2L2 heterotetramer in the asymmetric unit. The electron density map of the M. methylophilus enzyme was obtained by multiple isomorphous replacement with anomalous scattering and improved by solvent leveling and electron density averaging. For model building, the amino acid sequence of MEDH from Paracoccus denitrificans for the H subunit and from Methylobacterium extorquens AM1 for the L subunit were used to represent the unknown amino acid sequence. At the present time, 579 and 57 amino acid residues for the large and small subunits, respectively, have been fitted into the map. The phases for MEDH from M. methylophilus were used directly to analyze the W3A1 structure, and both structures were refined to R-factors (where R = sigma[Fo-Fc[/sigma Fo) of 0.277 and 0.266, respectively. The L subunit contains a long alpha-helix and an extended N-terminal segment, both lying on the molecular surface of the H subunit. The H subunit contains eight antiparallel beta-sheets, each consisting of four strands arranged topologically like the letter W. The eight Ws are arranged circularly, forming the main disc-shaped body of the subunit, with some short helices and loops connecting the consecutive Ws, as well as some excursions within and between some of the Ws. The pyrroloquinoline quinone prosthetic group is located in the central channel of the large subunit near the surface of the molecule. The topology of the eight-W folding unit is similar to those of the six- and seven-W folding units previously reported for three other proteins, neuraminidase, methylamine dehydrogenase, and galactose oxidase.
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Affiliation(s)
- Z X Xia
- Shanghai Institute of Organic Chemistry, Academia Sinica, Shanghai, China
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Abstract
The crystal structure of flavocytochrome b2 has been solved at 3.0 A resolution by the method of multiple isomorphous replacement with anomalous scattering. Area detector data from native and two heavy-atom derivative crystals were used. The phases were refined by the B.C. Wang phase-filtering procedure utilizing the 67% (v/v) solvent content of the crystals. A molecular model was built first on a minimap and then on computer graphics from a combination of maps both averaged and not averaged about the molecular symmetry axis. The structure was extended to 2.4 A resolution using film data recorded at a synchrotron and refined by the Hendrickson-Konnert procedure. The molecule, a tetramer of Mr 230,000, is located on a crystallographic 2-fold axis and possesses local 4-fold symmetry. Each subunit is composed of two domains, one binding a heme and the other an FMN prosthetic group. In subunit 1, both the cystochrome and the flavin-binding domain are visible in the electron density map. In subunit 2 the cytochrome domain is disordered. However, in the latter, a molecule of pyruvate, the product of the enzymatic reaction, is bound at the active site. The cytochrome domain consists of residues 1 to 99 and is folded in a fashion similar to the homologous soluble fragment of cytochrome b5. The flavin binding domain contains a parallel beta 8 alpha 8 barrel structure and is composed of residues 100 to 486. The remaining 25 residues form a tail that wraps around the molecular 4-fold axis and is in contact with each remaining subunit. The FMN moiety, which is located at the C-terminal end of the central beta-barrel, is mostly sequestered from solvent; it forms hydrogen bond interactions with main- and side-chain atoms from six of the eight beta-strands. The interaction of Lys349 with atoms N-1 and O-2 of the flavin ring is probably responsible for stabilization of the anionic form of the flavin semiquinone and hydroquinone and enhancing the reactivity of atom N-5 toward sulfite. The binding of pyruvate at the active site in subunit 2 is stabilized by interaction of its carboxylate group with the side-chain atoms of Arg376 and Tyr143. Residues His373 and Tyr254 interact with the keto-oxygen atom and are involved in catalysis. In contrast, four water molecules occupy the substrate-binding site in subunit 1 and Tyr143 forms a hydrogen bond to the ordered heme propionate group. Otherwise the two flavin-binding domains are identical within experimental error.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- Z X Xia
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO 63110
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Xia ZX, Hao ZP, Mathews FS, Davidson VL. Crystallization and preliminary X-ray crystallographic study of the quinoprotein methanol dehydrogenase from bacterium W3A1. FEBS Lett 1989; 258:175-6. [PMID: 2687021 DOI: 10.1016/0014-5793(89)81644-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Methanol dehydrogenase from bacterium W3A1 has been crystallized by the macroseeding method to give single crystals suitable for three-dimensional structural study at resolution greater than 3 A. The crystals belong to the group P2(1), and have unit cell dimensions a = 124.13 A, b = 62.87 A, c = 84.71 A, and beta = 92.89 degrees. There is one dimeric molecule of 114,600 Da per asymmetric unit.
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Affiliation(s)
- Z X Xia
- Shanghai Institute of Organic Chemistry, Academia Sinica, PR China
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Xia ZX, Shamala N, Bethge PH, Lim LW, Bellamy HD, Xuong NH, Lederer F, Mathews FS. Three-dimensional structure of flavocytochrome b2 from baker's yeast at 3.0-A resolution. Proc Natl Acad Sci U S A 1987; 84:2629-33. [PMID: 3554243 PMCID: PMC304711 DOI: 10.1073/pnas.84.9.2629] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The structure of flavocytochrome b2 from baker's yeast was solved at 3.0-A resolution by the multiple isomorphous replacement method combined with solvent leveling procedures, using data collected from an area detector. The tetramer of Mr 230,000 has 4-fold symmetry. Each subunit contains a cytochrome domain consisting of the first 100 residues, a flavin-binding domain containing the next 386 residues, and an extended C-terminal tail of 25 residues. The cytochrome domain closely resembles microsomal cytochrome b5, whereas the flavin-binding domain contains a parallel beta 8/alpha 8 barrel motif similar to glycolate oxidase and trimethylamine dehydrogenase. Two of the four cytochrome domains are disordered in the crystals. The flavin ring and heme group are separated by about 16 A between their centers, and their planes are inclined by about 17 degrees to each other.
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Li ZB, Zhao H, Xia ZX. [Comparative analysis in the treatment of cerebral ischemia in children and adult patients by extra-intracranial arterial anastomosis]. Zhonghua Wai Ke Za Zhi 1986; 24:498-9, 511. [PMID: 3816475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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