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Zhu S, Sun R, Guo X, Bao Y, Zhang D. Regulation, targets and functions of CHK. Front Cell Dev Biol 2022; 10:1068952. [PMID: 36568988 PMCID: PMC9780368 DOI: 10.3389/fcell.2022.1068952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
Src family kinases (SFKs) play pivotal roles in multiple signaling pathways (Yeatman, 2004). SFK activity is inhibited by phosphorylation at its C-terminal tyrosine, by CSK (C-terminal Src kinase) and CHK (CSK-homologous kinase). CHK expression is restricted to normal hematopoietic cells, brain, and colon tissues. Downregulation of CHK in brain and colon tumors contributes to tumorigenicity in these tissues. CHK does not phosphorylate Src efficiently, however, in contrast to CSK, CHK inhibits Src kinase activity allosterically. Although the functions of CHK are still largely unknown, potential substrates of CHK including β-synuclein, α-tubulin, α-spectrin, 14-3-3, and Hsp90 have been identified. CHK is regulated epigenetically via promoter methylation. As the unknown roles of CHK are beginning to be revealed, current knowledge of regulation, molecular targets and functions of CHK is summarized, and important topics for future CHK research are discussed.
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Affiliation(s)
- Shudong Zhu
- School of Medicine, Nantong University, Nantong, China,Argus Pharmaceuticals, Changsha, China,*Correspondence: Shudong Zhu,
| | - Rong Sun
- School of Medicine, Nantong University, Nantong, China
| | | | | | - Dianzheng Zhang
- Department of Bio-medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, United States
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3
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Hayashi J, Carver JA. β-Synuclein: An Enigmatic Protein with Diverse Functionality. Biomolecules 2022; 12:142. [PMID: 35053291 PMCID: PMC8773819 DOI: 10.3390/biom12010142] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/09/2022] [Accepted: 01/12/2022] [Indexed: 12/24/2022] Open
Abstract
α-Synuclein (αS) is a small, unstructured, presynaptic protein expressed in the brain. Its aggregated form is a major component of Lewy bodies, the large proteinaceous deposits in Parkinson's disease. The closely related protein, β-Synuclein (βS), is co-expressed with αS. In vitro, βS acts as a molecular chaperone to inhibit αS aggregation. As a result of this assignation, βS has been largely understudied in comparison to αS. However, recent reports suggest that βS promotes neurotoxicity, implying that βS is involved in other cellular pathways with functions independent of αS. Here, we review the current literature pertaining to human βS in order to understand better the role of βS in homeostasis and pathology. Firstly, the structure of βS is discussed. Secondly, the ability of βS to (i) act as a molecular chaperone; (ii) regulate synaptic function, lipid binding, and the nigrostriatal dopaminergic system; (iii) mediate apoptosis; (iv) participate in protein degradation pathways; (v) modulate intracellular metal levels; and (vi) promote cellular toxicity and protein aggregation is explored. Thirdly, the P123H and V70M mutations of βS, which are associated with dementia with Lewy bodies, are discussed. Finally, the importance of post-translational modifications on the structure and function of βS is reviewed. Overall, it is concluded that βS has both synergistic and antagonistic interactions with αS, but it may also possess important cellular functions independent of αS.
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Affiliation(s)
| | - John A. Carver
- Research School of Chemistry, The Australian National University, Acton, ACT 2601, Australia;
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4
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Advani G, Lim YC, Catimel B, Lio DSS, Ng NLY, Chüeh AC, Tran M, Anasir MI, Verkade H, Zhu HJ, Turk BE, Smithgall TE, Ang CS, Griffin M, Cheng HC. Csk-homologous kinase (Chk) is an efficient inhibitor of Src-family kinases but a poor catalyst of phosphorylation of their C-terminal regulatory tyrosine. Cell Commun Signal 2017; 15:29. [PMID: 28784162 PMCID: PMC5547543 DOI: 10.1186/s12964-017-0186-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 07/28/2017] [Indexed: 11/10/2022] Open
Abstract
Background C-terminal Src kinase (Csk) and Csk-homologous kinase (Chk) are the major endogenous inhibitors of Src-family kinases (SFKs). They employ two mechanisms to inhibit SFKs. First, they phosphorylate the C-terminal tail tyrosine which stabilizes SFKs in a closed inactive conformation by engaging the SH2 domain in cis. Second, they employ a non-catalytic inhibitory mechanism involving direct binding of Csk and Chk to the active forms of SFKs that is independent of phosphorylation of their C-terminal tail. Csk and Chk are co-expressed in many cell types. Contributions of the two mechanisms towards the inhibitory activity of Csk and Chk are not fully clear. Furthermore, the determinants in Csk and Chk governing their inhibition of SFKs by the non-catalytic inhibitory mechanism are yet to be defined. Methods We determined the contributions of the two mechanisms towards the inhibitory activity of Csk and Chk both in vitro and in transduced colorectal cancer cells. Specifically, we assayed the catalytic activities of Csk and Chk in phosphorylating a specific peptide substrate and a recombinant SFK member Src. We employed surface plasmon resonance spectroscopy to measure the kinetic parameters of binding of Csk, Chk and their mutants to a constitutively active mutant of the SFK member Hck. Finally, we determined the effects of expression of recombinant Chk on anchorage-independent growth and SFK catalytic activity in Chk-deficient colorectal cancer cells. Results Our results revealed Csk as a robust enzyme catalysing phosphorylation of the C-terminal tail tyrosine of SFKs but a weak non-catalytic inhibitor of SFKs. In contrast, Chk is a poor catalyst of SFK tail phosphorylation but binds SFKs with high affinity, enabling it to efficiently inhibit SFKs with the non-catalytic inhibitory mechanism both in vitro and in transduced colorectal cancer cells. Further analyses mapped some of the determinants governing this non-catalytic inhibitory mechanism of Chk to its kinase domain. Conclusions SFKs are activated by different upstream signals to adopt multiple active conformations in cells. SFKs adopting these conformations can effectively be constrained by the two complementary inhibitory mechanisms of Csk and Chk. Furthermore, the lack of this non-catalytic inhibitory mechanism accounts for SFK overactivation in the Chk-deficient colorectal cancer cells. Electronic supplementary material The online version of this article (doi:10.1186/s12964-017-0186-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gahana Advani
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia.,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ya Chee Lim
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,PAP Rashidah Sa'adatul Bolkiah Institute of Health Sciences, Universiti Brunei Darussalam, Gadong, Brunei Darussalam
| | - Bruno Catimel
- Walter and Eliza Hall Institute for Medical Research and Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Daisy Sio Seng Lio
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia.,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Nadia L Y Ng
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia.,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Anderly C Chüeh
- Walter and Eliza Hall Institute for Medical Research and Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Mai Tran
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Mohd Ishtiaq Anasir
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Heather Verkade
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Hong-Jian Zhu
- Department of Surgery, University of Melbourne, Royal Melbourne Hospital, Parkville, VIC, 3052, Australia
| | - Benjamin E Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ching-Seng Ang
- Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Michael Griffin
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Heung-Chin Cheng
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia. .,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia. .,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia.
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Zaferanloo B, Bhattacharjee S, Ghorbani MM, Mahon PJ, Palombo EA. Amylase production by Preussia minima, a fungus of endophytic origin: optimization of fermentation conditions and analysis of fungal secretome by LC-MS. BMC Microbiol 2014; 14:55. [PMID: 24602289 PMCID: PMC3995912 DOI: 10.1186/1471-2180-14-55] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 02/26/2014] [Indexed: 12/01/2022] Open
Abstract
Background Environmental screening programs are used to find new enzymes that may be utilized in large-scale industrial processes. Among microbial sources of new enzymes, the rationale for screening fungal endophytes as a potential source of such enzymes relates to the hypothesised mutualistic relationship between the endophyte and its host plant. There is a need for new microbial amylases that are active at low temperature and alkaline conditions as these would find industrial applications as detergents. Results An α-amylase produced by Preussia minima, isolated from the Australian native plant, Eremophilia longifolia, was purified to homogeneity through fractional acetone precipitation and Sephadex G-200 gel filtration, followed by DEAE-Sepharose ion exchange chromatography. The purified α-amylase showed a molecular mass of 70 kDa which was confirmed by zymography. Temperature and pH optima were 25°C and pH 9, respectively. The enzyme was activated and stabilized mainly by the metal ions manganese and calcium. Enzyme activity was also studied using different carbon and nitrogen sources. It was observed that enzyme activity was highest (138 U/mg) with starch as the carbon source and L-asparagine as the nitrogen source. Bioreactor studies showed that enzyme activity was comparable to that obtained in shaker cultures, which encourages scale-up fermentation for enzyme production. Following in-gel digestion of the purified protein by trypsin, a 9-mer peptide was sequenced and analysed by LC-ESI-MS/MS. The partial amino acid sequence of the purified enzyme presented similarity to α-amylase from Magnaporthe oryzae. Conclusions The findings of the present study indicate that the purified α-amylase exhibits a number of promising properties that make it a strong candidate for application in the detergent industry. To our knowledge, this is the first amylase isolated from a Preussia minima strain of endophytic origin.
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Affiliation(s)
| | | | | | | | - Enzo A Palombo
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
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Hashimoto M, La Spada AR. β-synuclein in the pathogenesis of Parkinson’s disease and related α-synucleinopathies: emerging roles and new directions. FUTURE NEUROLOGY 2012. [DOI: 10.2217/fnl.12.5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An important turning point in understanding Parkinson’s disease was the realization that altered function of α-synuclein (αS) is central to disease pathogenesis. β-synuclein (βS), the homolog of αS, received limited attention initially, but further work indicated that βS may be involved in the pathogenesis of Parkinson’s disease and other α-synucleinopathies. βS can protect against neurodegeneration caused by αS, and mutations in the βS gene have been linked to dementia with Lewy bodies. When we created transgenic mice expressing the P123H βS mutation, we observed neurodegeneration characterized by axonal pathology and gliosis. Furthermore, P123H-βS transgenic mice exhibited memory dysfunction, suggesting that alteration of neuroprotective βS function contributes to non-motor symptoms. Similar to other amyloidogenic proteins, βS may yield neurodegeneration through both loss-of-function and gain-of-function mechanisms. Such diverse modes of action need to be carefully considered, as βS is emerging as an attractive candidate for therapy development.
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Affiliation(s)
- Makoto Hashimoto
- Division of Sensory & Motor Systems, Tokyo Metropolitan Institute of Medical Science, 2–1-6 Kamikitasawa, Setagaya-ku, Tokyo 156-0057, Japan
| | - Albert R La Spada
- Departments of Pediatrics, Cellular & Molecular Medicine, and Neurosciences, Division of Biological Sciences, and the Institute for Genomic Medicine, University of California, San Diego; La Jolla, CA 92093, USA; Pediatrics and Cellular & Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, MC 0642, La Jolla, CA 92093-0642, USA
- Rady Children’s Hospital, San Diego, CA 92123, USA
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