1
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Li T, Wang Y, Natran A, Zhang Y, Wang H, Du K, Qin P, Yuan H, Chen W, Tu B, Inzé D, Dubois M. C-TERMINAL DOMAIN PHOSPHATASE-LIKE 3 contributes to GA-mediated growth and flowering by interaction with DELLA proteins. New Phytol 2024. [PMID: 38594216 DOI: 10.1111/nph.19742] [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] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 03/14/2024] [Indexed: 04/11/2024]
Abstract
Gibberellic acid (GA) plays a central role in many plant developmental processes and is crucial for crop improvement. DELLA proteins, the core suppressors in the GA signaling pathway, are degraded by GA via the 26S proteasomal pathway to release the GA response. However, little is known about the phosphorylation-mediated regulation of DELLA proteins. In this study, we combined GA response assays with protein-protein interaction analysis to infer the connection between Arabidopsis thaliana DELLAs and the C-TERMINAL DOMAIN PHOSPHATASE-LIKE 3 (CPL3), a phosphatase involved in the dephosphorylation of RNA polymerase II. We show that CPL3 directly interacts with DELLA proteins and promotes DELLA protein stability by inhibiting its degradation by the 26S proteasome. Consequently, CPL3 negatively modulates multiple GA-mediated processes of plant development, including hypocotyl elongation, flowering time, and anthocyanin accumulation. Taken together, our findings demonstrate that CPL3 serves as a novel regulator that could improve DELLA stability and thereby participate in GA signaling transduction.
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Affiliation(s)
- Ting Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, 611130, Chengdu, China
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Gent, Belgium
| | - Yongqin Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, 611130, Chengdu, China
| | - Annelore Natran
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Gent, Belgium
| | - Yi Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, 611130, Chengdu, China
| | - Hao Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Kangxi Du
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Peng Qin
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Hua Yuan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, 611130, Chengdu, China
| | - Weilan Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Bin Tu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, 611130, Chengdu, Sichuan, China
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Gent, Belgium
| | - Marieke Dubois
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Gent, Belgium
- Center for Plant Systems Biology, VIB, 9052, Gent, Belgium
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2
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Wu D, Van der Hoeven G, Claes Z, Van Eynde A, Bollen M. DNA damage-induced allosteric activation of protein phosphatase PP1:NIPP1 through Src kinase-induced circularization of NIPP1. FEBS J 2024. [PMID: 38303113 DOI: 10.1111/febs.17064] [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: 07/03/2023] [Revised: 12/06/2023] [Accepted: 12/28/2023] [Indexed: 02/03/2024]
Abstract
Protein phosphatase-1 (PP1) complexed to nuclear inhibitor of PP1 (NIPP1) limits DNA repair through dephosphorylation of NIPP1-recruited substrates. However, the PP1:NIPP1 holoenzyme is completely inactive under basal conditions, hinting at a DNA damage-regulated activation mechanism. Here, we report that DNA damage caused the activation of PP1:NIPP1 after a time delay of several hours through phosphorylation of NIPP1 at the C-terminal tyrosine 335 (Y335) by a Src-family kinase. PP1:NIPP1 activation partially resulted from the dissociation of the C terminus of NIPP1 from the active site of PP1. In addition, the released Y335-phosphorylated C terminus interacted with the N terminus of NIPP1 to enhance substrate recruitment by the flanking forkhead-associated (FHA) domain. Constitutive activation of PP1:NIPP1 by knock-in of a phospho-mimicking (Y335E) NIPP1 mutant led to the hypo-phosphorylation of FHA ligands and an accumulation of DNA double-strand breaks. Our data indicate that PP1:NIPP1 activation through circularization of NIPP1 is a late response to DNA damage that contributes to the timely recovery from damage repair.
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Affiliation(s)
- Dan Wu
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Gerd Van der Hoeven
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Zander Claes
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, KU Leuven Department of Cellular and Molecular Medicine, University of Leuven, Belgium
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3
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Salter EA, Wierzbicki A, Honkanen RE, Swingle MR. Quantum-based modeling implies that bidentate Arg 89-substrate binding enhances serine/threonine protein phosphatase-2A(PPP2R5D/PPP2R1A/PPP2CA)-mediated dephosphorylation. Front Cell Dev Biol 2023; 11:1141804. [PMID: 37377738 PMCID: PMC10291244 DOI: 10.3389/fcell.2023.1141804] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
PP2A-serine/threonine protein phosphatases function as heterotrimeric holoenzymes, composed of a common scaffold (A-subunit encoded by PPP2R1A/PPP2R1B), a common catalytic (C-subunit encoded by PPP2CA/PPP2CB), and one of many variable regulatory (B) subunits. The site of phosphoprotein phosphatase (PPP) hydrolysis features a bimetal system (M1/M2), an associated bridge hydroxide [W1(OH-)], and a highly-conserved core sequence. In the presumptive common mechanism, the phosphoprotein's seryl/threonyl phosphate coordinates the M1/M2 system, W1(OH-) attacks the central P atom, rupturing the antipodal bond, and simultaneously, a histidine/aspartate tandem protonates the exiting seryl/threonyl alkoxide. Based on studies of PPP5C, a conserved arginine proximal to M1 is also expected to bind the substrate's phosphate group in a bidentate fashion. However, in PP2A isozymes, the role of the arginine (Arg89) in hydrolysis is not clear because two independent structures for PP2A(PPP2R5C) and PP2A(PPP2R5D) show that Arg89 engages in a weak salt bridge at the B:C interface. These observations raise the question of whether hydrolysis proceeds with or without direct involvement of Arg89. The interaction of Arg89 with B:Glu198 in PP2A(PPP2R5D) is significant because the pathogenic E198K variant of B56δ is associated with irregular protein phosphorylation levels and consequent developmental disorders (Jordan's Syndrome; OMIM #616355). In this study, we perform quantum-based hybrid [ONIOM(UB3LYP/6-31G(d):UPM7)] calculations on 39-residue models of the PP2A(PPP2R5D)/pSer (phosphoserine) system to estimate activation barriers for hydrolysis in the presence of bidentate Arg89-substrate binding and when Arg89 is otherwise engaged in the salt-bridge interaction. Our solvation-corrected results yield ΔH‡ ≈ ΔE‡ = +15.5 kcal/mol for the former case, versus +18.8 kcal/mol for the latter, indicating that bidentate Arg89-substrate binding is critical for optimal catalytic function of the enzyme. We speculate that PP2A(PPP2R5D) activity is suppressed by B:Glu198 sequestration of C:Arg89 under native conditions, whereas the PP2A(PPP2R5D)-holoenzyme containing the E198K variant has a positively-charged lysine in this position that alters normal function.
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Affiliation(s)
- E. Alan Salter
- Department of Chemistry, University of South Alabama, Mobile, AL, United States
| | - Andrzej Wierzbicki
- Department of Chemistry, University of South Alabama, Mobile, AL, United States
| | - Richard E. Honkanen
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, United States
| | - Mark R. Swingle
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL, United States
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4
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Khan R, Kulasiri D, Samarasinghe S. Functional repertoire of protein kinases and phosphatases in synaptic plasticity and associated neurological disorders. Neural Regen Res 2021; 16:1150-1157. [PMID: 33269764 PMCID: PMC8224123 DOI: 10.4103/1673-5374.300331] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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] [Indexed: 01/21/2023] Open
Abstract
Protein phosphorylation and dephosphorylation are two essential and vital cellular mechanisms that regulate many receptors and enzymes through kinases and phosphatases. Ca2+- dependent kinases and phosphatases are responsible for controlling neuronal processing; balance is achieved through opposition. During molecular mechanisms of learning and memory, kinases generally modulate positively while phosphatases modulate negatively. This review outlines some of the critical physiological and structural aspects of kinases and phosphatases involved in maintaining postsynaptic structural plasticity. It also explores the link between neuronal disorders and the deregulation of phosphatases and kinases.
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Affiliation(s)
- Raheel Khan
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University; Department of Molecular Biosciences, Lincoln University, Christchurch, New Zealand
| | - Don Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University; Department of Molecular Biosciences, Lincoln University, Christchurch, New Zealand
| | - Sandhya Samarasinghe
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
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5
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Heroes E, Van der Hoeven G, Choy MS, Garcia JDP, Ferreira M, Nys M, Derua R, Beullens M, Ulens C, Peti W, Van Meervelt L, Page R, Bollen M. Structure-Guided Exploration of SDS22 Interactions with Protein Phosphatase PP1 and the Splicing Factor BCLAF1. Structure 2019; 27:507-518.e5. [PMID: 30661852 DOI: 10.1016/j.str.2018.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 10/09/2018] [Accepted: 12/03/2018] [Indexed: 01/29/2023]
Abstract
SDS22 is an ancient regulator of protein phosphatase-1 (PP1). Our crystal structure of SDS22 shows that its twelve leucine-rich repeats adopt a banana-shaped fold that is shielded from solvent by capping domains at its extremities. Subsequent modeling and biochemical studies revealed that the concave side of SDS22 likely interacts with PP1 helices α5 and α6, which are distal from the binding sites of many previously described PP1 interactors. Accordingly, we found that SDS22 acts as a "third" subunit of multiple PP1 holoenzymes. The crystal structure of SDS22 also revealed a large basic surface patch that enables binding of a phosphorylated form of splicing factor BCLAF1. Taken together, our data provide insights into the formation of PP1:SDS22 and the recruitment of additional interaction proteins, such as BCLAF1.
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6
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Fu J, Yang Q, Li Y, Li P, Wang L, Li X. A mechanism by which Astragalus polysaccharide protects against ROS toxicity through inhibiting the protein dephosphorylation of boar sperm preserved at 4 °C. J Cell Physiol 2018; 233:5267-5280. [PMID: 29231961 DOI: 10.1002/jcp.26321] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [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: 09/01/2017] [Accepted: 12/01/2017] [Indexed: 01/08/2023]
Abstract
Numerous studies have shown that Astragalus polysaccharide (APS) has strong antioxidant effects and high practical value for preserving semen at low temperatures in vitro. However, to date, little attention has been paid to the precise mechanism of APS in sperm preservation at 4 °C. Thus, to gain further insight into the protective effects of APS, the present study was performed to assess the changes in sperm quality parameters, antioxidant capacity, ATP content, and protein phosphorylation levels. Here, we demonstrated that supplementation with APS could effectively preserve boar sperm quality parameters such as sperm motility, acrosome integrity, and mitochondrial membrane potential. Moreover, we found that the positive effects of APS on boar sperm quality were mainly due to the elimination of excessive mitochondrial ROS, the improvement of antioxidant capacities and the enhancement of ATP levels. Interestingly, by conducting a series of studies on protein phosphorylation, we also discovered that APS could protect boar sperm from oxidative stress and energy deficiency through inhibiting the protein dephosphorylation caused by ROS via the cAMP-PKA signaling pathway. To our knowledge, this is the first exploration of the molecular mechanism underlying the protective roles of APS toward ROS toxicity from the perspective of energy metabolism and protein modification. This study comprehensively provides novel insights into the action mechanism of the protective effects of antioxidants on sperm stored at 4 °C and reveals the practical feasibility of using APS as a boar semen extender supplement for assisted reproductive technology.
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Affiliation(s)
- Jieli Fu
- Shanghai Key Lab of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Qiangzhen Yang
- Shanghai Key Lab of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Yuhua Li
- Shanghai Key Lab of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Peifei Li
- Shanghai Key Lab of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Lirui Wang
- Shanghai Key Lab of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Xinhong Li
- Shanghai Key Lab of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China
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7
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Mishra A, Oulès B, Pisco AO, Ly T, Liakath-Ali K, Walko G, Viswanathan P, Tihy M, Nijjher J, Dunn SJ, Lamond AI, Watt FM. A protein phosphatase network controls the temporal and spatial dynamics of differentiation commitment in human epidermis. eLife 2017; 6:27356. [PMID: 29043977 PMCID: PMC5667932 DOI: 10.7554/elife.27356] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [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: 04/01/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022] Open
Abstract
Epidermal homeostasis depends on a balance between stem cell renewal and terminal differentiation. The transition between the two cell states, termed commitment, is poorly understood. Here, we characterise commitment by integrating transcriptomic and proteomic data from disaggregated primary human keratinocytes held in suspension to induce differentiation. Cell detachment induces several protein phosphatases, five of which - DUSP6, PPTC7, PTPN1, PTPN13 and PPP3CA – promote differentiation by negatively regulating ERK MAPK and positively regulating AP1 transcription factors. Conversely, DUSP10 expression antagonises commitment. The phosphatases form a dynamic network of transient positive and negative interactions that change over time, with DUSP6 predominating at commitment. Boolean network modelling identifies a mandatory switch between two stable states (stem and differentiated) via an unstable (committed) state. Phosphatase expression is also spatially regulated in vivo and in vitro. We conclude that an auto-regulatory phosphatase network maintains epidermal homeostasis by controlling the onset and duration of commitment.
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Affiliation(s)
- Ajay Mishra
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom.,Department of Chemical Engineering and Biotechnology, Cambridge Infinitus Research Centre, University of Cambridge, Cambridge, United Kingdom
| | - Bénédicte Oulès
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom
| | - Angela Oliveira Pisco
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom
| | - Tony Ly
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.,Wellcome Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Gernot Walko
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom
| | | | - Matthieu Tihy
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom.,Laboratory of Cerebral Physiology, Université Paris Descartes, Paris, France
| | - Jagdeesh Nijjher
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom
| | - Sara-Jane Dunn
- Microsoft Research, Cambridge, United Kingdom.,Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Angus I Lamond
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fiona M Watt
- Centre for Stem Cells and Regenerative Medicine, King's College London, London, United Kingdom
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8
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Tatjer L, Sacristán-Reviriego A, Casado C, González A, Rodríguez-Porrata B, Palacios L, Canadell D, Serra-Cardona A, Martín H, Molina M, Ariño J. Wide-Ranging Effects of the Yeast Ptc1 Protein Phosphatase Acting Through the MAPK Kinase Mkk1. Genetics 2016; 202:141-56. [PMID: 26546002 PMCID: PMC4701081 DOI: 10.1534/genetics.115.183202] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [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: 09/29/2015] [Accepted: 11/02/2015] [Indexed: 11/18/2022] Open
Abstract
The Saccharomyces cerevisiae type 2C protein phosphatase Ptc1 is required for a wide variety of cellular functions, although only a few cellular targets have been identified. A genetic screen in search of mutations in protein kinase-encoding genes able to suppress multiple phenotypic traits caused by the ptc1 deletion yielded a single gene, MKK1, coding for a MAPK kinase (MAPKK) known to activate the cell-wall integrity (CWI) Slt2 MAPK. In contrast, mutation of the MKK1 paralog, MKK2, had a less significant effect. Deletion of MKK1 abolished the increased phosphorylation of Slt2 induced by the absence of Ptc1 both under basal and CWI pathway stimulatory conditions. We demonstrate that Ptc1 acts at the level of the MAPKKs of the CWI pathway, but only the Mkk1 kinase activity is essential for ptc1 mutants to display high Slt2 activation. We also show that Ptc1 is able to dephosphorylate Mkk1 in vitro. Our results reveal the preeminent role of Mkk1 in signaling through the CWI pathway and strongly suggest that hyperactivation of Slt2 caused by upregulation of Mkk1 is at the basis of most of the phenotypic defects associated with lack of Ptc1 function.
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Affiliation(s)
- Laura Tatjer
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Almudena Sacristán-Reviriego
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), 28040 Madrid, Spain
| | - Carlos Casado
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Asier González
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Boris Rodríguez-Porrata
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Lorena Palacios
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), 28040 Madrid, Spain
| | - David Canadell
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Albert Serra-Cardona
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
| | - Humberto Martín
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), 28040 Madrid, Spain
| | - María Molina
- Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), 28040 Madrid, Spain
| | - Joaquín Ariño
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Barcelona, Spain
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9
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Tang XW, Hsu CC, Schloss JV, Faiman MD, Wu E, Yang CY, Wu JY. Protein phosphorylation and taurine biosynthesis in vivo and in vitro. J Neurosci 1997; 17:6947-51. [PMID: 9278530 PMCID: PMC6573280] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Taurine is known to be involved in many important physiological functions. Here we report that both in vivo and in vitro the taurine-synthesizing enzyme in the brain, namely cysteine sulfinic acid decarboxylase (CSAD), is activated when phosphorylated and inhibited when dephosphorylated. Furthermore, protein kinase C and protein phosphatase 2C have been identified as the enzymes responsible for phosphorylation and dephosphorylation of CSAD, respectively. In addition, the effect of neuronal depolarization on CSAD activity and 32P incorporation into CSAD in neuronal cultures is also included. A model to link neuronal excitation and CSAD activation by a Ca2+-dependent protein kinase is proposed.
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Affiliation(s)
- X W Tang
- Department of Physiology and Cell Biology, University of Kansas, Lawrence, Kansas 66045-2106, USA
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