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Yang Y, Shu C, Li P, Igumenova TI. Structural Basis of Protein Kinase Cα Regulation by the C-Terminal Tail. Biophys J 2019; 114:1590-1603. [PMID: 29642029 DOI: 10.1016/j.bpj.2017.12.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/07/2017] [Accepted: 12/21/2017] [Indexed: 10/17/2022] Open
Abstract
Protein kinase C (PKC) isoenzymes are multi-modular proteins activated at the membrane surface to regulate signal transduction processes. When activated by second messengers, PKC undergoes a drastic conformational and spatial transition from the inactive cytosolic state to the activated membrane-bound state. The complete structure of either state of PKC remains elusive. We demonstrate, using NMR spectroscopy, that the isolated Ca2+-sensing membrane-binding C2 domain of the conventional PKCα interacts with a conserved hydrophobic motif of the kinase C-terminal region, and we report a structural model of the complex. Our data suggest that the C-terminal region plays a dual role in regulating the PKC activity: activating, through sensitization of PKC to intracellular Ca2+ oscillations; and auto-inhibitory, through its interaction with a conserved positively charged region of the C2 domain.
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Affiliation(s)
- Yuan Yang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Chang Shu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Tatyana I Igumenova
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas.
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2
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Protein kinase C mechanisms that contribute to cardiac remodelling. Clin Sci (Lond) 2017; 130:1499-510. [PMID: 27433023 DOI: 10.1042/cs20160036] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/18/2016] [Indexed: 12/12/2022]
Abstract
Protein phosphorylation is a highly-regulated and reversible process that is precisely controlled by the actions of protein kinases and protein phosphatases. Factors that tip the balance of protein phosphorylation lead to changes in a wide range of cellular responses, including cell proliferation, differentiation and survival. The protein kinase C (PKC) family of serine/threonine kinases sits at nodal points in many signal transduction pathways; PKC enzymes have been the focus of considerable attention since they contribute to both normal physiological responses as well as maladaptive pathological responses that drive a wide range of clinical disorders. This review provides a background on the mechanisms that regulate individual PKC isoenzymes followed by a discussion of recent insights into their role in the pathogenesis of diseases such as cancer. We then provide an overview on the role of individual PKC isoenzymes in the regulation of cardiac contractility and pathophysiological growth responses, with a focus on the PKC-dependent mechanisms that regulate pump function and/or contribute to the pathogenesis of heart failure.
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3
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Novel Features of DAG-Activated PKC Isozymes Reveal a Conserved 3-D Architecture. J Mol Biol 2016; 428:121-141. [DOI: 10.1016/j.jmb.2015.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/01/2015] [Indexed: 01/17/2023]
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Antal CE, Callender JA, Kornev AP, Taylor SS, Newton AC. Intramolecular C2 Domain-Mediated Autoinhibition of Protein Kinase C βII. Cell Rep 2015; 12:1252-60. [PMID: 26279568 DOI: 10.1016/j.celrep.2015.07.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/23/2015] [Accepted: 07/17/2015] [Indexed: 11/26/2022] Open
Abstract
The signaling output of protein kinase C (PKC) is exquisitely controlled, with its disruption resulting in pathophysiologies. Identifying the structural basis for autoinhibition is central to developing effective therapies for cancer, where PKC activity needs to be enhanced, or neurodegenerative diseases, where PKC activity should be inhibited. Here, we reinterpret a previously reported crystal structure of PKCβII and use docking and functional analysis to propose an alternative structure that is consistent with previous literature on PKC regulation. Mutagenesis of predicted contact residues establishes that the Ca(2+)-sensing C2 domain interacts intramolecularly with the kinase domain and the carboxyl-terminal tail, locking PKC in an inactive conformation. Ca(2+)-dependent bridging of the C2 domain to membranes provides the first step in activating PKC via conformational selection. Although the placement of the C1 domains remains to be determined, elucidation of the structural basis for autoinhibition of PKCβII unveils a unique direction for therapeutically targeting PKC.
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Affiliation(s)
- Corina E Antal
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92037, USA
| | - Julia A Callender
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92037, USA
| | - Alexandr P Kornev
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - Susan S Taylor
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA.
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5
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Abstract
Protein kinase C (PKC) is a family of Ser/Thr kinases that regulate a multitude of cellular processes through participation in the phosphoinositide signaling pathway. Significant research efforts have been directed at understanding the structure, function, and regulatory modes of the enzyme since its discovery and identification as the first receptor for tumor-promoting phorbol esters. The activation of PKC involves a transition from the cytosolic autoinhibited latent form to the membrane-associated active form. The membrane recruitment step is accompanied by the conformational rearrangement of the enzyme, which relieves autoinhibitory interactions and thereby allows PKC to phosphorylate its targets. The multidomain structure and intrinsic flexibility of PKC present remarkable challenges and opportunities for the biophysical and structural biology studies of this class of enzymes and their interactions with membranes, the major focus of this Current Topic. I will highlight the recent advances in the field, outline the current challenges, and identify areas where biophysics and structural biology approaches can provide insight into the isoenzyme-specific regulation of PKC activity.
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6
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Qiu W, Zhang F, Steinberg SF. The protein kinase D1 COOH terminus: marker or regulator of enzyme activity? Am J Physiol Cell Physiol 2014; 307:C606-10. [PMID: 25080487 DOI: 10.1152/ajpcell.00155.2014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein kinase D1 (PKD1) is a Ser/Thr kinase implicated in a wide variety of cellular responses. PKD1 activation is generally attributed to a PKC-dependent pathway that leads to phosphorylation of the activation loop at Ser(744)/Ser(748). This modification increases catalytic activity, including that toward an autophosphorylation site (Ser(916)) in a postsynaptic density-95/disks large/zonula occludens-1 (PDZ)-binding motif at the extreme COOH terminus. However, there is growing evidence that PKD1 activation can also result from a PKC-independent autocatalytic reaction at Ser(744)/Ser(748) and that certain stimuli increase in PKD1 phosphorylation at Ser(744)/S(748) without an increase in autophosphorylation at Ser(916). This study exposes a mechanism that results in a discrepancy between PKD1 COOH-terminal autocatalytic activity and activity toward other substrates. We show that PKD1 constructs harboring COOH-terminal epitope tags display high levels of in vitro activation loop autocatalytic activity and activity toward syntide-2 (a peptide substrate), but no Ser(916) autocatalytic activity. Cell-based studies show that the COOH-terminal tag, adjacent to PKD1's PDZ1-binding motif, does not grossly influence PKD1 partitioning between soluble and particulate fractions in resting cells or PKD1 translocation to the particulate fraction following treatment with PMA. However, a COOH-terminal tag that confers a high level of activation loop autocatalytic activity decreases the PKC requirement for agonist-dependent PKD1 activation in cells. The recognition that COOH-terminal tags alter PKD1's pharmacological profile is important from a technical standpoint. The altered dynamics and activation mechanisms for COOH-terminal-tagged PKD1 enzymes also could model the signaling properties of localized pools of enzyme anchored through the COOH terminus to PDZ domain-containing scaffolding proteins.
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Affiliation(s)
- Weihua Qiu
- Department of Pharmacology, Columbia University, New York, New York
| | - Fan Zhang
- Department of Pharmacology, Columbia University, New York, New York
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7
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Swanson CJ, Ritt M, Wang W, Lang MJ, Narayan A, Tesmer JJ, Westfall M, Sivaramakrishnan S. Conserved modular domains team up to latch-open active protein kinase Cα. J Biol Chem 2014; 289:17812-29. [PMID: 24790081 DOI: 10.1074/jbc.m113.534750] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Signaling proteins comprised of modular domains have evolved along with multicellularity as a method to facilitate increasing intracellular bandwidth. The effects of intramolecular interactions between modular domains within the context of native proteins have been largely unexplored. Here we examine intra- and intermolecular interactions in the multidomain signaling protein, protein kinase Cα (PKCα). We identify three interactions between two activated PKC molecules that synergistically stabilize a nanomolar affinity homodimer. Disruption of the homodimer results in a loss of PKC-mediated ERK1/2 phosphorylation, whereas disruption of the auto-inhibited state promotes the homodimer and prolongs PKC membrane localization. These observations support a novel regulatory mechanism wherein homodimerization dictates the equilibrium between the auto-inhibited and active states of PKC by sequestering auto-inhibitory interactions. Our findings underscore the physiological importance of context-dependent modular domain interactions in cell signaling.
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Affiliation(s)
| | | | - William Wang
- Department of Cell and Developmental Biology, Department of Cardiac Surgery
| | | | - Arvind Narayan
- Department of Biomedical Engineering, Life Sciences Institute, and
| | - John J Tesmer
- From the Biophysics Program, the Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Margaret Westfall
- Department of Cardiac Surgery, Department of Biomedical Engineering, Life Sciences Institute, and
| | - Sivaraj Sivaramakrishnan
- From the Biophysics Program, Department of Cell and Developmental Biology, Department of Biomedical Engineering, Life Sciences Institute, and
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Antal CE, Violin JD, Kunkel MT, Skovsø S, Newton AC. Intramolecular conformational changes optimize protein kinase C signaling. ACTA ACUST UNITED AC 2014; 21:459-469. [PMID: 24631122 DOI: 10.1016/j.chembiol.2014.02.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 01/31/2014] [Accepted: 02/02/2014] [Indexed: 11/25/2022]
Abstract
Optimal tuning of enzyme signaling is critical for cellular homeostasis. We use fluorescence resonance energy transfer reporters in live cells to follow conformational transitions that tune the affinity of a multidomain signal transducer, protein kinase C (PKC), for optimal response to second messengers. This enzyme comprises two diacylglycerol sensors, the C1A and C1B domains, that have a sufficiently high intrinsic affinity for ligand so that the enzyme would be in a ligand-engaged, active state if not for mechanisms that mask its domains. We show that both diacylglycerol sensors are exposed in newly synthesized PKC and that conformational transitions following priming phosphorylations mask the domains so that the lower affinity sensor, the C1B domain, is the primary diacylglycerol binder. The conformational rearrangements of PKC serve as a paradigm for how multimodule transducers optimize their dynamic range of signaling.
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Affiliation(s)
- Corina E Antal
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Jonathan D Violin
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Maya T Kunkel
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
| | - Søs Skovsø
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA; Institute for Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA.
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9
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Jezierska J, Goedhart J, Kampinga HH, Reits EA, Verbeek DS. SCA14 mutation V138E leads to partly unfolded PKCγ associated with an exposed C-terminus, altered kinetics, phosphorylation and enhanced insolubilization. J Neurochem 2013; 128:741-51. [DOI: 10.1111/jnc.12491] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 10/03/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Justyna Jezierska
- Department of Genetics; University of Groningen; University Medical Center Groningen; Groningen The Netherlands
| | - Joachim Goedhart
- Section Molecular Cytology; van Leeuwenhoek Centre for Advanced Microscopy; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam The Netherlands
| | - Harm H. Kampinga
- Department of Cell Biology; University Medical Center Groningen; University of Groningen; Groningen The Netherlands
| | - Eric A. Reits
- Department of Cell Biology and Histology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Dineke S. Verbeek
- Department of Genetics; University of Groningen; University Medical Center Groningen; Groningen The Netherlands
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10
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Yang Y, Igumenova TI. The C-terminal V5 domain of Protein Kinase Cα is intrinsically disordered, with propensity to associate with a membrane mimetic. PLoS One 2013; 8:e65699. [PMID: 23762412 PMCID: PMC3675085 DOI: 10.1371/journal.pone.0065699] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 04/26/2013] [Indexed: 12/20/2022] Open
Abstract
The C-terminal V5 domain is one of the most variable domains in Protein Kinase C isoforms (PKCs). V5 confers isoform specificity on its parent enzyme through interactions with isoform-specific adaptor proteins and possibly through specific intra-molecular interactions with other PKC domains. The structural information about V5 domains in solution is sparse. The objective of this work was to determine the conformational preferences of the V5 domain from the α isoform of PKC (V5α) and evaluate its ability to associate with membrane mimetics. We show that V5α and its phosphorylation-mimicking variant, dmV5α, are intrinsically disordered protein domains. Phosphorylation-mimicking mutations do not alter the overall conformation of the polypeptide backbone, as evidenced by the local nature of chemical shift perturbations and the secondary structure propensity scores. However, the population of the “cis-trans” conformer of the Thr638-Pro639-Pro640 turn motif, which has been implicated in the down-regulation of PKCα via peptidyl-prolyl isomerase Pin1, increases in dmV5α, along with the conformational flexibility of the region between the turn and hydrophobic motifs. Both wild type and dmV5α associate with micelles made of a zwitterionic detergent, n-dodecylphosphocholine. Upon micelle binding, V5α acquires a higher propensity to form helical structures at the conserved “NFD” motif and the entire C-terminal third of the domain. The ability of V5α to partition into the hydrophobic micellar environment suggests that it may serve as a membrane anchor during the PKC maturation process.
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Affiliation(s)
- Yuan Yang
- Department of Biochemistry and Biophysics, Texas A & M University, College Station, Texas, United States of America
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11
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Farah CA, Sossin WS. The role of C2 domains in PKC signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:663-83. [PMID: 22453964 DOI: 10.1007/978-94-007-2888-2_29] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
More than two decades ago, the discovery of the first C2 domain in conventional Protein Kinase Cs (cPKCs) and of its role as a calcium-binding motif began to shed light on the activation mechanism of this family of Serine/Threonine kinases which are involved in several critical signal transduction pathways. In this chapter, we review the current knowledge of the structure and the function of the different C2 domains in PKCs. The C2 domain of cPKCs is a calcium sensor and its calcium-dependent binding to phospholipids is crucial for kinase activation. While the functional role of the cPKC C2 domain is better understood, phylogenetic analysis revealed that the novel C2 domain is more ancient and related to the C2 domain in the fungal PKC family, while the cPKC C2 domain is first associated with PKC in metazoans. The C2 domain of novel PKCs (nPKCs) does not contain a calcium-binding motif but still plays a critical role in nPKCs activation by regulating C1-C2 domain interactions and consequently C2 domain-mediated inhibition in both the nPKCs of the epsilon family and the nPKCs of the delta family. Moreover, the C2 domain of the nPKCs of the delta family was shown to recognize phosphotyrosines in a novel mode different from the ones observed for the Src Homology 2 (SH2) and the phosphotyrosine binding domains (PTB). By binding to phosphotyrosines, the C2 domain regulates the activation of this subclass of PKCs. The C2 domain was also shown to be involved in protein-protein interactions and binding to the receptor for activated C-kinase (RACKs) thus contributing to the subcellular localization of PKCs. In summary, the C2 domain is a critical player that can sense the activated signaling pathway in response to external stimuli to specifically regulate the different conventional and novel PKC isoforms.
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Affiliation(s)
- Carole A Farah
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, BT 105, 3801 University Street, Montreal, QC H3A 2B4, Canada.
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12
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Abstract
Nestled at the tip of a branch of the kinome, protein kinase C (PKC) family members are poised to transduce signals emanating from the cell surface. Cell membranes provide the platform for PKC function, supporting the maturation of PKC through phosphorylation, its allosteric activation by binding specific lipids, and, ultimately, promoting the downregulation of the enzyme. These regulatory mechanisms precisely control the level of signaling-competent PKC in the cell. Disruption of this regulation results in pathophysiological states, most notably cancer, where PKC levels are often grossly altered. This review introduces the PKC family and then focuses on recent advances in understanding the cellular regulation of its diacylglycerol-regulated members.
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Affiliation(s)
- Alexandra C Newton
- Dept. of Pharmacology, Univ. of California at San Diego, La Jolla, 92093, USA.
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Gallegos LL, Newton AC. Spatiotemporal dynamics of lipid signaling: protein kinase C as a paradigm. IUBMB Life 2009; 60:782-9. [PMID: 18720411 DOI: 10.1002/iub.122] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The lipid second messenger diacylglycerol (DAG) controls the rate, amplitude, duration, and location of protein kinase C (PKC) activity in the cell. There are three classes of PKC isozymes and, of these, the conventional and novel isozymes are acutely controlled by DAG. The kinetics of DAG production at various intracellular membranes, the intrinsic affinity of specific isoforms for DAG-containing membranes, the coordinated use of additional membrane-binding modules, the intramolecular regulation of DAG sensitivity, and the competition from other DAG-responsive proteins together result in a unique, context-dependent activation signature for each isoform. This review focuses on the spatiotemporal dynamics of PKC activation and how it is controlled by lipid second messengers.
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Affiliation(s)
- Lisa L Gallegos
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093-0721, USA
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Verbeek DS, Goedhart J, Bruinsma L, Sinke RJ, Reits EA. PKC gamma mutations in spinocerebellar ataxia type 14 affect C1 domain accessibility and kinase activity leading to aberrant MAPK signaling. J Cell Sci 2008; 121:2339-49. [PMID: 18577575 DOI: 10.1242/jcs.027698] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Spinocerebellar ataxia type 14 (SCA14) is a neurodegenerative disorder caused by mutations in the neuronal-specific protein kinase C gamma (PKCgamma) gene. Since most mutations causing SCA14 are located in the PKCgamma C1B regulatory subdomain, we investigated the impact of three C1B mutations on the intracellular kinetics, protein conformation and kinase activity of PKCgamma in living cells. SCA14 mutant PKCgamma proteins showed enhanced phorbol-ester-induced kinetics when compared with wild-type PKCgamma. The mutations led to a decrease in intramolecular FRET of PKCgamma, suggesting that they ;open' PKCgamma protein conformation leading to unmasking of the phorbol ester binding site in the C1 domain. Surprisingly, SCA14 mutant PKCgamma showed reduced kinase activity as measured by phosphorylation of PKC reporter MyrPalm-CKAR, as well as downstream components of the MAPK signaling pathway. Together, these results show that SCA14 mutations located in the C1B subdomain ;open' PKCgamma protein conformation leading to increased C1 domain accessibility, but inefficient activation of downstream signaling pathways.
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Affiliation(s)
- Dineke S Verbeek
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, AZ Amsterdam, The Netherlands.
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