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Gorenberg EL, Massaro Tieze S, Yücel B, Zhao HR, Chou V, Wirak GS, Tomita S, Lam TT, Chandra SS. Identification of substrates of palmitoyl protein thioesterase 1 highlights roles of depalmitoylation in disulfide bond formation and synaptic function. PLoS Biol 2022; 20:e3001590. [PMID: 35358180 PMCID: PMC9004782 DOI: 10.1371/journal.pbio.3001590] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 04/12/2022] [Accepted: 03/02/2022] [Indexed: 12/30/2022] Open
Abstract
Loss-of-function mutations in the depalmitoylating enzyme palmitoyl protein thioesterase 1 (PPT1) cause neuronal ceroid lipofuscinosis (NCL), a devastating neurodegenerative disease. The substrates of PPT1 are largely undescribed, posing a limitation on molecular dissection of disease mechanisms and therapeutic development. Here, we provide a resource identifying >100 novel PPT1 substrates. We utilized Acyl Resin-Assisted Capture (Acyl RAC) and mass spectrometry to identify proteins with increased in vivo palmitoylation in PPT1 knockout (KO) mouse brains. We then validated putative substrates through direct depalmitoylation with recombinant PPT1. This stringent screen elucidated diverse PPT1 substrates at the synapse, including channels and transporters, G-protein–associated molecules, endo/exocytic components, synaptic adhesion molecules, and mitochondrial proteins. Cysteine depalmitoylation sites in transmembrane PPT1 substrates frequently participate in disulfide bonds in the mature protein. We confirmed that depalmitoylation plays a role in disulfide bond formation in a tertiary screen analyzing posttranslational modifications (PTMs). Collectively, these data highlight the role of PPT1 in mediating synapse functions, implicate molecular pathways in the etiology of NCL and other neurodegenerative diseases, and advance our basic understanding of the purpose of depalmitoylation.
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Affiliation(s)
- Erica L. Gorenberg
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
- Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut, United States of America
| | - Sofia Massaro Tieze
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
- Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut, United States of America
| | - Betül Yücel
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
| | - Helen R. Zhao
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
| | - Vicky Chou
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
| | - Gregory S. Wirak
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
| | - Susumu Tomita
- Departments of Neuroscience and of Cellular and Molecular Physiology, Yale University, New Haven, Connecticut, United States of America
| | - TuKiet T. Lam
- Departments of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Keck MS & Proteomics Resource, WM Keck Biotechnology Resource Laboratory, New Haven, Connecticut, United States of America
| | - Sreeganga S. Chandra
- Departments of Neurology and Neuroscience, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
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2
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Hu L, Tao Z, Wu X. Insights into auto- S-fatty acylation: targets, druggability, and inhibitors. RSC Chem Biol 2021; 2:1567-1579. [PMID: 34977571 PMCID: PMC8637764 DOI: 10.1039/d1cb00115a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/22/2021] [Indexed: 01/21/2023] Open
Abstract
Posttranslational S-fatty acylation (or S-palmitoylation) modulates protein localization and functions, and has been implicated in neurological, metabolic, and infectious diseases, and cancers. Auto-S-fatty acylation involves reactive cysteine residues in the proteins which directly react with fatty acyl-CoA through thioester transfer reactions, and is the first step in some palmitoyl acyltransferase (PAT)-mediated catalysis reactions. In addition, many structural proteins, transcription factors and adaptor proteins might possess such "enzyme-like" activities and undergo auto-S-fatty acylation upon fatty acyl-CoA binding. Auto-S-fatty acylated proteins represent a new class of potential drug targets, which often harbor lipid-binding hydrophobic pockets and reactive cysteine residues, providing potential binding sites for covalent and non-covalent modulators. Therefore, targeting auto-S-fatty acylation could be a promising avenue to pharmacologically intervene in important cellular signaling pathways. Here, we summarize the recent progress in understanding the regulation and functions of auto-S-fatty acylation in cell signaling and diseases. We highlight the druggability of auto-S-fatty acylated proteins, including PATs and other proteins, with potential in silico and rationalized drug design approaches. We also highlight structural analysis and examples of currently known small molecules targeting auto-S-fatty acylation, to gain insights into targeting this class of proteins, and to expand the "druggable" proteome.
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Affiliation(s)
- Lu Hu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School 149, 13th St. Charlestown MA 02129 USA
| | - Zhipeng Tao
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School 149, 13th St. Charlestown MA 02129 USA
| | - Xu Wu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School 149, 13th St. Charlestown MA 02129 USA
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3
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Petropavlovskiy A, Kogut J, Leekha A, Townsend C, Sanders S. A sticky situation: regulation and function of protein palmitoylation with a spotlight on the axon and axon initial segment. Neuronal Signal 2021; 5:NS20210005. [PMID: 34659801 PMCID: PMC8495546 DOI: 10.1042/ns20210005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
In neurons, the axon and axon initial segment (AIS) are critical structures for action potential initiation and propagation. Their formation and function rely on tight compartmentalisation, a process where specific proteins are trafficked to and retained at distinct subcellular locations. One mechanism which regulates protein trafficking and association with lipid membranes is the modification of protein cysteine residues with the 16-carbon palmitic acid, known as S-acylation or palmitoylation. Palmitoylation, akin to phosphorylation, is reversible, with palmitate cycling being mediated by substrate-specific enzymes. Palmitoylation is well-known to be highly prevalent among neuronal proteins and is well studied in the context of the synapse. Comparatively, how palmitoylation regulates trafficking and clustering of axonal and AIS proteins remains less understood. This review provides an overview of the current understanding of the biochemical regulation of palmitoylation, its involvement in various neurological diseases, and the most up-to-date perspective on axonal palmitoylation. Through a palmitoylation analysis of the AIS proteome, we also report that an overwhelming proportion of AIS proteins are likely palmitoylated. Overall, our review and analysis confirm a central role for palmitoylation in the formation and function of the axon and AIS and provide a resource for further exploration of palmitoylation-dependent protein targeting to and function at the AIS.
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Affiliation(s)
- Andrey A. Petropavlovskiy
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Jordan A. Kogut
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Arshia Leekha
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Charlotte A. Townsend
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
| | - Shaun S. Sanders
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph N1G 2W1, Ontario, Canada
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4
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Kerkenberg N, Wachsmuth L, Zhang M, Schettler C, Ponimaskin E, Faber C, Baune BT, Zhang W, Hohoff C. Brain microstructural changes in mice persist in adulthood and are modulated by the palmitoyl acyltransferase ZDHHC7. Eur J Neurosci 2021; 54:5951-5967. [PMID: 34355442 DOI: 10.1111/ejn.15415] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 07/25/2021] [Indexed: 11/30/2022]
Abstract
For a long time, mice have been classified as adults with completely mature brains at 8 weeks of age, but recent research suggests that developmental brain changes occur for up to 6 months. In particular, adolescence coincides with dramatic changes of neuronal structure and function in the brain that influence the connectivity between areas like hippocampus and medial prefrontal cortex (mPFC). Neuronal development and plasticity are regulated in part by the palmitoyl acyltransferase ZDHHC7, which modulates structural connectivity between hippocampus and mPFC. The aim of the current study was to investigate whether developmental changes take place in hippocampus and mPFC microstructure even after 8 weeks of age and whether deficiency of ZDHHC7 impacts such age-dependent alterations. Altogether, 46 mice at 11, 14 or 17 weeks of age with a genetic Zdhhc7 knockout (KO) or wild type (WT) were analysed with neuroimaging and diffusion tensor-based fibre tractography. The hippocampus and mPFC regions were compared regarding fibre metrics, supplemented by volumetric and immunohistological analyses of the hippocampus. In WT animals, we identified age-dependent changes in hippocampal fibre lengths that followed a U-shaped pattern, whereas in mPFC, changes were linear. In Zdhhc7-deficient animals, the fibre statistics were reduced in both regions, whereas the hippocampus volume and the intensities of myelin and neurofilament were higher in 11-week-old KO mice compared to WTs. Our results confirmed ongoing changes of microstructure in mice up to 17 weeks old and demonstrate that deleting the Zdhhc7 gene impairs fibre development, suggesting that palmitoylation is important in this process.
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Affiliation(s)
- Nicole Kerkenberg
- Department of Mental Health, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Lydia Wachsmuth
- Clinic of Radiology, University of Münster, Münster, Germany
| | - Mingyue Zhang
- Department of Mental Health, University of Münster, Münster, Germany
| | | | - Evgeni Ponimaskin
- Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Cornelius Faber
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.,Clinic of Radiology, University of Münster, Münster, Germany
| | - Bernhard T Baune
- Department of Mental Health, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.,Department of Psychiatry, Melbourne Medical School, University of Melbourne, Melbourne, Victoria, Australia.,Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Weiqi Zhang
- Department of Mental Health, University of Münster, Münster, Germany.,Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Christa Hohoff
- Department of Mental Health, University of Münster, Münster, Germany
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Zaręba-Kozioł M, Bartkowiak-Kaczmarek A, Roszkowska M, Bijata K, Figiel I, Halder AK, Kamińska P, Müller FE, Basu S, Zhang W, Ponimaskin E, Włodarczyk J. S-Palmitoylation of Synaptic Proteins as a Novel Mechanism Underlying Sex-Dependent Differences in Neuronal Plasticity. Int J Mol Sci 2021; 22:ijms22126253. [PMID: 34200797 PMCID: PMC8230572 DOI: 10.3390/ijms22126253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 12/12/2022] Open
Abstract
Although sex differences in the brain are prevalent, the knowledge about mechanisms underlying sex-related effects on normal and pathological brain functioning is rather poor. It is known that female and male brains differ in size and connectivity. Moreover, those differences are related to neuronal morphology, synaptic plasticity, and molecular signaling pathways. Among different processes assuring proper synapse functions are posttranslational modifications, and among them, S-palmitoylation (S-PALM) emerges as a crucial mechanism regulating synaptic integrity. Protein S-PALM is governed by a family of palmitoyl acyltransferases, also known as DHHC proteins. Here we focused on the sex-related functional importance of DHHC7 acyltransferase because of its S-PALM action over different synaptic proteins as well as sex steroid receptors. Using the mass spectrometry-based PANIMoni method, we identified sex-dependent differences in the S-PALM of synaptic proteins potentially involved in the regulation of membrane excitability and synaptic transmission as well as in the signaling of proteins involved in the structural plasticity of dendritic spines. To determine a mechanistic source for obtained sex-dependent changes in protein S-PALM, we analyzed synaptoneurosomes isolated from DHHC7-/- (DHHC7KO) female and male mice. Our data showed sex-dependent action of DHHC7 acyltransferase. Furthermore, we revealed that different S-PALM proteins control the same biological processes in male and female synapses.
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Affiliation(s)
- Monika Zaręba-Kozioł
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
- Correspondence: (M.Z.-K.); (J.W.)
| | - Anna Bartkowiak-Kaczmarek
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
| | - Matylda Roszkowska
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
| | - Krystian Bijata
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Izabela Figiel
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
| | - Anup Kumar Halder
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (A.K.H.); (S.B.)
| | - Paulina Kamińska
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
| | - Franziska E. Müller
- Cellular Neurophysiology, Hannover Medical School, Carl-Neuberg Str. 1, 30625 Hannover, Germany; (F.E.M.); (E.P.)
| | - Subhadip Basu
- Department of Computer Science and Engineering, Jadvapur University, Kolkata 700032, India; (A.K.H.); (S.B.)
| | - Weiqi Zhang
- Department of Mental Health, University of Münster, Albert-Schweitzer-Campus 1/A9, 48149 Munster, Germany;
| | - Evgeni Ponimaskin
- Cellular Neurophysiology, Hannover Medical School, Carl-Neuberg Str. 1, 30625 Hannover, Germany; (F.E.M.); (E.P.)
| | - Jakub Włodarczyk
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, Pasteur Str. 3, 02-093 Warsaw, Poland; (A.B.-K.); (M.R.); (K.B.); (I.F.); (P.K.)
- Correspondence: (M.Z.-K.); (J.W.)
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6
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Kerkenberg N, Hohoff C, Zhang M, Lang I, Schettler C, Ponimaskin E, Wachsmuth L, Faber C, Baune BT, Zhang W. Acute stress reveals different impacts in male and female Zdhhc7-deficient mice. Brain Struct Funct 2021; 226:1613-1626. [PMID: 33880616 PMCID: PMC8096773 DOI: 10.1007/s00429-021-02275-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 04/09/2021] [Indexed: 10/25/2022]
Abstract
Numerous processes of neuronal development and synaptic plasticity in the brain rely on the palmitoyl acyltransferase ZDHHC7, as it palmitoylates various synaptic and extrasynaptic proteins such as neural cell adhesion molecule (NCAM) or gamma-aminobutyric acid (GABAA) receptors. In addition, ZDHHC7 palmitoylates sex steroid hormone receptors and is, therefore, indirectly linked to mental disorders that often occur because of or in conjunction with stress. In this work, we investigated how ZDHHC7 affects stress responses in mice. For this purpose, genetically modified mice with a knockout of the Zdhhc7 gene (KO) and wild-type (WT) littermates of both sexes were exposed to acute stressors or control conditions and examined with regard to their behavior, brain microstructure, gene expression, and synaptic plasticity. While no behavioral effects of acute stress were found, we did find that acute stress caused reduced mRNA levels of Esr1 and Esr2 coding for estrogen receptor α and β in the medial prefrontal cortex of male WT and KO mice. Strikingly, after acute stress only male KO mice showed reduced mean fiber lengths of the medioventral hippocampus. Furthermore, Zdhhc7-deficiency impaired synaptic plasticity in mice of both sexes, while acute stress improved it in females, but not in male mice. Taken together, our findings suggest that ZDHHC7 plays a modulatory role in the brain that leads to sex-specific stress responses, possibly due to estrogen receptor-mediated signaling pathways.
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Affiliation(s)
- Nicole Kerkenberg
- Department of Mental Health, University of Münster, Münster, Germany.
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
| | - Christa Hohoff
- Department of Mental Health, University of Münster, Münster, Germany
| | - Mingyue Zhang
- Department of Mental Health, University of Münster, Münster, Germany
| | - Ilona Lang
- Department of Mental Health, University of Münster, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | | | - Evgeni Ponimaskin
- Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Lydia Wachsmuth
- Clinic of Radiology, University of Münster, Münster, Germany
| | - Cornelius Faber
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
- Clinic of Radiology, University of Münster, Münster, Germany
| | - Bernhard T Baune
- Department of Mental Health, University of Münster, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
- Department of Psychiatry, Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia
- Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
| | - Weiqi Zhang
- Department of Mental Health, University of Münster, Münster, Germany.
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
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7
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Ji B, Skup M. Roles of palmitoylation in structural long-term synaptic plasticity. Mol Brain 2021; 14:8. [PMID: 33430908 PMCID: PMC7802216 DOI: 10.1186/s13041-020-00717-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/15/2020] [Indexed: 11/30/2022] Open
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are important cellular mechanisms underlying learning and memory processes. N-Methyl-d-aspartate receptor (NMDAR)-dependent LTP and LTD play especially crucial roles in these functions, and their expression depends on changes in the number and single channel conductance of the major ionotropic glutamate receptor α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) located on the postsynaptic membrane. Structural changes in dendritic spines comprise the morphological platform and support for molecular changes in the execution of synaptic plasticity and memory storage. At the molecular level, spine morphology is directly determined by actin cytoskeleton organization within the spine and indirectly stabilized and consolidated by scaffold proteins at the spine head. Palmitoylation, as a uniquely reversible lipid modification with the ability to regulate protein membrane localization and trafficking, plays significant roles in the structural and functional regulation of LTP and LTD. Altered structural plasticity of dendritic spines is also considered a hallmark of neurodevelopmental disorders, while genetic evidence strongly links abnormal brain function to impaired palmitoylation. Numerous studies have indicated that palmitoylation contributes to morphological spine modifications. In this review, we have gathered data showing that the regulatory proteins that modulate the actin network and scaffold proteins related to AMPAR-mediated neurotransmission also undergo palmitoylation and play roles in modifying spine architecture during structural plasticity.
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Affiliation(s)
- Benjun Ji
- Nencki Institute of Experimental Biology, 02-093, Warsaw, Poland.
| | - Małgorzata Skup
- Nencki Institute of Experimental Biology, 02-093, Warsaw, Poland.
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Shimell JJ, Shah BS, Cain SM, Thouta S, Kuhlmann N, Tatarnikov I, Jovellar DB, Brigidi GS, Kass J, Milnerwood AJ, Snutch TP, Bamji SX. The X-Linked Intellectual Disability Gene Zdhhc9 Is Essential for Dendrite Outgrowth and Inhibitory Synapse Formation. Cell Rep 2020; 29:2422-2437.e8. [PMID: 31747610 DOI: 10.1016/j.celrep.2019.10.065] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/09/2019] [Accepted: 10/13/2019] [Indexed: 11/29/2022] Open
Abstract
Palmitoylation is a reversible post-translational lipid modification that facilitates vesicular transport and subcellular localization of modified proteins. This process is catalyzed by ZDHHC enzymes that are implicated in several neurological and neurodevelopmental disorders. Loss-of-function mutations in ZDHHC9 have been identified in patients with X-linked intellectual disability (XLID) and associated with increased epilepsy risk. Loss of Zdhhc9 function in hippocampal cultures leads to shorter dendritic arbors and fewer inhibitory synapses, altering the ratio of excitatory-to-inhibitory inputs formed onto Zdhhc9-deficient cells. While Zdhhc9 promotes dendrite outgrowth through the palmitoylation of the GTPase Ras, it promotes inhibitory synapse formation through the palmitoylation of another GTPase, TC10. Zdhhc9 knockout mice exhibit seizure-like activity together with increased frequency and amplitude of both spontaneous and miniature excitatory and inhibitory postsynaptic currents. These findings present a plausible mechanism for how the loss of ZDHHC9 function may contribute to XLID and epilepsy.
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Affiliation(s)
- Jordan J Shimell
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Bhavin S Shah
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Stuart M Cain
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Samrat Thouta
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Naila Kuhlmann
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - Igor Tatarnikov
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - D Blair Jovellar
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - G Stefano Brigidi
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Jennifer Kass
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Austen J Milnerwood
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada
| | - Shernaz X Bamji
- Department of Cellular and Physiological Sciences, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
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9
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Pan Y, Xiao Y, Pei Z, Cummins TR. S-Palmitoylation of the sodium channel Nav1.6 regulates its activity and neuronal excitability. J Biol Chem 2020; 295:6151-6164. [PMID: 32161114 DOI: 10.1074/jbc.ra119.012423] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/10/2020] [Indexed: 12/12/2022] Open
Abstract
S-Palmitoylation is a reversible post-translational lipid modification that dynamically regulates protein functions. Voltage-gated sodium channels are subjected to S-palmitoylation and exhibit altered functions in different S-palmitoylation states. Our aim was to investigate whether and how S-palmitoylation regulates Nav1.6 channel function and to identify S-palmitoylation sites that can potentially be pharmacologically targeted. Acyl-biotin exchange assay showed that Nav1.6 is modified by S-palmitoylation in the mouse brain and in a Nav1.6 stable HEK 293 cell line. Using whole-cell voltage clamp, we discovered that enhancing S-palmitoylation with palmitic acid increases Nav1.6 current, whereas blocking S-palmitoylation with 2-bromopalmitate reduces Nav1.6 current and shifts the steady-state inactivation in the hyperpolarizing direction. Three S-palmitoylation sites (Cys1169, Cys1170, and Cys1978) were identified. These sites differentially modulate distinct Nav1.6 properties. Interestingly, Cys1978 is exclusive to Nav1.6 among all Nav isoforms and is evolutionally conserved in Nav1.6 among most species. Cys1978 S-palmitoylation regulates current amplitude uniquely in Nav1.6. Furthermore, we showed that eliminating S-palmitoylation at specific sites alters Nav1.6-mediated excitability in dorsal root ganglion neurons. Therefore, our study reveals S-palmitoylation as a potential isoform-specific mechanism to modulate Nav activity and neuronal excitability in physiological and diseased conditions.
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Affiliation(s)
- Yanling Pan
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Yucheng Xiao
- Department of Biology, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
| | - Zifan Pei
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Theodore R Cummins
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202; Department of Biology, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
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Zareba-Koziol M, Bartkowiak-Kaczmarek A, Figiel I, Krzystyniak A, Wojtowicz T, Bijata M, Wlodarczyk J. Stress-induced Changes in the S-palmitoylation and S-nitrosylation of Synaptic Proteins. Mol Cell Proteomics 2019; 18:1916-1938. [PMID: 31311849 PMCID: PMC6773552 DOI: 10.1074/mcp.ra119.001581] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/12/2019] [Indexed: 11/06/2022] Open
Abstract
The precise regulation of synaptic integrity is critical for neuronal network connectivity and proper brain function. Essential aspects of the activity and localization of synaptic proteins are regulated by posttranslational modifications. S-palmitoylation is a reversible covalent modification of the cysteine with palmitate. It modulates affinity of the protein for cell membranes and membranous compartments. Intracellular palmitoylation dynamics are regulated by crosstalk with other posttranslational modifications, such as S-nitrosylation. S-nitrosylation is a covalent modification of cysteine thiol by nitric oxide and can modulate protein functions. Therefore, simultaneous identification of endogenous site-specific proteomes of both cysteine modifications under certain biological conditions offers new insights into the regulation of functional pathways. Still unclear, however, are the ways in which this crosstalk is affected in brain pathology, such as stress-related disorders. Using a newly developed mass spectrometry-based approach Palmitoylation And Nitrosylation Interplay Monitoring (PANIMoni), we analyzed the endogenous S-palmitoylation and S-nitrosylation of postsynaptic density proteins at the level of specific single cysteine in a mouse model of chronic stress. Among a total of 813 S-PALM and 620 S-NO cysteine sites that were characterized on 465 and 360 proteins, respectively, we sought to identify those that were differentially affected by stress. Our data show involvement of S-palmitoylation and S-nitrosylation crosstalk in the regulation of 122 proteins including receptors, scaffolding proteins, regulatory proteins and cytoskeletal components. Our results suggest that atypical crosstalk between the S-palmitoylation and S-nitrosylation interplay of proteins involved in synaptic transmission, protein localization and regulation of synaptic plasticity might be one of the main events associated with chronic stress disorder, leading to destabilization in synaptic networks.
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Affiliation(s)
- Monika Zareba-Koziol
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland.
| | - Anna Bartkowiak-Kaczmarek
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
| | - Izabela Figiel
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
| | - Adam Krzystyniak
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
| | - Tomasz Wojtowicz
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
| | - Monika Bijata
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland
| | - Jakub Wlodarczyk
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Science, 02-093 Warsaw, Poland.
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Deficiency of the palmitoyl acyltransferase ZDHHC7 impacts brain and behavior of mice in a sex-specific manner. Brain Struct Funct 2019; 224:2213-2230. [PMID: 31183559 DOI: 10.1007/s00429-019-01898-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 05/31/2019] [Indexed: 02/05/2023]
Abstract
The palmitoyl acyltransferase ZDHHC7 belongs to the DHHC family responsible for the covalent attachment of palmitic acid (palmitoylation) to target proteins. Among synaptic proteins, its main targets are sex steroid receptors such as the estrogen receptors. When palmitoylated, these couple to membrane microdomains and elicit non-genomic rapid responses. Such coupling is found particularly in cortico-limbic brain areas which impact structure, function, and behavioral outcomes. Thus far, the functional role of ZDHHC7 has not been investigated in this context. To directly analyze an impact of ZDHHC7 on brain anatomy, microstructure, connectivity, function, and behavior, we generated a mutant mouse in which the Zdhhc7 gene is constitutively inactivated. Male and female Zdhhc7-/- mice were phenotypically compared with wild-type mice using behavioral tests, electrophysiology, protein analyses, and neuroimaging with diffusion tensor-based fiber tractography. Zdhhc7-deficiency impaired excitatory transmission, synaptic plasticity at hippocampal Schaffer collateral CA1 synapses, and hippocampal structural connectivity in both sexes in similar manners. Effects on both sexes but in different manners appeared in medial prefrontal cortical synaptic transmission and in hippocampal microstructures. Finally, Zdhhc7-deficiency affected anxiety-related behaviors exclusively in females. Our data demonstrated the importance of Zdhhc7 for assembling proper brain structure, function, and behavior on a system level in mice in a sex-related manner. Given the prominent role of sex-specificity also in humans and associated mental disorders, Zdhhc7-/- mice might provide a promising model for in-depth investigation of potentially underlying sex-specifically altered mechanisms.
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Meitzen J, Britson KA, Tuomela K, Mermelstein PG. The expression of select genes necessary for membrane-associated estrogen receptor signaling differ by sex in adult rat hippocampus. Steroids 2019; 142:21-27. [PMID: 28962849 PMCID: PMC5874170 DOI: 10.1016/j.steroids.2017.09.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 09/14/2017] [Accepted: 09/22/2017] [Indexed: 12/21/2022]
Abstract
17β-estradiol can rapidly modulate neuron function via membrane estrogen receptors (ERs) in a sex-specific manner. For example, female rat hippocampal neurons express palmitoylated versions of ERα and ERβ that associate with the plasma membrane. These membrane-associated ERs are organized by caveolin proteins into functional signaling microdomains with metabotropic glutamate receptors (mGluRs). ER/mGluR signaling mediates several sex-specific estradiol actions on hippocampal neuron function. An important unanswered question regards the mechanism by which sex-specific membrane-associated ER signaling is generated, especially since it has been previously demonstrated that mGluR action is not sex-specific. One possibility is that the genes necessary for the ER membrane complex are differentially expressed between males and females, including genes that encode ERα and β, caveolin 1 and 3, and/or the palmitoylacyltransferases DHHC-7 and -21. Thus we used qPCR to test the hypothesis that these genes show sex differences in expression in neonatal and adult rat hippocampus. As an additional control we tested the expression of the 20 other DHHC palmitoylacyltransferases with no known connections to ER. In neonatal hippocampus, no sex differences were detected in gene expression. In adult hippocampus, the genes that encode caveolin 1 and DHHC-7 showed decreased expression in females compared to males. Thus, select genes differ by sex at specific developmental stages, arguing for a more nuanced model than simple widespread perinatal emergence of sex differences in all genes enabling sex-specific estradiol action. These findings enable the generation of new hypotheses regarding the mechanisms by which sex differences in membrane-associated ER signaling are programmed.
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Affiliation(s)
- John Meitzen
- Dept. of Biological Sciences, North Carolina State University, Raleigh, NC, United States; W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, United States; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States; Comparative Medicine Institute, North Carolina State University, Raleigh, NC, United States.
| | - Kyla A Britson
- Cellular and Molecular Medicine Graduate Program, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Krista Tuomela
- Medical College of Wisconsin, Milwaukee, WI, United States
| | - Paul G Mermelstein
- Dept. of Neuroscience, University of Minnesota, Minneapolis, MN, United States
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13
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Sapoń K, Janas T, Sikorski AF, Janas T. Polysialic acid chains exhibit enhanced affinity for ordered regions of membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:245-255. [DOI: 10.1016/j.bbamem.2018.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/25/2018] [Accepted: 07/19/2018] [Indexed: 12/28/2022]
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14
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Kathayat RS, Dickinson BC. Measuring S-Depalmitoylation Activity In Vitro and In Live Cells with Fluorescent Probes. Methods Mol Biol 2019; 2009:99-109. [PMID: 31152398 PMCID: PMC7240838 DOI: 10.1007/978-1-4939-9532-5_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
S-palmitoylation is a reversible lipid posttranslational modification (PTM) that can mediate protein localization, trafficking, interaction with membranes, and a host of other biophysical characteristics. Over the past decade, a suite of chemoproteomic strategies have uncovered the breadth of S-palmitoylation, revealing widespread susceptibility to modification by this PTM throughout the human proteome. A focal point of research toward understanding the role of S-palmitoylation in varied cellular processes has focused on understanding how "writer" and "eraser" proteins function together to control the levels of S-palmitoylation of target proteins. The spatial and temporal regulation of S-palmitoylation by its "erasers"-acyl protein thioesterases (APTs)-is not fully understood. Tools which enable monitoring of the activity levels of the APTs in real-time in live cells illuminate how spatial control of these enzymes redecorate the lipidation state of the local proteome. To this end, we have developed fluorescence-based depalmitoylation probes (DPPs), which report S-depalmitoylase activity in live cells. Using DPPs, we have demonstrated that S-depalmitoylase activity changes in response to growth factor stimulation, unveiling potential regulation of cell growth and metabolism by APTs. Additionally, we recently discovered APTs in mitochondria using targeted DPPs, indicating new roles for S-depalmitoylation in this critical cellular compartment. Here, we present detailed protocols on how to carry out in vitro S-depalmitoylase activity assays and live cell fluorescence imaging employing the growing DPP toolbox.
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Golgi-specific DHHC type zinc finger protein is decreased in neurons of intractable epilepsy patients and pentylenetetrazole-kindled rats. Neuroreport 2018; 29:1157-1165. [PMID: 29994811 DOI: 10.1097/wnr.0000000000001088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Golgi-specific DHHC type zinc finger protein (GODZ) is a member of the DHHC protein family, and its enzymatic activity is regulated by fibroblast growth factor or Src kinase-mediated tyrosine phosphorylation. In cultured neurons, GODZ affects the numbers of calcium ions channels, α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors, N-methy-D-aspartate receptors, and γ-aminobutyric acid A receptors on postsynaptic membrane by palmitoylation, thus modulating synaptic plasticity. As the change in synaptic plasticity plays a role in epilepsy, GODZ may play roles in epilepsy. However, the expression of GODZ has never been investigated in brain tissues in vivo, and its change during epilepsy is still unclear. In this study, the cellular distribution of GODZ in brain tissues of both patients and rats was determined using double-labeled immunofluorescence and the levels of GODZ protein and mRNA among intractable epilepsy patients, pentylenetetrazole (PTZ)-kindled rats, and controls were measured using immunohistochemistry, Western blot, and real-time quantitative polymerase chain reaction. GODZ expression was identified on cytomembranes and in the cytoplasm of neurons in the temporal neocortex of intractable epilepsy patients and in the hippocampus and the adjacent temporal cortex of PTZ-kindled rats, but not in astrocytes. Decreased GODZ protein and mRNA were identified in brain tissues of intractable epilepsy patients and PTZ-kindled rats compared with the controls. In conclusion, GODZ is expressed in neurons, but not astrocytes, and epilepsy may reduce the protein and mRNA levels of GODZ, indicating a possible role of GODZ in the pathogenesis or the pathophysiology of epilepsy.
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Chen B, Sun Y, Niu J, Jarugumilli GK, Wu X. Protein Lipidation in Cell Signaling and Diseases: Function, Regulation, and Therapeutic Opportunities. Cell Chem Biol 2018; 25:817-831. [PMID: 29861273 PMCID: PMC6054547 DOI: 10.1016/j.chembiol.2018.05.003] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/06/2017] [Accepted: 05/01/2018] [Indexed: 01/08/2023]
Abstract
Protein lipidation is an important co- or posttranslational modification in which lipid moieties are covalently attached to proteins. Lipidation markedly increases the hydrophobicity of proteins, resulting in changes to their conformation, stability, membrane association, localization, trafficking, and binding affinity to their co-factors. Various lipids and lipid metabolites serve as protein lipidation moieties. The intracellular concentrations of these lipids and their derivatives are tightly regulated by cellular metabolism. Therefore, protein lipidation links the output of cellular metabolism to the regulation of protein function. Importantly, deregulation of protein lipidation has been linked to various diseases, including neurological disorders, metabolic diseases, and cancers. In this review, we highlight recent progress in our understanding of protein lipidation, in particular, S-palmitoylation and lysine fatty acylation, and we describe the importance of these modifications for protein regulation, cell signaling, and diseases. We further highlight opportunities and new strategies for targeting protein lipidation for therapeutic applications.
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Affiliation(s)
- Baoen Chen
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, 149, 13th St., Charlestown, MA 02129, USA
| | - Yang Sun
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, 149, 13th St., Charlestown, MA 02129, USA
| | - Jixiao Niu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, 149, 13th St., Charlestown, MA 02129, USA
| | - Gopala K Jarugumilli
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, 149, 13th St., Charlestown, MA 02129, USA
| | - Xu Wu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, 149, 13th St., Charlestown, MA 02129, USA.
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17
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Palmitoylation as a Functional Regulator of Neurotransmitter Receptors. Neural Plast 2018; 2018:5701348. [PMID: 29849559 PMCID: PMC5903346 DOI: 10.1155/2018/5701348] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 01/29/2018] [Indexed: 12/11/2022] Open
Abstract
The majority of neuronal proteins involved in cellular signaling undergo different posttranslational modifications significantly affecting their functions. One of these modifications is a covalent attachment of a 16-C palmitic acid to one or more cysteine residues (S-palmitoylation) within the target protein. Palmitoylation is a reversible modification, and repeated cycles of palmitoylation/depalmitoylation might be critically involved in the regulation of multiple signaling processes. Palmitoylation also represents a common posttranslational modification of the neurotransmitter receptors, including G protein-coupled receptors (GPCRs) and ligand-gated ion channels (LICs). From the functional point of view, palmitoylation affects a wide span of neurotransmitter receptors activities including their trafficking, sorting, stability, residence lifetime at the cell surface, endocytosis, recycling, and synaptic clustering. This review summarizes the current knowledge on the palmitoylation of neurotransmitter receptors and its role in the regulation of receptors functions as well as in the control of different kinds of physiological and pathological behavior.
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18
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Ephexin1 Is Required for Eph-Mediated Limb Trajectory of Spinal Motor Axons. J Neurosci 2018; 38:2043-2056. [PMID: 29363583 DOI: 10.1523/jneurosci.2257-17.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 01/10/2018] [Accepted: 01/15/2018] [Indexed: 11/21/2022] Open
Abstract
The precise assembly of a functional nervous system relies on the guided migration of axonal growth cones, which is made possible by signals transmitted to the cytoskeleton by cell surface-expressed guidance receptors. We investigated the function of ephexin1, a Rho guanine nucleotide exchange factor, as an essential growth-cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show that ephexin1 is expressed in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb. Ephexin1 loss of function and gain of function using in ovo electroporation in chick LMC neurons, of either sex, perturbed LMC axon trajectory selection, demonstrating an essential role of ephexin1 in motor axon guidance. In addition, ephexin1 loss in mice of either sex led to LMC axon trajectory selection errors. We also show that ephexin1 knockdown attenuates the growth preference of LMC neurites against ephrins in vitro and Eph receptor-mediated retargeting of LMC axons in vivo, suggesting that ephexin1 is required in Eph-mediated LMC motor axon guidance. Finally, both ephexin1 knockdown and ectopic expression of nonphosphorylatable ephexin1 mutant attenuated the retargeting of LMC axons caused by Src overexpression, implicating ephexin1 as an Src target in Eph signal relay in this context. In summary, our findings demonstrate that ephexin1 is essential for motor axon guidance and suggest an important role in relaying ephrin:Eph signals that mediate motor axon trajectory selection.SIGNIFICANCE STATEMENT The proper development of functioning neural circuits requires precise nerve connections among neurons or between neurons and their muscle targets. The Eph tyrosine kinase receptors expressed in neurons are important in many contexts during neural-circuit formation, such as axon outgrowth, axon guidance, and synaptic formation, and have been suggested to be involved in neurodegenerative disorders, including amyotrophic lateral sclerosis and Alzheimer's disease. To dissect the mechanism of Eph signal relay, we studied ephexin1 gain of function and loss of function and found ephexin1 essential for the development of limb nerves toward their muscle targets, concluding that it functions as an intermediary to relay Eph signaling in this context. Our work could thus shed new light on the molecular mechanisms controlling neuromuscular connectivity during embryonic development.
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19
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Qiu T, Kathayat RS, Cao Y, Beck MW, Dickinson BC. A Fluorescent Probe with Improved Water Solubility Permits the Analysis of Protein S-Depalmitoylation Activity in Live Cells. Biochemistry 2018; 57:221-225. [PMID: 29023093 PMCID: PMC5823605 DOI: 10.1021/acs.biochem.7b00835] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
S-Palmitoylation is an abundant lipid post-translational modification that is dynamically installed on and removed from target proteins to regulate their activity and cellular localization. A dearth of tools for studying the activities and regulation of protein S-depalmitoylases, thioesterase "erasers" of protein cysteine S-palmitoylation, has contributed to an incomplete understanding of the role of dynamic S-palmitoylation in regulating proteome lipidation. Recently, we developed "depalmitoylation probes" (DPPs), small molecule probes that become fluorescent upon S-depalmitoylase enzymatic activity. To be suitable for application in live cells, the first-generation DPPs relied on a shorter lipid substrate (C8 vs naturally occurring C16), which enhanced solubility and cell permeability. However, the use of an unnatural lipid substrate on the probes potentially limits the utility of the approach. Herein, we present a new member of the DPP family, DPP-5, which features an anionic carboxylate functional group that increases the probe water solubility. The enhanced water solubility of DPP-5 permits the use of a natural, palmitoylated substrate (C16), rather than a surrogate lipid. We show that DPP-5 is capable of monitoring endogenous S-depalmitoylases in live mammalian cells and that it can reveal changes in S-depalmitoylation levels due to lipid stress. DPP-5 should prove to be a useful new tool for probing the regulation of proteome lipidation through dynamic S-depalmitoylation.
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Affiliation(s)
- Tian Qiu
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
| | - Rahul S. Kathayat
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
| | - Yang Cao
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
| | - Michael W. Beck
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
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20
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Beck MW, Kathayat RS, Cham CM, Chang EB, Dickinson BC. Michael addition-based probes for ratiometric fluorescence imaging of protein S-depalmitoylases in live cells and tissues. Chem Sci 2017; 8:7588-7592. [PMID: 29568422 PMCID: PMC5848818 DOI: 10.1039/c7sc02805a] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/09/2017] [Indexed: 12/31/2022] Open
Abstract
The reversible modification of cysteine residues through thioester formation with palmitate (protein S-palmitoylation) is a prevalent chemical modification that regulates the function, localization, and stability of many proteins. Current methods for monitoring the "erasers" of S-palmitoylation, acyl-protein thioesterases (APTs), rely on destructive proteomic methods or "turn-on" probes, precluding deployment in heterogeneous samples such as primary tissues. To address these challenges, we present the design, synthesis, and biological evaluation of Ratiometric Depalmitoylation Probes (RDPs). RDPs respond to APTs with a robust ratiometric change in fluorescent signal both in vitro and in live cells. Moreover, RDPs can monitor endogenous APT activities in heterogeneous primary human tissues such as colon organoids, presaging the utility of these molecules in uncovering novel roles for APTs in metabolic regulation.
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Affiliation(s)
- Michael W Beck
- Department of Chemistry , The University of Chicago , 5801 South Ellis Avenue , Chicago , Illinois 60637 , USA .
| | - Rahul S Kathayat
- Department of Chemistry , The University of Chicago , 5801 South Ellis Avenue , Chicago , Illinois 60637 , USA .
| | - Candace M Cham
- Department of Medicine , The University of Chicago , 5801 South Ellis Avenue , Chicago , Illinois 60637 , USA
| | - Eugene B Chang
- Department of Medicine , The University of Chicago , 5801 South Ellis Avenue , Chicago , Illinois 60637 , USA
| | - Bryan C Dickinson
- Department of Chemistry , The University of Chicago , 5801 South Ellis Avenue , Chicago , Illinois 60637 , USA .
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21
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Globa AK, Bamji SX. Protein palmitoylation in the development and plasticity of neuronal connections. Curr Opin Neurobiol 2017; 45:210-220. [PMID: 28366531 DOI: 10.1016/j.conb.2017.02.016] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/19/2017] [Accepted: 02/28/2017] [Indexed: 01/01/2023]
Abstract
Protein palmitoylation, or the reversible addition of the fatty acid, palmitate, onto substrate proteins, can impact the structure and stability of proteins as well as regulate protein-protein interactions and the trafficking and localization of proteins to cell membranes. This posttranslational modification is mediated by palmitoyl-acyltransferases, consisting of a family of 23 zDHHC proteins in mammals. This review focuses on the subcellular distribution of zDHHC proteins within the neuron and the regulation of zDHHC trafficking and function by synaptic activity. We review recent studies identifying actin binding proteins, cell adhesion molecules and synaptic scaffolding proteins as targets of palmitoylation, and examine the implications of activity-mediated palmitoylation in the establishment and plasticity of neuronal connections.
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Affiliation(s)
- Andrea K Globa
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Shernaz X Bamji
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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22
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Kathayat RS, Elvira PD, Dickinson BC. A fluorescent probe for cysteine depalmitoylation reveals dynamic APT signaling. Nat Chem Biol 2017; 13:150-152. [PMID: 27992880 PMCID: PMC5247352 DOI: 10.1038/nchembio.2262] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 11/02/2016] [Indexed: 12/25/2022]
Abstract
Hundreds of human proteins are modified by reversible palmitoylation of cysteine residues (S-palmitoylation), but the regulation of depalmitoylation is poorly understood. Here, we develop 'depalmitoylation probes' (DPPs), small-molecule fluorophores, to monitor the endogenous activity levels of 'erasers' of S-palmitoylation, acylprotein thioesterases (APTs). Live-cell analysis with DPPs reveals rapid growth-factor-mediated inhibition of the depalmitoylation activity of APTs, exposing a novel regulatory mechanism of dynamic lipid signaling.
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Affiliation(s)
- Rahul S. Kathayat
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
| | - Pablo D. Elvira
- Department of Chemistry, The University of Chicago, Chicago, IL 60637
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23
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Li Y, Qi B. Progress toward Understanding Protein S-acylation: Prospective in Plants. FRONTIERS IN PLANT SCIENCE 2017; 8:346. [PMID: 28392791 PMCID: PMC5364179 DOI: 10.3389/fpls.2017.00346] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/28/2017] [Indexed: 05/02/2023]
Abstract
S-acylation, also known as S-palmitoylation or palmitoylation, is a reversible post-translational lipid modification in which long chain fatty acid, usually the 16-carbon palmitate, covalently attaches to a cysteine residue(s) throughout the protein via a thioester bond. It is involved in an array of important biological processes during growth and development, reproduction and stress responses in plant. S-acylation is a ubiquitous mechanism in eukaryotes catalyzed by a family of enzymes called Protein S-Acyl Transferases (PATs). Since the discovery of the first PAT in yeast in 2002 research in S-acylation has accelerated in the mammalian system and followed by in plant. However, it is still a difficult field to study due to the large number of PATs and even larger number of putative S-acylated substrate proteins they modify in each genome. This is coupled with drawbacks in the techniques used to study S-acylation, leading to the slower progress in this field compared to protein phosphorylation, for example. In this review we will summarize the discoveries made so far based on knowledge learnt from the characterization of protein S-acyltransferases and the S-acylated proteins, the interaction mechanisms between PAT and its specific substrate protein(s) in yeast and mammals. Research in protein S-acylation and PATs in plants will also be covered although this area is currently less well studied in yeast and mammalian systems.
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24
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Cho E, Park M. Palmitoylation in Alzheimers disease and other neurodegenerative diseases. Pharmacol Res 2016; 111:133-151. [DOI: 10.1016/j.phrs.2016.06.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/07/2016] [Accepted: 06/08/2016] [Indexed: 12/13/2022]
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25
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ZDHHC3 Tyrosine Phosphorylation Regulates Neural Cell Adhesion Molecule Palmitoylation. Mol Cell Biol 2016; 36:2208-25. [PMID: 27247265 DOI: 10.1128/mcb.00144-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023] Open
Abstract
The neural cell adhesion molecule (NCAM) mediates cell-cell and cell-matrix adhesion. It is broadly expressed in the nervous system and regulates neurite outgrowth, synaptogenesis, and synaptic plasticity. Previous in vitro studies revealed that palmitoylation of NCAM is required for fibroblast growth factor 2 (FGF2)-stimulated neurite outgrowth and identified the zinc finger DHHC (Asp-His-His-Cys)-containing proteins ZDHHC3 and ZDHHC7 as specific NCAM-palmitoylating enzymes. Here, we verified that FGF2 controlled NCAM palmitoylation in vivo and investigated molecular mechanisms regulating NCAM palmitoylation by ZDHHC3. Experiments with overexpression and pharmacological inhibition of FGF receptor (FGFR) and Src revealed that these kinases control tyrosine phosphorylation of ZDHHC3 and that ZDHHC3 is phosphorylated by endogenously expressed FGFR and Src proteins. By site-directed mutagenesis, we found that Tyr18 is an FGFR1-specific ZDHHC3 phosphorylation site, while Tyr295 and Tyr297 are specifically phosphorylated by Src kinase in cell-based and cell-free assays. Abrogation of tyrosine phosphorylation increased ZDHHC3 autopalmitoylation, enhanced interaction with NCAM, and upregulated NCAM palmitoylation. Expression of ZDHHC3 with tyrosine mutated in cultured hippocampal neurons promoted neurite outgrowth. Our findings for the first time highlight that FGFR- and Src-mediated tyrosine phosphorylation of ZDHHC3 modulates ZDHHC3 enzymatic activity and plays a role in neuronal morphogenesis.
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Shi W, Chen X, Wang F, Gao M, Yang Y, Du Z, Wang C, Yao Y, He K, Hao A. ZDHHC16 modulates FGF/ERK dependent proliferation of neural stem/progenitor cells in the zebrafish telencephalon. Dev Neurobiol 2016; 76:1014-28. [PMID: 26663717 DOI: 10.1002/dneu.22372] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/24/2015] [Accepted: 12/08/2015] [Indexed: 12/22/2022]
Abstract
In vertebrates, neural stem/progenitor cells (NSPCs) maintenance is critical for nervous system development and homeostasis. However, the molecular mechanisms underlying the maintenance of NSPCs have not been fully elucidated. Here, we demonstrated that zebrafish ZDHHC16, a DHHC encoding protein, which was related to protein palmitoylation after translation, was expressed in the developing forebrain, and especially in the telencephalon. Loss- and gain-of-function studies showed that ZDHHC16 played a crucial role in the regualtion of NSPCs proliferation during zebrafish telencephalic development, via a mechanism dependent on its palmitoyltransferase activity. Further analyses showed that the inhibition of ZDHHC16 led to inactivation of the FGF/ERK signaling pathway during telencephalic NSPCs proliferation and maintenance. Taken together, our results suggest that ZDHHC16 activity is essential for early NSPCs proliferation where it acts to activate the FGF/ERK network, allowing for the initiation of proliferation -regulated gene expression programs. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1014-1028, 2016.
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Affiliation(s)
- Wei Shi
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
| | - Xueran Chen
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Anhui, 230031, People's Republic of China
| | - Fen Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
| | - Ming Gao
- Reproductive Medical Center of Shandong University, Shandong University School of Medicine, Shandong, 250012, People's Republic of China
| | - Yang Yang
- Infertility Center, Qilu Hospital, Shandong University School of Medicine, Shandong, 250012, People's Republic of China
| | - Zhaoxia Du
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
| | - Chen Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
| | - Yao Yao
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
| | - Kun He
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
| | - Aijun Hao
- Key Laboratory of the Ministry of Education for Experimental Teratology; Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, PR China
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Wang F, Chen X, Shi W, Yao L, Gao M, Yang Y, Hao A. Zdhhc15b Regulates Differentiation of Diencephalic Dopaminergic Neurons in zebrafish. J Cell Biochem 2015; 116:2980-91. [DOI: 10.1002/jcb.25256] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 06/09/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Fen Wang
- KeyLaboratory of the Ministry of Education; Shandong Provincial Key Laboratory of Mental Department of Histology Embryology; Shandong University School of Medicine; No. 44 Wenhua Xi Road; Jinan Shandong 250012 PR China
| | - Xueran Chen
- Center of Medical Physics and Technology; Hefei Institutes of Physical Science, Chinese Academy of Sciences; No. 350, Shushan Hu Road Hefei AnHui 230031 PR China
| | - Wei Shi
- KeyLaboratory of the Ministry of Education; Shandong Provincial Key Laboratory of Mental Department of Histology Embryology; Shandong University School of Medicine; No. 44 Wenhua Xi Road; Jinan Shandong 250012 PR China
| | - Linli Yao
- KeyLaboratory of the Ministry of Education; Shandong Provincial Key Laboratory of Mental Department of Histology Embryology; Shandong University School of Medicine; No. 44 Wenhua Xi Road; Jinan Shandong 250012 PR China
| | - Ming Gao
- Reproductive medical center of Shandong University; Shandong University School of Medicine; No. 44, Wenhua Xi Road; Jinan Shandong 250012 PR China
| | - Yang Yang
- Infertility Center, Qilu Hospital; Shandong University School of Medicine; No. 44, Wenhua Xi Road; Jinan Shandong 250012 PR China
| | - Aijun Hao
- KeyLaboratory of the Ministry of Education; Shandong Provincial Key Laboratory of Mental Department of Histology Embryology; Shandong University School of Medicine; No. 44 Wenhua Xi Road; Jinan Shandong 250012 PR China
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28
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Wang C, Chen X, Shi W, Wang F, Du Z, Li X, Yao Y, Liu T, Shao T, Li G, Hao A. 2-Bromopalmitate impairs neural stem/progenitor cell proliferation, promotes cell apoptosis and induces malformation in zebrafish embryonic brain. Neurotoxicol Teratol 2015; 50:53-63. [DOI: 10.1016/j.ntt.2015.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/15/2015] [Accepted: 06/01/2015] [Indexed: 01/13/2023]
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Protein S-palmitoylation and cancer. Biochim Biophys Acta Rev Cancer 2015; 1856:107-20. [PMID: 26112306 DOI: 10.1016/j.bbcan.2015.06.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/16/2015] [Accepted: 06/21/2015] [Indexed: 12/16/2022]
Abstract
Protein S-palmitoylation is a reversible posttranslational modification of proteins with fatty acids, an enzymatic process driven by a recently discovered family of protein acyltransferases (PATs) that are defined by a conserved catalytic domain characterized by a DHHC sequence motif. Protein S-palmitoylation has a prominent role in regulating protein location, trafficking and function. Recent studies of DHHC PATs and their functional effects have demonstrated that their dysregulation is associated with human diseases, including schizophrenia, X-linked mental retardation, and Huntington's Disease. A growing number of reports indicate an important role for DHHC proteins and their substrates in tumorigenesis. Whereas DHHC PATs comprise a family of 23 enzymes in humans, a smaller number of enzymes that remove palmitate have been identified and characterized as potential therapeutic targets. Here we review current knowledge of the enzymes that mediate reversible palmitoylation and their cancer-associated substrates and discuss potential therapeutic applications.
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Abstract
Protein S-acylation, the only fully reversible posttranslational lipid modification of proteins, is emerging as a ubiquitous mechanism to control the properties and function of a diverse array of proteins and consequently physiological processes. S-acylation results from the enzymatic addition of long-chain lipids, most typically palmitate, onto intracellular cysteine residues of soluble and transmembrane proteins via a labile thioester linkage. Addition of lipid results in increases in protein hydrophobicity that can impact on protein structure, assembly, maturation, trafficking, and function. The recent explosion in global S-acylation (palmitoyl) proteomic profiling as a result of improved biochemical tools to assay S-acylation, in conjunction with the recent identification of enzymes that control protein S-acylation and de-acylation, has opened a new vista into the physiological function of S-acylation. This review introduces key features of S-acylation and tools to interrogate this process, and highlights the eclectic array of proteins regulated including membrane receptors, ion channels and transporters, enzymes and kinases, signaling adapters and chaperones, cell adhesion, and structural proteins. We highlight recent findings correlating disruption of S-acylation to pathophysiology and disease and discuss some of the major challenges and opportunities in this rapidly expanding field.
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Affiliation(s)
- Luke H Chamberlain
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Strathclyde University, Glasgow, United Kingdom; and Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael J Shipston
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Strathclyde University, Glasgow, United Kingdom; and Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom
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31
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Blaskovic S, Adibekian A, Blanc M, van der Goot GF. Mechanistic effects of protein palmitoylation and the cellular consequences thereof. Chem Phys Lipids 2014; 180:44-52. [PMID: 24534427 DOI: 10.1016/j.chemphyslip.2014.02.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/31/2014] [Accepted: 02/03/2014] [Indexed: 12/21/2022]
Abstract
S-palmitoylation involves the attachment of a 16-carbon long fatty acid chain to the cysteine residues of proteins. The process is enzymatic and dynamic with DHHC enzymes mediating palmitoylation and acyl-protein thioesterases reverting the reaction. Proteins that undergo this modification span almost all cellular functions. While the increase in hydrophobicity generated by palmitoylation has the obvious consequence of triggering membrane association, the effects on transmembrane proteins are less intuitive and span a vast range. We review here the current knowledge on palmitoylating and depalmitoylating enzymes, the methods that allow the study of this lipid modification and which drugs can affect it, and finally we focus on four cellular processes for which recent studies reveal an involvement of palmitoylation: endocytosis, reproduction and cell growth, fat and sugar homeostasis and signal transduction at the synapse.
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Affiliation(s)
- Sanja Blaskovic
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Alexander Adibekian
- Department of Organic Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Mathieu Blanc
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Gisou F van der Goot
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland.
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32
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Meitzen J, Luoma JI, Boulware MI, Hedges VL, Peterson BM, Tuomela K, Britson KA, Mermelstein PG. Palmitoylation of estrogen receptors is essential for neuronal membrane signaling. Endocrinology 2013; 154:4293-304. [PMID: 24008343 PMCID: PMC3800757 DOI: 10.1210/en.2013-1172] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In addition to activating nuclear estrogen receptor signaling, 17β-estradiol can also regulate neuronal function via surface membrane receptors. In various brain regions, these actions are mediated by the direct association of estrogen receptors (ERs) activating metabotropic glutamate receptors (mGluRs). These ER/mGluR signaling partners are organized into discrete functional microdomains via caveolin proteins. A central question that remains concerns the underlying mechanism by which these subpopulations of ERs are targeted to the surface membrane. One candidate mechanism is S-palmitoylation, a posttranscriptional modification that affects the subcellular distribution and function of the modified protein, including promoting localization to membranes. Here we test for the role of palmitoylation and the necessity of specific palmitoylacyltransferase proteins in neuronal membrane ER action. In hippocampal neurons, pharmacological inhibition of palmitoylation eliminated 17β-estradiol-mediated phosphorylation of cAMP response element-binding protein, a process dependent on surface membrane ERs. In addition, mutation of the palmitoylation site on estrogen receptor (ER) α blocks ERα-mediated cAMP response element-binding protein phosphorylation. Similar results were obtained after mutation of the palmitoylation site on ERβ. Importantly, mutation of either ERα or ERβ did not affect the ability of the reciprocal ER to signal at the membrane. In contrast, membrane ERα and ERβ signaling were both dependent on the expression of the palmitoylacyltransferase proteins DHHC-7 and DHHC-21. Neither mGluR activity nor caveolin or ER expression was affected by knockdown of DHHC-7 and DHHC-21. These data collectively suggest discrete mechanisms that regulate specific isoform or global membrane ER signaling in neurons separate from mGluR activity or nuclear ER function.
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Affiliation(s)
- John Meitzen
- PhD, Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University, 127 David Clark Laboratories, Campus Box 7617, Raleigh, North Carolina 27695.
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Neural cell adhesion molecule-mediated Fyn activation promotes GABAergic synapse maturation in postnatal mouse cortex. J Neurosci 2013; 33:5957-68. [PMID: 23554477 DOI: 10.1523/jneurosci.1306-12.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
GABAergic basket interneurons form perisomatic synapses, which are essential for regulating neural networks, and their alterations are linked to various cognitive dysfunction. Maturation of basket synapses in postnatal cortex is activity dependent. In particular, activity-dependent downregulation of polysialiac acid carried by the neural cell adhesion molecule (NCAM) regulates the timing of their maturation. Whether and how NCAM per se affects GABAergic synapse development is unknown. Using single-cell genetics to knock out NCAM in individual basket interneurons in mouse cortical slice cultures, at specific developmental time periods, we found that NCAM loss during perisomatic synapse formation impairs the process of basket cell axonal branching and bouton formation. However, loss of NCAM once the synapses are already formed did not show any effect. We further show that NCAM120 and NCAM140, but not the NCAM180 isoform, rescue the phenotype. Finally, we demonstrate that a dominant-negative form of Fyn kinase mimics, whereas a constitutively active form of Fyn kinase rescues, the effects of NCAM knockdown. Altogether, our data suggest that NCAM120/NCAM140-mediated Fyn activation promotes GABAergic synapse maturation in postnatal cortex.
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34
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Blaskovic S, Blanc M, van der Goot FG. What does S-palmitoylation do to membrane proteins? FEBS J 2013; 280:2766-74. [PMID: 23551889 DOI: 10.1111/febs.12263] [Citation(s) in RCA: 182] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 03/20/2013] [Accepted: 03/25/2013] [Indexed: 12/19/2022]
Abstract
S-palmitoylation is post-translational modification, which consists in the addition of a C16 acyl chain to cytosolic cysteines and which is unique amongst lipid modifications in that it is reversible. It can thus, like phosphorylation or ubiquitination, act as a switch. While palmitoylation of soluble proteins allows them to interact with membranes, the consequences of palmitoylation for transmembrane proteins are more enigmatic. We briefly review the current knowledge regarding the enzymes responsible for palmitate addition and removal. We then describe various observed consequences of membrane protein palmitoylation. We propose that the direct effects of palmitoylation on transmembrane proteins, however, might be limited to four non-mutually exclusive mechanistic consequences: alterations in the conformation of transmembrane domains, association with specific membrane domains, controlled interactions with other proteins and controlled interplay with other post-translational modifications.
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Affiliation(s)
- Sanja Blaskovic
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Switzerland
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35
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Verslegers M, Lemmens K, Van Hove I, Moons L. Matrix metalloproteinase-2 and -9 as promising benefactors in development, plasticity and repair of the nervous system. Prog Neurobiol 2013; 105:60-78. [PMID: 23567503 DOI: 10.1016/j.pneurobio.2013.03.004] [Citation(s) in RCA: 310] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 03/01/2013] [Accepted: 03/28/2013] [Indexed: 11/16/2022]
Abstract
It has been 50 years since Gross and Lapiere discovered collagenolytic activity during tadpole tail metamorphosis, which was later on revealed as MMP-1, the founding member of the matrix metalloproteinases (MMPs). Currently, MMPs constitute a large group of endoproteases that are not only able to cleave all protein components of the extracellular matrix, but also to activate or inactivate many other signaling molecules, such as receptors, adhesion molecules and growth factors. Elevated MMP levels are associated with an increasing number of injuries and disorders, such as cancer, inflammation and auto-immune diseases. Yet, MMP upregulation has also been implicated in many physiological functions such as embryonic development, wound healing and angiogenesis and therefore, these proteinases are considered to be crucial mediators in many biological processes. Over the past decennia, MMP research has gained considerable attention in several pathologies, most prominently in the field of cancer metastasis, and more recent investigations also focus on the nervous system, with a striking emphasis on the gelatinases, MMP-2 and MMP-9. Unfortunately, the contribution of these gelatinases to neuropathological disorders, like multiple sclerosis and Alzheimer's disease, has overshadowed their potential as modulators of fundamental nervous system functions. Within this review, we wish to highlight the currently known or suggested actions of MMP-2 and MMP-9 in the developing and adult nervous system and their potential to improve repair or regeneration after nervous system injury.
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Affiliation(s)
- Mieke Verslegers
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
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36
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The neural cell adhesion molecule (NCAM) associates with and signals through p21-activated kinase 1 (Pak1). J Neurosci 2013; 33:790-803. [PMID: 23303955 DOI: 10.1523/jneurosci.1238-12.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The Neural cell adhesion molecule (NCAM) plays an important role in regulation of nervous system development. To expand our understanding of the molecular mechanisms via which NCAM influences differentiation of neurons, we used a yeast two-hybrid screening to search for new binding partners of NCAM and identified p21-activated kinase 1 (Pak1). We show that NCAM interacts with Pak1 in growth cones of neurons. The autophosphorylation and activity of Pak1 were enhanced when isolated growth cones were incubated with NCAM function triggering antibodies, which mimic the interaction between NCAM and its extracellular ligands. The association of Pak1 with cell membranes, the efficiency of Pak1 binding to its activators, and Pak1 activity were inhibited in brains of NCAM-deficient mice. NCAM-dependent Pak1 activation was abolished after lipid raft disruption, suggesting that NCAM promotes Pak1 activation in the lipid raft environment. Phosphorylation of the downstream Pak1 effectors LIMK1 and cofilin was reduced in growth cones from NCAM-deficient neurons, which was accompanied by decreased levels of filamentous actin and inhibited filopodium mobility in the growth cones. Dominant-negative Pak1 inhibited and constitutively active Pak1 enhanced the ability of neurons to increase neurite outgrowth in response to the extracellular ligands of NCAM. Our combined observations thus indicate that NCAM activates Pak1 to drive actin polymerization to promote neuronal differentiation.
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37
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Glial cell line-derived neurotrophic factor (GDNF) induces neuritogenesis in the cochlear spiral ganglion via neural cell adhesion molecule (NCAM). Mol Cell Neurosci 2012; 54:30-43. [PMID: 23262364 DOI: 10.1016/j.mcn.2012.12.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 11/24/2012] [Accepted: 12/12/2012] [Indexed: 11/21/2022] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) increases survival and neurite extension of spiral ganglion neurons (SGNs), the primary neurons of the auditory system, via yet unknown signaling mechanisms. In other cell types, signaling is achieved by the GPI-linked GDNF family receptor α1 (GFRα1) via recruitment of transmembrane receptors: Ret (re-arranged during transformation) and/or NCAM (neural cell adhesion molecule). Here we show that GDNF enhances neuritogenesis in organotypic cultures of spiral ganglia from 5-day-old rats and mice. Addition of GFRα1-Fc increases this effect. GDNF/GFRα1-Fc stimulation activates intracellular PI3K/Akt and MEK/Erk signaling cascades as detected by Western blot analysis of cultures prepared from rats at postnatal days 5 (P5, before the onset of hearing) and 20 (P20, after the onset of hearing). Both cascades mediate GDNF stimulation of neuritogenesis, since application of the Akt inhibitor Wortmannin or the Erk inhibitor U0126 abolished GDNF/GFRα1-Fc stimulated neuritogenesis in P5 rats. Since cultures of P5 NCAM-deficient mice failed to respond by neuritogenesis to GDNF/GFRα1-Fc, we conclude that NCAM serves as a receptor for GDNF signaling responsible for neuritogenesis in early postnatal spiral ganglion.
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38
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Tian N, Leshchyns'ka I, Welch JH, Diakowski W, Yang H, Schachner M, Sytnyk V. Lipid raft-dependent endocytosis of close homolog of adhesion molecule L1 (CHL1) promotes neuritogenesis. J Biol Chem 2012; 287:44447-63. [PMID: 23144456 DOI: 10.1074/jbc.m112.394973] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
CHL1 plays a dual role by either promoting or inhibiting neuritogenesis. We report here that neuritogenesis-promoting ligand-dependent cell surface clustering of CHL1 induces palmitoylation and lipid raft-dependent endocytosis of CHL1. We identify βII spectrin as a binding partner of CHL1, and we show that partial disruption of the complex between CHL1 and βII spectrin accompanies CHL1 endocytosis. Inhibition of the association of CHL1 with lipid rafts by pharmacological disruption of lipid rafts or by mutation of cysteine 1102 within the intracellular domain of CHL1 reduces endocytosis of CHL1. Endocytosis of CHL1 is also reduced by nifedipine, an inhibitor of the L-type voltage-dependent Ca(2+) channels. CHL1-dependent neurite outgrowth is reduced by inhibitors of lipid raft assembly, inhibitors of voltage-dependent Ca(2+) channels, and overexpression of CHL1 with mutated cysteine Cys-1102. Our results suggest that ligand-induced and lipid raft-dependent regulation of CHL1 adhesion via Ca(2+)-dependent remodeling of the CHL1-βII spectrin complex and CHL1 endocytosis are required for CHL1-dependent neurite outgrowth.
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Affiliation(s)
- Nan Tian
- Zentrum für Molekulare Neurobiologie, Universitätskrankenhaus Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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39
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Thomas GM, Hayashi T, Chiu SL, Chen CM, Huganir RL. Palmitoylation by DHHC5/8 targets GRIP1 to dendritic endosomes to regulate AMPA-R trafficking. Neuron 2012; 73:482-96. [PMID: 22325201 DOI: 10.1016/j.neuron.2011.11.021] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2011] [Indexed: 11/18/2022]
Abstract
Palmitoylation, a key regulatory mechanism controlling protein targeting, is catalyzed by DHHC-family palmitoyl acyltransferases (PATs). Impaired PAT activity is linked to neurodevelopmental and neuropsychiatric disorders, suggesting critical roles for palmitoylation in neuronal function. However, few substrates for specific PATs are known, and functional consequences of palmitoylation events are frequently uncharacterized. Here, we identify the closely related PATs DHHC5 and DHHC8 as specific regulators of the PDZ domain protein GRIP1b. Binding, palmitoylation, and dendritic targeting of GRIP1b require a PDZ ligand unique to DHHC5/8. Palmitoylated GRIP1b is targeted to trafficking endosomes and may link endosomes to kinesin motors. Consistent with this trafficking role, GRIP1b's palmitoylation turnover rate approaches the highest of all reported proteins, and palmitoylation increases GRIP1b's ability to accelerate AMPA-R recycling. To our knowledge, these findings identify the first neuronal DHHC5/8 substrate, define novel mechanisms controlling palmitoylation specificity, and suggest further links between dysregulated palmitoylation and neuropathological conditions.
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Affiliation(s)
- Gareth M Thomas
- Department of Neuroscience and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Hunterian 1001, 725 N. Wolfe Street, Baltimore, MD 21205, USA
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40
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Li Y, Martin BR, Cravatt BF, Hofmann SL. DHHC5 protein palmitoylates flotillin-2 and is rapidly degraded on induction of neuronal differentiation in cultured cells. J Biol Chem 2012; 287:523-530. [PMID: 22081607 PMCID: PMC3249106 DOI: 10.1074/jbc.m111.306183] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 11/07/2011] [Indexed: 01/20/2023] Open
Abstract
Post-translational palmitoylation of intracellular proteins is mediated by protein palmitoyltransferases belonging to the DHHC family, which share a common catalytic Asp-His-His-Cys (DHHC) motif. Several members have been implicated in neuronal development, neurotransmission, and synaptic plasticity. We previously observed that mice homozygous for a hypomorphic allele of the ZDHHC5 gene are impaired in context-dependent learning and memory. To identify potentially relevant protein substrates of DHHC5, we performed a quantitative proteomic analysis of stable isotope-labeled neuronal stem cell cultures from forebrains of normal and DHHC5-GT (gene-trapped) mice using the bioorthogonal palmitate analog 17-octadecynoic acid. We identified ∼300 17-octadecynoic acid-modified and hydroxylamine-sensitive proteins, of which a subset was decreased in abundance in DHHC5-GT cells. Palmitoylation and oligomerization of one of these proteins (flotillin-2) was abolished in DHHC5-GT neuronal stem cells. In COS-1 cells, overexpression of DHHC5 markedly stimulated the palmitoylation of flotillin-2, strongly suggesting a direct enzyme-substrate relationship. Serendipitously, we found that down-regulation of DHHC5 was triggered within minutes following growth factor withdrawal from normal neural stem cells, a maneuver that is used to induce neural differentiation in culture. The effect was reversible for up to 4 h, and degradation was partially prevented by inhibitors of ubiquitin-mediated proteolysis. These findings suggest that protein palmitoylation can be regulated through changes in DHHC PAT levels in response to differentiation signals.
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Affiliation(s)
- Yi Li
- Hamon Center for Therapeutic Oncology Research and Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-8593
| | - Brent R Martin
- Skaggs Institute of Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037
| | - Benjamin F Cravatt
- Skaggs Institute of Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037
| | - Sandra L Hofmann
- Hamon Center for Therapeutic Oncology Research and Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-8593.
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41
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Korycka J, Łach A, Heger E, Bogusławska DM, Wolny M, Toporkiewicz M, Augoff K, Korzeniewski J, Sikorski AF. Human DHHC proteins: a spotlight on the hidden player of palmitoylation. Eur J Cell Biol 2011; 91:107-17. [PMID: 22178113 DOI: 10.1016/j.ejcb.2011.09.013] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 09/14/2011] [Accepted: 09/19/2011] [Indexed: 11/24/2022] Open
Abstract
Palmitoylation is one of the most common posttranslational lipid modifications of proteins and we now know quite a lot about it. However, the state of knowledge about the enzymes that catalyze this process is clearly insufficient. This review is focused on 23 human DHHC genes and their products - protein palmitoyltransferases. Here we describe mainly the structure and function of these proteins, but also, to a lesser degree, what the substrates of the enzymes are and whether they are related to various diseases. The main aim of this review was to catalogue existing information concerning the human DHHC family of genes/proteins, making them and their functions easier to understand.
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Affiliation(s)
- Justyna Korycka
- University of Wrocław, Laboratory of Cytobiochemistry, Biotechnology Faculty, Przybyszewskiego 63-77, 51-148 Wrocław, Poland
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Kudryashova IV. Structural and functional modifications of presynaptic afferents: Do they correlate with learning mechanisms? NEUROCHEM J+ 2011. [DOI: 10.1134/s181971241104009x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Janas T, Janas T. Membrane oligo- and polysialic acids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2923-32. [DOI: 10.1016/j.bbamem.2011.08.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/29/2011] [Accepted: 08/31/2011] [Indexed: 10/17/2022]
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Greaves J, Chamberlain LH. DHHC palmitoyl transferases: substrate interactions and (patho)physiology. Trends Biochem Sci 2011; 36:245-53. [DOI: 10.1016/j.tibs.2011.01.003] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/18/2011] [Accepted: 01/21/2011] [Indexed: 11/26/2022]
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Update in the methodology of the chronic stress paradigm: internal control matters. Behav Brain Funct 2011; 7:9. [PMID: 21524310 PMCID: PMC3111355 DOI: 10.1186/1744-9081-7-9] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Accepted: 04/27/2011] [Indexed: 01/21/2023] Open
Abstract
To date, the reliability of induction of a depressive-like state using chronic stress models is confronted by many methodological limitations. We believe that the modifications to the stress paradigm in mice proposed herein allow some of these limitations to be overcome. Here, we discuss a variant of the standard stress paradigm, which results in anhedonia. This anhedonic state was defined by a decrease in sucrose preference that was not exhibited by all animals. As such, we propose the use of non-anhedonic, stressed mice as an internal control in experimental mouse models of depression. The application of an internal control for the effects of stress, along with optimized behavioural testing, can enable the analysis of biological correlates of stress-induced anhedonia versus the consequences of stress alone in a chronic-stress depression model. This is illustrated, for instance, by distinct physiological and molecular profiles in anhedonic and non-anhedonic groups subjected to stress. These results argue for the use of a subgroup of individuals who are negative for the induction of a depressive phenotype during experimental paradigms of depression as an internal control, for more refined modeling of this disorder in animals.
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Levy AD, Devignot V, Fukata Y, Fukata M, Sobel A, Chauvin S. Subcellular Golgi localization of stathmin family proteins is promoted by a specific set of DHHC palmitoyl transferases. Mol Biol Cell 2011; 22:1930-42. [PMID: 21471001 PMCID: PMC3103408 DOI: 10.1091/mbc.e10-10-0824] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Palmitoylation of the neuronal microtubule regulatory stathmin phosphoproteins is crucial for their Golgi and vesicle localization and trafficking along neurites. It is promoted by a specific set of palmitoyl transferases, which suggests that palmitoylation can be viewed as a crucial regulatory process for neuronal stathmin functions. Protein palmitoylation is a reversible lipid modification that plays critical roles in protein sorting and targeting to specific cellular compartments. The neuronal microtubule-regulatory phosphoproteins of the stathmin family (SCG10/stathmin 2, SCLIP/stathmin 3, and RB3/stathmin 4) are peripheral proteins that fulfill specific and complementary roles in the formation and maturation of the nervous system. All neuronal stathmins are localized at the Golgi complex and at vesicles along axons and dendrites. Their membrane anchoring results from palmitoylation of two close cysteine residues present within their homologous N-terminal targeting domains. By preventing palmitoylation with 2-bromopalmitate or disrupting the integrity of the Golgi with brefeldin A, we were able to show that palmitoylation of stathmins 2 and 3 likely occurs at the Golgi and is crucial for their specific subcellular localization and trafficking. In addition, this membrane binding is promoted by a specific set of palmitoyl transferases that localize with stathmins 2 and 3 at the Golgi, directly interact with them, and enhance their membrane association. The subcellular membrane–associated microtubule-regulatory activity of stathmins might then be fine-tuned by extracellular stimuli controlling their reversible palmitoylation, which can be viewed as a crucial regulatory process for specific and local functions of stathmins in neurons.
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Affiliation(s)
- Aurore D Levy
- INSERM U 839, Université Pierre et Marie Curie, UMR-S839, and Institut du Fer à Moulin, F-75005, Paris, France
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Roet KCD, Bossers K, Franssen EHP, Ruitenberg MJ, Verhaagen J. A meta-analysis of microarray-based gene expression studies of olfactory bulb-derived olfactory ensheathing cells. Exp Neurol 2011; 229:10-45. [PMID: 21396936 DOI: 10.1016/j.expneurol.2011.03.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 12/28/2010] [Accepted: 03/02/2011] [Indexed: 12/23/2022]
Abstract
Genome wide transcriptional profiling and large scale proteomics have emerged as two powerful methods to dissect the molecular properties of specific neural tissues or cell types on a global scale. Several genome-wide transcriptional profiling and proteomics studies have been published on cultured olfactory ensheathing cells (OEC). In this article we present a meta-analysis of all five published and publicly available micro-array gene expression datasets of cultured early-passage-OB-OEC with other cell types (Schwann cells, late-passage-OB-OEC, mucosa-OEC, an OEC cell line, and acutely dissected OEC). The aim of this meta-analysis is to identify genes and molecular pathways that are found in multiple instead of one isolated study. 454 Genes were detected in at least three out of five microarray datasets. In this "Top-list", genes involved in the biological processes "growth of neurites", "blood vessel development", "migration of cells" and "immune response" were strongly overrepresented. By applying network analysis tools, molecular networks were constructed and Hub-genes were identified that may function as key genes in the above mentioned interrelated processes. We also identified 7 genes (ENTPD2, MATN2, CTSC, PTHLH, GLRX1, COL27A1 and ID2) with uniformly higher or lower expression in early-passage-OB-OEC in all five microarray comparisons. These genes have diverse but intriguing roles in neuroprotection, neurite extension and/or tissue repair. Our meta-analysis provides novel insights into the molecular basis of OB-OEC-mediated neural repair and can serve as a repository for investigators interested in the molecular biology of OEC. This article is part of a Special Issue entitled: Understanding olfactory ensheathing glia and their prospect for nervous system repair.
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Affiliation(s)
- Kasper C D Roet
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, Meibergdreef 47, Amsterdam, The Netherlands.
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Gibson NJ. Cell adhesion molecules in context: CAM function depends on the neighborhood. Cell Adh Migr 2011; 5:48-51. [PMID: 20948304 PMCID: PMC3038097 DOI: 10.4161/cam.5.1.13639] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 09/16/2010] [Indexed: 01/03/2023] Open
Abstract
Cell adhesion molecules (CAMs) are now known to mediate much more than adhesion between cells and between cells and the extracellular matrix. Work by many researchers has illuminated their roles in modulating activation of molecules such as receptor tyrosine kinases, with subsequent effects on cell survival, migration, and process extension. CAMs also are known to serve as substrates for proteases which can create diffusible fragments capable of signaling independently from the CAM. The diversity of interactions is further modulated by membrane rafts, which can co-localize or separate potential signaling partners to affect the likelihood of a given signaling pathway being activated. Given the ever-growing number of known CAMs and the fact that their heterophilic binding in cis or in trans can affect their interactions with other molecules, including membrane-bound receptors, one would predict a wide range of effects attributable to a particular CAM in a particular cell at a particular stage of development. The function(s) of a given CAM must therefore be considered in the context of the history of the cell expressing it and the repertoire of molecules expressed both by that cell and its neighbors.
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Affiliation(s)
- Nicholas J Gibson
- Department of Neuroscience, University of Arizona, Tucson, Arizona, USA.
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NCAM-induced neurite outgrowth depends on binding of calmodulin to NCAM and on nuclear import of NCAM and fak fragments. J Neurosci 2010; 30:10784-98. [PMID: 20702708 DOI: 10.1523/jneurosci.0297-10.2010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The neural cell adhesion molecule NCAM plays important functional roles not only during nervous system development, but also in the adult after injury and in synaptic plasticity. Homophilic binding of NCAM triggers intracellular signaling events resulting in cellular responses such as neurite outgrowth that require NCAM palmitoylation-dependent raft localization and activation of the nonreceptor tyrosine kinases fyn and fak. In this study, we show that stimulation of NCAM by a function-triggering NCAM antibody results in proteolytic processing of NCAM and fak. The C-terminal fragment of NCAM, consisting of the intracellular domain, the transmembrane domain, and a stub of the extracellular domain, and the N-terminal fragment of fak are imported into the nucleus. NCAM-stimulated fak activation, generation, and nuclear import of NCAM and fak fragments as well as neurite outgrowth are abolished by mutation of the calmodulin binding motif in the intracellular domain of NCAM that is responsible for the calcium-dependent binding of calmodulin to NCAM. This mutation interferes neither with NCAM cell surface expression, palmitoylation, and raft localization nor with fyn activation. The way by which the transmembrane NCAM fragment reaches the nucleus in a calmodulin- and calcium-dependent manner is by endocytotic transport via the endoplasmic reticulum and the cytoplasm. The generation and nuclear import of NCAM and phosphorylated fak fragments resulting from NCAM stimulation may represent a signal pathway activating cellular responses in parallel or in association with classical kinase- and phosphorylation-dependent signaling cascades.
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The transcription factor Cux1 regulates dendritic morphology of cortical pyramidal neurons. PLoS One 2010; 5:e10596. [PMID: 20485671 PMCID: PMC2868054 DOI: 10.1371/journal.pone.0010596] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2010] [Accepted: 04/18/2010] [Indexed: 01/19/2023] Open
Abstract
In the murine cerebral cortex, mammalian homologues of the Cux family transcription factors, Cux1 and Cux2, have been identified as restricted molecular markers for the upper layer (II-IV) pyramidal neurons. However, their functions in cortical development are largely unknown. Here we report that increasing the intracellular level of Cux1, but not Cux2, reduced the dendritic complexity of cultured cortical pyramidal neurons. Consistently, reducing the expression of Cux1 promoted the dendritic arborization in these pyramidal neurons. This effect required the existence of the DNA-binding domains, hence the transcriptional passive repression activity of Cux1. Analysis of downstream signals suggested that Cux1 regulates dendrite development primarily through suppressing the expression of the cyclin-dependent kinase inhibitor p27Kip1, and RhoA may mediate the regulation of dendritic complexity by Cux1 and p27. Thus, Cux1 functions as a negative regulator of dendritic complexity for cortical pyramidal neurons.
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