1
|
Bai W, Huo S, Li J, Yang Y, Zhou G, Shao J. Proteomic analysis of Biliverdin protected cerebral ischemia-reperfusion injury in rats. Sci Rep 2023; 13:20525. [PMID: 37993477 PMCID: PMC10665369 DOI: 10.1038/s41598-023-47119-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 11/09/2023] [Indexed: 11/24/2023] Open
Abstract
Biliverdin, a heme metabolite, has been previously reported to alleviate cerebral ischemic reperfusion injury (CIRI). However, the alterations of brain proteome profiles underlying this treatment remain elusive. The objective of this study is to analyze the differential protein expression profile in cerebral cortex of rats involved in anti-CIRI effects of Biliverdin, providing experimental foundation for searching specific marker proteins. Rat model of MCAO/R was established, HE staining, TTC staining, TUNEL staining, and neurological behavioral examination, corner turning test, adhesive removal test, were performed to validate the effects of Biliverdin, and the results indicated that Biliverdin plays a significant role in alleviating CIRI. Furthermore, proteomic analysis of brain tissues of rats subjected to CIRI following Biliverdin treatment was performed using an integrated TMT-based quantitative proteomic approach coupled with LC-MS/MS technology to clarify the comprehensive mechanisms of Biliverdin in CIRI. First, we conducted strict quality control data for TMT experiments. Finally, a total of 7366 proteins were identified, of which 95 proteins were differentially expressed (DEPs) between the CIRI group and the Sham group and 52 between the CIRI and BV groups. In addition, two overlapping proteins among the 147 DEPs, Atg4c and Camlg, were validated by RT-qPCR and western blotting, and their levels were consistent with the results of TMT analysis. Taken together, the current findings firstly mapped comprehensive proteomic changes after CIRI treated with Biliverdin, providing a foundation for developing potentially therapeutic targets of anti-CIRI of Biliverdin and clinically prognostic biomarkers of stroke.
Collapse
Affiliation(s)
- Wenya Bai
- Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, Yunnan, People's Republic of China
| | - Siying Huo
- Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, Yunnan, People's Republic of China
| | - Junjie Li
- Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, Yunnan, People's Republic of China
| | - Yuan Yang
- Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, Yunnan, People's Republic of China
| | - Guilin Zhou
- Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, Yunnan, People's Republic of China
| | - Jianlin Shao
- Department of Anesthesiology, The First Affiliated Hospital of Kunming Medical University, 295 Xichang Road, Kunming, 650032, Yunnan, People's Republic of China.
| |
Collapse
|
2
|
Gu XJ, Su WM, Dou M, Jiang Z, Duan QQ, Wang H, Ren YL, Cao B, Wang Y, Chen YP. Identifying novel genes for amyotrophic lateral sclerosis by integrating human brain proteomes with genome-wide association data. J Neurol 2023:10.1007/s00415-023-11757-4. [PMID: 37148340 DOI: 10.1007/s00415-023-11757-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/27/2023] [Accepted: 04/29/2023] [Indexed: 05/08/2023]
Abstract
BACKGROUND Genome-Wide Association Studies (GWAS) have identified numerous risk genes for Amyotrophic Lateral Sclerosis (ALS); however, the mechanisms by which these loci confer ALS risk are uncertain. This study aims to identify novel causal proteins in the brains of patients with ALS using an integrative analytical pipeline. METHODS Using the datasets of Protein Quantitative Trait Loci (pQTL) (NpQTL1 = 376, NpQTL2 = 152), expression QTL (eQTL) (N = 452), and the largest ALS GWAS (NALS=27,205, NControls = 110,881), we performed a systematic analytical pipeline including Proteome-Wide Association Study (PWAS), Mendelian Randomization (MR), Bayesian colocalization, and Transcriptome-Wide Association Study (TWAS) to identify novel causal proteins for ALS in the brain. RESULTS Using PWAS, we found that the altered protein abundance of 12 genes in the brain was associated with ALS. Three genes (SCFD1, SARM1 and CAMLG) were identified as lead causal genes for ALS with solid evidence (False discovery rate < 0.05, in MR analysis; PPH4 > 80% for Bayesian colocalization). Specifically, an increased abundance of SCFD1 and CAMLG led to an increased risk of ALS, whereas a higher abundance of SARM1 led to a decreased risk of developing ALS. TWAS showed that SCFD1 and CAMLG were related to ALS at the transcriptional level. CONCLUSIONS SCFD1, CAMLG, and SARM1 exhibited robust associations and causality with ALS. The study findings provide novel clues for identifying potential therapeutic targets in ALS. Further studies are required to explore the mechanisms underlying the identified genes.
Collapse
Affiliation(s)
- Xiao-Jing Gu
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Wei-Ming Su
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Institute of Brain Science and Brain-Inspired Technology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Centre for Rare Diseases, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Meng Dou
- Chengdu Institute of Computer Application, Chinese Academy of Sciences, Chengdu, 610041, Sichuan, China
| | - Zheng Jiang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Institute of Brain Science and Brain-Inspired Technology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Centre for Rare Diseases, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Qing-Qing Duan
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Institute of Brain Science and Brain-Inspired Technology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Centre for Rare Diseases, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Han Wang
- Department of Pathophysiology, West China College of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yan-Ling Ren
- Department of Pathophysiology, West China College of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Bei Cao
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Institute of Brain Science and Brain-Inspired Technology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Centre for Rare Diseases, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yi Wang
- Department of Pathophysiology, West China College of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yong-Ping Chen
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
- Institute of Brain Science and Brain-Inspired Technology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
- Centre for Rare Diseases, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
| |
Collapse
|
3
|
Khayenko V, Maric HM. Targeting GABA AR-Associated Proteins: New Modulators, Labels and Concepts. Front Mol Neurosci 2019; 12:162. [PMID: 31293385 PMCID: PMC6606717 DOI: 10.3389/fnmol.2019.00162] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/12/2019] [Indexed: 12/21/2022] Open
Abstract
γ-aminobutyric acid type A receptors (GABAARs) are the major mediators of synaptic inhibition in the brain. Aberrant GABAAR activity or regulation is observed in various neurodevelopmental disorders, neurodegenerative diseases and mental illnesses, including epilepsy, Alzheimer’s and schizophrenia. Benzodiazepines, anesthetics and other pharmaceutics targeting these receptors find broad clinical use, but their inherent lack of receptor subtype specificity causes unavoidable side effects, raising a need for new or adjuvant medications. In this review article, we introduce a new strategy to modulate GABAeric signaling: targeting the intracellular protein interactors of GABAARs. Of special interest are scaffolding, anchoring and supporting proteins that display high GABAAR subtype specificity. Recent efforts to target gephyrin, the major intracellular integrator of GABAergic signaling, confirm that GABAAR-associated proteins can be successfully targeted through diverse molecules, including recombinant proteins, intrabodies, peptide-based probes and small molecules. Small-molecule artemisinins and peptides derived from endogenous interactors, that specifically target the universal receptor binding site of gephyrin, acutely affect synaptic GABAAR numbers and clustering, modifying neuronal transmission. Interference with GABAAR trafficking provides another way to modulate inhibitory signaling. Peptides blocking the binding site of GABAAR to AP2 increase the surface concentration of GABAAR clusters and enhance GABAergic signaling. Engineering of gephyrin binding peptides delivered superior means to interrogate neuronal structure and function. Fluorescent peptides, designed from gephyrin binders, enable live neuronal staining and visualization of gephyrin in the post synaptic sites with submicron resolution. We anticipate that in the future, novel fluorescent probes, with improved size and binding efficiency, may find wide application in super resolution microscopy studies, enlightening the nanoscale architecture of the inhibitory synapse. Broader studies on GABAAR accessory proteins and the identification of the exact molecular binding interfaces and affinities will advance the development of novel GABAAR modulators and following in vivo studies will reveal their clinical potential as adjuvant or stand-alone drugs.
Collapse
Affiliation(s)
- Vladimir Khayenko
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany.,Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Hans Michael Maric
- Institute of Structural Biology, Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany.,Department of Biotechnology and Biophysics, Biocenter, University of Würzburg, Würzburg, Germany
| |
Collapse
|
4
|
Classical Swine Fever Virus p7 Protein Interacts with Host Protein CAMLG and Regulates Calcium Permeability at the Endoplasmic Reticulum. Viruses 2018; 10:v10090460. [PMID: 30154321 PMCID: PMC6165257 DOI: 10.3390/v10090460] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/14/2022] Open
Abstract
We have previously shown that Classical Swine Fever Virus (CSFV) p7 is an essential nonstructural protein with a viroporin activity, a critical function in the progression of virus infection. We also identified p7 domains and amino acid residues critical for pore formation. Here, we describe how p7 specifically interacts with host protein CAMLG, an integral ER transmembrane protein involved in intracellular calcium release regulation and signal response generation. Detection of interaction as well as the identification of p7 areas mediating interaction with CAMLG was performed by yeast two-hybrid. p7-CAMLG interaction was further confirmed by confocal microscopy in eukaryotic cells, co-expressing both proteins. Mutant forms of p7 having substituted native residues identified as mediating interaction with CAMLG showed a decreased co-localization compared with the native forms of p7. Furthermore, it is shown that native p7, but not the mutated forms of p7 that fail to interact with CAMLG, efficiently mediates calcium permeability in the ER. Interestingly, viruses harboring some of those mutated forms of p7 have been previously shown to have a significantly decreased virulence in swine.
Collapse
|
5
|
Lorenz-Guertin JM, Bambino MJ, Jacob TC. γ2 GABA AR Trafficking and the Consequences of Human Genetic Variation. Front Cell Neurosci 2018; 12:265. [PMID: 30190672 PMCID: PMC6116786 DOI: 10.3389/fncel.2018.00265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/02/2018] [Indexed: 11/13/2022] Open
Abstract
GABA type A receptors (GABAARs) mediate the majority of fast inhibitory neurotransmission in the central nervous system (CNS). Most prevalent as heteropentamers composed of two α, two β, and a γ2 subunit, these ligand-gated ionotropic chloride channels are capable of extensive genetic diversity (α1-6, β1-3, γ1-3, δ, 𝜀, 𝜃, π, ρ1-3). Part of this selective GABAAR assembly arises from the critical role for γ2 in maintaining synaptic receptor localization and function. Accordingly, mutations in this subunit account for over half of the known epilepsy-associated genetic anomalies identified in GABAARs. Fundamental structure-function studies and cellular pathology investigations have revealed dynamic GABAAR trafficking and synaptic scaffolding as critical regulators of GABAergic inhibition. Here, we introduce in vitro and in vivo findings regarding the specific role of the γ2 subunit in receptor trafficking. We then examine γ2 subunit human genetic variation and assess disease related phenotypes and the potential role of altered GABAAR trafficking. Finally, we discuss new-age imaging techniques and their potential to provide novel insight into critical regulatory mechanisms of GABAAR function.
Collapse
Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew J Bambino
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| |
Collapse
|
6
|
Lan X, Fu H, Li G, Zeng W, Lin X, Zhu Y, Liu M, Chen P. TMUB1 Inhibits BRL-3A Hepatocyte Proliferation by Interfering with the Binding of CAML to Cyclophilin B through its TM1 Hydrophobic Domain. Sci Rep 2018; 8:9917. [PMID: 29967478 PMCID: PMC6028644 DOI: 10.1038/s41598-018-28339-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 06/15/2018] [Indexed: 02/06/2023] Open
Abstract
Transmembrane and ubiquitin-like domain-containing 1 (Tmub1) encodes a protein (TMUB1) containing an ubiquitin-like domain and plays a negative regulatory role during hepatocyte proliferation, but its mechanism in this process is still unknown. Here, TMUB1 interfered with the binding of calcium-modulating cyclophilin ligand (CAML) to cyclophilin B, which may represent a key role in the negative regulatory process of TMUB1 in hepatocyte proliferation. Co-immunoprecipitation assays in rat BRL-3A cells confirmed the interaction between TMUB1 and CAML; significant regulation of the influx of Ca2+ ([Ca2+]i) and hepatocyte proliferation occurred following TMUB1 overexpression or knockout. Deletion of the TM1 hydrophobic domain of TMUB1 completely abolished this interaction and led to loss of TMUB1's regulatory effects on cytological behavior. Furthermore, overexpression of TMUB1 completely abolished the interaction between CAML and its downstream protein cyclophilin B, which can act upstream of calcineurin by increasing [Ca2+]i during cell proliferation. Taken together, our results indicate that TMUB1 regulates BRL-3A hepatocyte proliferation by interacting with CAML and further interferes with the binding of CAML to cyclophilin B to decrease cellular [Ca2+]i.
Collapse
Affiliation(s)
- Xiang Lan
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China
| | - Hangwei Fu
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China
| | - Guangyao Li
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China
| | - Wei Zeng
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China
| | - Xia Lin
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China
| | - Yuanxin Zhu
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China
| | - Menggang Liu
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China.
| | - Ping Chen
- Department of Hepatobiliary Surgery, The Third Affiliated Hospital, The Third Military Medical University (Army medical university), Chongqing, China.
| |
Collapse
|
7
|
Lorenz-Guertin JM, Jacob TC. GABA type a receptor trafficking and the architecture of synaptic inhibition. Dev Neurobiol 2018; 78:238-270. [PMID: 28901728 PMCID: PMC6589839 DOI: 10.1002/dneu.22536] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/08/2017] [Accepted: 09/08/2017] [Indexed: 12/21/2022]
Abstract
Ubiquitous expression of GABA type A receptors (GABAA R) in the central nervous system establishes their central role in coordinating most aspects of neural function and development. Dysregulation of GABAergic neurotransmission manifests in a number of human health disorders and conditions that in certain cases can be alleviated by drugs targeting these receptors. Precise changes in the quantity or activity of GABAA Rs localized at the cell surface and at GABAergic postsynaptic sites directly impact the strength of inhibition. The molecular mechanisms constituting receptor trafficking to and from these compartments therefore dictate the efficacy of GABAA R function. Here we review the current understanding of how GABAA Rs traffic through biogenesis, plasma membrane transport, and degradation. Emphasis is placed on discussing novel GABAergic synaptic proteins, receptor and scaffolding post-translational modifications, activity-dependent changes in GABAA R confinement, and neuropeptide and neurosteroid mediated changes. We further highlight modern techniques currently advancing the knowledge of GABAA R trafficking and clinically relevant neurodevelopmental diseases connected to GABAergic dysfunction. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 238-270, 2018.
Collapse
Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, 15261
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, 15261
| |
Collapse
|
8
|
Shing JC, Lindquist LD, Borgese N, Bram RJ. CAML mediates survival of Myc-induced lymphoma cells independent of tail-anchored protein insertion. Cell Death Discov 2017; 3:16098. [PMID: 28580168 PMCID: PMC5447128 DOI: 10.1038/cddiscovery.2016.98] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/06/2016] [Accepted: 11/23/2016] [Indexed: 12/17/2022] Open
Abstract
Calcium-modulating cyclophilin ligand (CAML) is an endoplasmic reticulum (ER) protein that functions, along with WRB and TRC40, to mediate tail-anchored (TA) protein insertion into the ER membrane. Physiologic roles for CAML include endocytic trafficking, intracellular calcium signaling, and the survival and proliferation of specialized immune cells, recently attributed to its requirement for TA protein insertion. To identify a possible role for CAML in cancer cells, we generated Eμ-Myc transgenic mice that carry a tamoxifen-inducible deletion allele of Caml. In multiple B-cell lymphoma cell lines derived from these mice, homozygous loss of Caml activated apoptosis. Cell death was blocked by Bcl-2/Bcl-xL overexpression; however, rescue from apoptosis was insufficient to restore proliferation. Tumors established from an Eμ-Myc lymphoma cell line completely regressed after tamoxifen administration, suggesting that CAML is also required for these cancer cells to survive and grow in vivo. Cell cycle analyses of Caml-deleted lymphoma cells revealed an arrest in G2/M, accompanied by low expression of the mitotic marker, phospho-histone H3 (Ser10). Surprisingly, lymphoma cell viability did not depend on the domain of CAML required for its interaction with TRC40. Furthermore, a small protein fragment consisting of the C-terminal 111 amino acid residues of CAML, encompassing the WRB-binding domain, was sufficient to rescue growth and survival of Caml-deleted lymphoma cells. Critically, this minimal region of CAML did not restore TA protein insertion in knockout cells. Taken together, these data reveal an essential role for CAML in supporting survival and mitotic progression in Myc-driven lymphomas that is independent of its TA protein insertion function.
Collapse
Affiliation(s)
- Jennifer C Shing
- Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Lonn D Lindquist
- Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Nica Borgese
- Consiglio Nazionale delle Ricerche Institute of Neuroscience, Milan, Italy
| | - Richard J Bram
- Department of Pediatric and Adolescent Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA.,Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| |
Collapse
|
9
|
Kilpatrick CL, Murakami S, Feng M, Wu X, Lal R, Chen G, Du K, Luscher B. Dissociation of Golgi-associated DHHC-type Zinc Finger Protein (GODZ)- and Sertoli Cell Gene with a Zinc Finger Domain-β (SERZ-β)-mediated Palmitoylation by Loss of Function Analyses in Knock-out Mice. J Biol Chem 2016; 291:27371-27386. [PMID: 27875292 DOI: 10.1074/jbc.m116.732768] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 09/28/2016] [Indexed: 11/06/2022] Open
Abstract
The γ2 subunit of GABA type A receptors (GABAARs) is thought to be subject to palmitoylation by both Golgi-associated DHHC-type zinc finger protein (GODZ; also known as DHHC3) and its paralog Sertoli cell gene with a zinc finger domain-β (SERZ-β; DHHC7) based on overexpression of enzymes and substrates in heterologous cells. Here we have further investigated the substrate specificity of these enzymes by characterization of GODZ and SERZ-β knock-out (KO) mice as well as double KO (DKO) neurons. Palmitoylation of γ2 and a second substrate, growth-associated protein of 43 kDa, that is independently implicated in trafficking of GABAARs was significantly reduced in brain of GODZ KO versus wild-type (WT) mice but unaltered in SERZ-β KO mice. Accumulation of GABAARs at synapses, GABAergic innervation, and synaptic function were reduced in GODZ KO and DKO neurons to a similar extent, indicating that SERZ-β does not contribute to palmitoylation or trafficking of GABAARs even in the absence of GODZ. Notably, these effects were seen only when mutant neurons were grown in competition with WT neurons, thereby mimicking conditions of shRNA-transfected neurons previously used to characterize GODZ. However, GABA-evoked whole-cell currents of DKO neurons and the GABAAR cell surface expression in DKO neurons and GODZ or SERZ-β KO brain slices were unaltered, indicating that GODZ-mediated palmitoylation selectively controls the pool of receptors at synapses. The different substrate specificities of GODZ and SERZ-β in vivo were correlated with their differential localization to cis- versus trans-Golgi compartment, a mechanism that was compromised by overexpression of GODZ.
Collapse
Affiliation(s)
| | | | | | | | | | - Gong Chen
- Biology and.,the Center for Molecular Investigation of Neurological Disorders (CMIND), Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Keyong Du
- Molecular Oncology Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - Bernhard Luscher
- From the Departments of Biochemistry and Molecular Biology and .,Biology and.,the Center for Molecular Investigation of Neurological Disorders (CMIND), Pennsylvania State University, University Park, Pennsylvania 16802 and
| |
Collapse
|
10
|
Ren Z, Pribiag H, Jefferson SJ, Shorey M, Fuchs T, Stellwagen D, Luscher B. Bidirectional Homeostatic Regulation of a Depression-Related Brain State by Gamma-Aminobutyric Acidergic Deficits and Ketamine Treatment. Biol Psychiatry 2016; 80:457-468. [PMID: 27062563 PMCID: PMC4983262 DOI: 10.1016/j.biopsych.2016.02.009] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/06/2016] [Accepted: 02/08/2016] [Indexed: 12/30/2022]
Abstract
BACKGROUND Major depressive disorder is increasingly recognized to involve functional deficits in both gamma-aminobutyric acid (GABA)ergic and glutamatergic synaptic transmission. To elucidate the relationship between these phenotypes, we used GABAA receptor γ2 subunit heterozygous (γ2(+/-)) mice, which we previously characterized as a model animal with construct, face, and predictive validity for major depressive disorder. METHODS To assess possible consequences of GABAergic deficits on glutamatergic transmission, we quantitated the cell surface expression of N-methyl-D-aspartate (NMDA)-type and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors and the function of synapses in the hippocampus and medial prefrontal cortex of γ2(+/-) mice. We also analyzed the effects of an acute dose of the experimental antidepressant ketamine on all these parameters in γ2(+/-) versus wild-type mice. RESULTS Modest defects in GABAergic synaptic transmission of γ2(+/-) mice resulted in a strikingly prominent homeostatic-like reduction in the cell surface expression of NMDA-type and AMPA-type glutamate receptors, along with prominent functional impairment of glutamatergic synapses in the hippocampus and medial prefrontal cortex. A single subanesthetic dose of ketamine normalized glutamate receptor expression and synaptic function of γ2(+/-) mice to wild-type levels for a prolonged period, along with antidepressant-like behavioral consequences selectively in γ2(+/-) mice. The GABAergic synapses of γ2(+/-) mice were potentiated by ketamine in parallel but only in the medial prefrontal cortex. CONCLUSIONS Depressive-like brain states that are caused by GABAergic deficits involve a homeostatic-like reduction of glutamatergic transmission that is reversible by an acute, subanesthetic dose of ketamine, along with regionally selective potentiation of GABAergic synapses. The data merge the GABAergic and glutamatergic deficit hypotheses of major depressive disorder.
Collapse
Affiliation(s)
- Zhen Ren
- Department of Biology, Pennsylvania State University, University Park, PA 16802
| | - Horia Pribiag
- Center for Research in Neuroscience, McGill University, Montreal General Hospital, L7-132, 1650 Cedar Av, Montreal, QC H3G 1A4, Canada
| | - Sarah J. Jefferson
- Department of Biology, Pennsylvania State University, University Park, PA 16802
| | - Matthew Shorey
- Department of Biology, Pennsylvania State University, University Park, PA 16802
| | - Thomas Fuchs
- Department of Biology, Pennsylvania State University, University Park, PA 16802
| | - David Stellwagen
- Center for Research in Neuroscience, McGill University, Montreal General Hospital, L7-132, 1650 Cedar Av, Montreal, QC H3G 1A4, Canada
| | - Bernhard Luscher
- Departments of Biology, Pennsylvania State University, University Park, Pennsylvania; Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania; Center for Molecular Investigation of Neurological Disorders, Pennsylvania State University, University Park, Pennsylvania.
| |
Collapse
|
11
|
Colombo SF, Cardani S, Maroli A, Vitiello A, Soffientini P, Crespi A, Bram RF, Benfante R, Borgese N. Tail-anchored Protein Insertion in Mammals: FUNCTION AND RECIPROCAL INTERACTIONS OF THE TWO SUBUNITS OF THE TRC40 RECEPTOR. J Biol Chem 2016; 291:15292-306. [PMID: 27226539 DOI: 10.1074/jbc.m115.707752] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Indexed: 11/06/2022] Open
Abstract
The GET (guided entry of tail-anchored proteins)/TRC (transmembrane recognition complex) pathway for tail-anchored protein targeting to the endoplasmic reticulum (ER) has been characterized in detail in yeast and is thought to function similarly in mammals, where the orthologue of the central ATPase, Get3, is known as TRC40 or Asna1. Get3/TRC40 function requires an ER receptor, which in yeast consists of the Get1/Get2 heterotetramer and in mammals of the WRB protein (tryptophan-rich basic protein), homologous to yeast Get1, in combination with CAML (calcium-modulating cyclophilin ligand), which is not homologous to Get2. To better characterize the mammalian receptor, we investigated the role of endogenous WRB and CAML in tail-anchored protein insertion as well as their association, concentration, and stoichiometry in rat liver microsomes and cultured cells. Functional proteoliposomes, reconstituted from a microsomal detergent extract, lost their activity when made with an extract depleted of TRC40-associated proteins or of CAML itself, whereas in vitro synthesized CAML and WRB together were sufficient to confer insertion competence to liposomes. CAML was found to be in ∼5-fold excess over WRB, and alteration of this ratio did not inhibit insertion. Depletion of each subunit affected the levels of the other one; in the case of CAML silencing, this effect was attributable to destabilization of the WRB transcript and not of WRB protein itself. These results reveal unanticipated complexity in the mutual regulation of the TRC40 receptor subunits and raise the question as to the role of the excess CAML in the mammalian ER.
Collapse
Affiliation(s)
- Sara Francesca Colombo
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| | - Silvia Cardani
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| | - Annalisa Maroli
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| | - Adriana Vitiello
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| | - Paolo Soffientini
- IFOM, the FIRC Institute for Molecular Oncology Foundation, Milan, Italy 20100 and
| | - Arianna Crespi
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| | | | - Roberta Benfante
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| | - Nica Borgese
- From the CNR Institute of Neuroscience and BIOMETRA Department, Università degli Studi di Milano and
| |
Collapse
|
12
|
Kneussel M, Hausrat TJ. Postsynaptic Neurotransmitter Receptor Reserve Pools for Synaptic Potentiation. Trends Neurosci 2016; 39:170-182. [PMID: 26833258 DOI: 10.1016/j.tins.2016.01.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/06/2016] [Accepted: 01/07/2016] [Indexed: 11/18/2022]
Abstract
At excitatory and inhibitory synapses, an immediate transfer of additional neurotransmitter receptors from non-synaptic positions to the synapse mediates synaptic long-term potentiation (LTP). Different types of non-synaptic reserve pools permit the rapid supply of transmembrane neurotransmitter receptors. Recycling endosomes (REs) serve as an intracellular reservoir of receptors that is delivered to the plasma membrane on LTP induction. Furthermore, AMPA receptors at the non-synaptic plasma membrane provide an extrasynaptic reserve pool that is also important to potentiate synapse function. Finally, bidirectional synaptic versus extrasynaptic trapping of freely diffusing plasma membrane GABAA receptors (GABAARs) by scaffolding proteins modulates synaptic transmission. Here we discuss novel findings regarding neurotransmitter receptor reservoirs and potential reserve pool mechanisms for synaptic potentiation.
Collapse
Affiliation(s)
- Matthias Kneussel
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany.
| | - Torben Johann Hausrat
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| |
Collapse
|
13
|
Chen W, Sheng J, Guo J, Gao F, Zhao X, Dai J, Wang G, Li K. Tumor necrosis factor-α enhances voltage-gated Na⁺ currents in primary culture of mouse cortical neurons. J Neuroinflammation 2015; 12:126. [PMID: 26112872 PMCID: PMC4510892 DOI: 10.1186/s12974-015-0349-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 06/18/2015] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Previous studies showed that TNF-α could activate voltage-gated Na(+) channels (VGSCs) in the peripheral nervous system (PNS). Since TNF-α is implicated in many central nervous system (CNS) diseases, we examined potential effects of TNF-α on VGSCs in the CNS. METHODS Effects of TNF-α (1-1000 pg/mL, for 4-48 h) on VGSC currents were examined using whole-cell voltage clamp and current clamp techniques in primary culture of mouse cortical neurons. Expression of Nav1.1, Nav1.2, Nav1.3, and Nav1.6 were examined at both the mRNA and protein levels, prior to and after TNF-α exposure. RESULTS TNF-α increased Na(+) currents by accelerating the activation of VGSCs. The threshold for action potential (AP) was decreased and firing rate were increased. VGSCs were up-regulated at both the mRNA and protein levels. The observed effects of TNF-α on Na(+) currents were inhibited by pre-incubation with the NF-κB inhibitor BAY 11-7082 (1 μM) or the p38 mitogen-activated protein kinases (MAPK) inhibitor SB203580 (1 μM). CONCLUSIONS TNF-α increases Na(+) currents by accelerating the channel activation as well as increasing the expression of VGSCs in a mechanism dependent upon NF-κB and p38 MAPK signal pathways in CNS neurons.
Collapse
Affiliation(s)
- Weiqiang Chen
- Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
- Department of Neurosurgery, First Affiliated Hospital, Shantou University Medical College, 57 Changping Road, Shantou, 515041, , Guangdong, China.
| | - Jiangtao Sheng
- Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
| | - Jingfang Guo
- Department of Neurosurgery, First Affiliated Hospital, Shantou University Medical College, 57 Changping Road, Shantou, 515041, , Guangdong, China.
| | - Fenfei Gao
- Department of Pharmacology, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
| | - Xiangfeng Zhao
- Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
| | - Jianping Dai
- Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
| | - Gefei Wang
- Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
| | - Kangsheng Li
- Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, 22 Xinling Road, Shantou, 515041, , Guangdong, China.
| |
Collapse
|
14
|
Yamamoto Y, Sakisaka T. The emerging role of calcium-modulating cyclophilin ligand in posttranslational insertion of tail-anchored proteins into the endoplasmic reticulum membrane. J Biochem 2015; 157:419-29. [PMID: 25869254 DOI: 10.1093/jb/mvv035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 02/18/2015] [Indexed: 01/08/2023] Open
Abstract
Tail-anchored (TA) proteins, a class of membrane proteins having an N-terminal cytoplasmic region anchored to the membrane by a single C-terminal transmembrane domain, are posttranslationally inserted into the endoplasmic reticulum (ER) membrane. In yeasts, the posttranslational membrane insertion is mediated by the Guided Entry of TA Proteins (GET) complex. Get3, a cytosolic ATPase, targets newly synthesized TA proteins to the ER membrane, where Get2 and Get3 constitute the Get3 receptor driving the membrane insertion. While mammalian cells employ TRC40 and WRB, mammalian homologs of Get3 and Get1, respectively, they lack the gene homologous to Get2. We recently identified calcium-modulating cyclophilin ligand (CAML) as a TRC40 receptor, indicating that CAML was equivalent to Get2 in the context of the membrane insertion. On the other hand, CAML has been well characterized as a signaling molecule that regulates various biological processes, raising the question of how the two distinct actions of CAML, the membrane insertion and the signal transduction, are assembled. In this review, we summarize recent progress of the molecular mechanism of the membrane insertion of TA proteins and discuss the possibility that CAML could sense the various signals at the ER membrane, thereby controlling TA protein biogenesis.
Collapse
Affiliation(s)
- Yasunori Yamamoto
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Toshiaki Sakisaka
- Division of Membrane Dynamics, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| |
Collapse
|
15
|
Comenencia-Ortiz E, Moss SJ, Davies PA. Phosphorylation of GABAA receptors influences receptor trafficking and neurosteroid actions. Psychopharmacology (Berl) 2014; 231:3453-65. [PMID: 24847959 PMCID: PMC4135009 DOI: 10.1007/s00213-014-3617-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 05/02/2014] [Indexed: 01/06/2023]
Abstract
RATIONALE Gamma-aminobutyric acid type A receptors (GABAARs) are the principal mediators of inhibitory transmission in the mammalian central nervous system. GABAARs can be localized at post-synaptic inhibitory specializations or at extrasynaptic sites. While synaptic GABAARs are activated transiently following the release of GABA from presynaptic vesicles, extrasynaptic GABAARs are typically activated continuously by ambient GABA concentrations and thus mediate tonic inhibition. The tonic inhibitory currents mediated by extrasynaptic GABAARs control neuronal excitability and the strength of synaptic transmission. However, the mechanisms by which neurons control the functional properties of extrasynaptic GABAARs had not yet been explored. OBJECTIVES We review GABAARs, how they are assembled and trafficked, and the role phosphorylation has on receptor insertion and membrane stabilization. Finally, we review the modulation of GABAARs by neurosteroids and how GABAAR phosphorylation can influence the actions of neurosteroids. CONCLUSIONS Trafficking and stability of functional channels to the membrane surface are critical for inhibitory efficacy. Phosphorylation of residues within GABAAR subunits plays an essential role in the assembly, trafficking, and cell surface stability of GABAARs. Neurosteroids are produced in the brain and are highly efficacious allosteric modulators of GABAAR-mediated current. This allosteric modulation by neurosteroids is influenced by the phosphorylated state of the GABAAR which is subunit dependent, adding temporal and regional variability to the neurosteroid response. Possible links between neurosteroid actions, phosphorylation, and GABAAR trafficking remain to be explored, but potential novel therapeutic targets may exist for numerous neurological and psychological disorders which are linked to fluctuations in neurosteroid levels and GABAA subunit expression.
Collapse
|
16
|
Ren Z, Sahir N, Murakami S, Luellen BA, Earnheart JC, Lal R, Kim JY, Song H, Luscher B. Defects in dendrite and spine maturation and synaptogenesis associated with an anxious-depressive-like phenotype of GABAA receptor-deficient mice. Neuropharmacology 2014; 88:171-9. [PMID: 25107590 DOI: 10.1016/j.neuropharm.2014.07.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/08/2014] [Accepted: 07/21/2014] [Indexed: 11/27/2022]
Abstract
Mice that were rendered heterozygous for the γ2 subunit of GABAA receptors (γ2(+/-) mice) have been characterized extensively as a model for major depressive disorder. The phenotype of these mice includes behavior indicative of heightened anxiety, despair, and anhedonia, as well as defects in hippocampus-dependent pattern separation, HPA axis hyperactivity and increased responsiveness to antidepressant drugs. The γ2(+/-) model thereby provides strong support for the GABAergic deficit hypothesis of major depressive disorder. Here we show that γ2(+/-) mice additionally exhibit specific defects in late stage survival of adult-born hippocampal granule cells, including reduced complexity of dendritic arbors and impaired maturation of synaptic spines. Moreover, cortical γ2(+/-) neurons cultured in vitro show marked deficits in GABAergic innervation selectively when grown under competitive conditions that may mimic the environment of adult-born hippocampal granule cells. Finally, brain extracts of γ2(+/-) mice show a numerical but insignificant trend (p = 0.06) for transiently reduced expression of brain derived neurotrophic factor (BDNF) at three weeks of age, which might contribute to the previously reported developmental origin of the behavioral phenotype of γ2(+/-) mice. The data indicate increasing congruence of the GABAergic, glutamatergic, stress-based and neurotrophic deficit hypotheses of major depressive disorder.
Collapse
Affiliation(s)
- Zhen Ren
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Molecular Investigation of Neurological Disorders, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Nadia Sahir
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shoko Murakami
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Beth A Luellen
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - John C Earnheart
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Rachnanjali Lal
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Ju Young Kim
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hongjun Song
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Bernhard Luscher
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; Center for Molecular Investigation of Neurological Disorders, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
| |
Collapse
|
17
|
Vilardi F, Stephan M, Clancy A, Janshoff A, Schwappach B. WRB and CAML are necessary and sufficient to mediate tail-anchored protein targeting to the ER membrane. PLoS One 2014; 9:e85033. [PMID: 24392163 PMCID: PMC3879356 DOI: 10.1371/journal.pone.0085033] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/21/2013] [Indexed: 02/01/2023] Open
Abstract
Tail-Anchored (TA) proteins are inserted into the endoplasmic reticulum (ER) membrane of yeast cells via the posttranslational Guided Entry of Tail-Anchored protein (GET) pathway. The key component of this targeting machinery is the ATPase Get3 that docks to the ER membrane by interacting with a receptor complex formed by the proteins Get1 and Get2. A conserved pathway is present in higher eukaryotes and is mediated by TRC40, homolog of Get3, and the recently identified membrane receptors WRB and CAML. Here, we used yeast lacking the GET1 and GET2 genes and substituted them with WRB and CAML. This rescued the growth phenotypes of the GET receptor mutant. We demonstrate that WRB and CAML efficiently recruit Get3 to the ER membrane and promote the targeting of the TA proteins in vivo. Our results show that the membrane spanning segments of CAML are essential to create a functional receptor with WRB and to ensure TA protein membrane insertion. Finally, we determined the binding parameters of TRC40 to the WRB/CAML receptor. We conclude that together, WRB and CAML are not only necessary but also sufficient to create a functional membrane receptor complex for TRC40. The yeast complementation assay can be used to further dissect the structure-function relationship of the WRB/CAML heteromultimer in the absence of endogenous receptor proteins.
Collapse
Affiliation(s)
- Fabio Vilardi
- Institute of Molecular Biology, University of Göttingen, Göttingen, Germany
| | - Milena Stephan
- Institute of Physical Chemistry, University of Göttingen, Göttingen, Germany
| | - Anne Clancy
- Institute of Molecular Biology, University of Göttingen, Göttingen, Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, University of Göttingen, Göttingen, Germany
| | - Blanche Schwappach
- Institute of Molecular Biology, University of Göttingen, Göttingen, Germany
- * E-mail:
| |
Collapse
|
18
|
Long T, Su J, Tang W, Luo Z, Liu S, Liu Z, Zhou H, Qi M, Zeng W, Zhang J, Chen X. A novel interaction between calcium-modulating cyclophilin ligand and Basigin regulates calcium signaling and matrix metalloproteinase activities in human melanoma cells. Cancer Lett 2013; 339:93-101. [PMID: 23879967 DOI: 10.1016/j.canlet.2013.07.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/11/2013] [Accepted: 07/15/2013] [Indexed: 12/30/2022]
Abstract
Intracellular free calcium is a ubiquitous second messenger regulating a multitude of normal and pathogenic cellular responses, including the development of melanoma. Upstream signaling pathways regulating the intracellular free calcium concentration ([Ca2+]i) may therefore have a significant impact on melanoma growth and metastasis. In this study, we demonstrate that the endoplasmic reticulum (ER)-associated protein calcium-modulating cyclophilin ligand (CAML) is bound to Basigin, a widely expressed integral plasma membrane glycoprotein and extracellular matrix metalloproteinase inducer (EMMPRIN, or CD147) implicated in melanoma proliferation, invasiveness, and metastasis. This interaction between CAML and Basigin was first identified using yeast two-hybrid screening and further confirmed by co-immunoprecipitation. In human A375 melanoma cells, CAML and Basigin were co-localized to the ER. Knockdown of Basigin in melanoma cells by siRNA significantly decreased resting [Ca2+]i and the [Ca2+]i increase induced by the sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibitor thapsigargin (TG), indicating that the interaction between CAML and Basigin regulates ER-dependent [Ca2+]i signaling. Meanwhile upregulating the [Ca2+]i either by TG or phorbol myristate acetate (PMA) could stimulate the production of MMP-9 in A375 cells with the expression of Basigin. Our study has revealed a previously uncharacterized [Ca2+]i signaling pathway that may control melanoma invasion, and metastasis. Disruption of this pathway may be a novel therapeutic strategy for melanoma treatment.
Collapse
Affiliation(s)
- Tingting Long
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, Hunan, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Kong Q, Mills JL, Kundu B, Li X, Qing L, Surewicz K, Cali I, Huang S, Zheng M, Swietnicki W, Sönnichsen FD, Gambetti P, Surewicz WK. Thermodynamic stabilization of the folded domain of prion protein inhibits prion infection in vivo. Cell Rep 2013; 4:248-54. [PMID: 23871665 DOI: 10.1016/j.celrep.2013.06.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 05/29/2013] [Accepted: 06/21/2013] [Indexed: 10/26/2022] Open
Abstract
Prion diseases, or transmissible spongiform encephalopathies (TSEs), are associated with the conformational conversion of the cellular prion protein, PrP(C), into a protease-resistant form, PrP(Sc). Here, we show that mutation-induced thermodynamic stabilization of the folded, α-helical domain of PrP(C) has a dramatic inhibitory effect on the conformational conversion of prion protein in vitro, as well as on the propagation of TSE disease in vivo. Transgenic mice expressing a human prion protein variant with increased thermodynamic stability were found to be much more resistant to infection with the TSE agent than those expressing wild-type human prion protein, in both the primary passage and three subsequent subpassages. These findings not only provide a line of evidence in support of the protein-only model of TSEs but also yield insight into the molecular nature of the PrP(C)→PrP(Sc) conformational transition, and they suggest an approach to the treatment of prion diseases.
Collapse
Affiliation(s)
- Qingzhong Kong
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Wu X, Huang L, Wu Z, Zhang C, Jiang D, Bai Y, Wang Y, Chen G. Homeostatic competition between phasic and tonic inhibition. J Biol Chem 2013; 288:25053-25065. [PMID: 23839941 DOI: 10.1074/jbc.m113.491464] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The GABAA receptors are the major inhibitory receptors in the brain and are localized at both synaptic and extrasynaptic membranes. Synaptic GABAA receptors mediate phasic inhibition, whereas extrasynaptic GABAA receptors mediate tonic inhibition. Both phasic and tonic inhibitions regulate neuronal activity, but whether they regulate each other is not very clear. Here, we investigated the functional interaction between synaptic and extrasynaptic GABAA receptors through various molecular manipulations. Overexpression of extrasynaptic α6β3δ-GABAA receptors in mouse hippocampal pyramidal neurons significantly increased tonic currents. Surprisingly, the increase of tonic inhibition was accompanied by a dramatic reduction of the phasic inhibition, suggesting a possible homeostatic regulation of the total inhibition. Overexpressing the α6 subunit alone induced an up-regulation of δ subunit expression and suppressed phasic inhibition similar to overexpressing the α6β3δ subunits. Interestingly, blocking all GABAA receptors after overexpressing α6β3δ receptors could not restore the synaptic GABAergic transmission, suggesting that receptor activation is not required for the homeostatic interplay. Furthermore, insertion of a gephyrin-binding-site (GBS) into the α6 and δ subunits recruited α6(GBS)β3δ(GBS) receptors to postsynaptic sites but failed to rescue synaptic GABAergic transmission. Thus, it is not the positional effect of extrasynaptic α6β3δ receptors that causes the down-regulation of phasic inhibition. Overexpressing α5β3γ2 subunits similarly reduced synaptic GABAergic transmission. We propose a working model that both synaptic and extrasynaptic GABAA receptors may compete for limited receptor slots on the plasma membrane to maintain a homeostatic range of the total inhibition.
Collapse
Affiliation(s)
- Xia Wu
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Lanting Huang
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and; the Institutes of Brain Science and State Key Laboratory for Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Zheng Wu
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Ce Zhang
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Dongyun Jiang
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Yuting Bai
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Yun Wang
- the Institutes of Brain Science and State Key Laboratory for Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Gong Chen
- From the Department of Biology, The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802 and.
| |
Collapse
|
21
|
Frola E, Patrizi A, Goetz T, Medrihan L, Petrini EM, Barberis A, Wulff P, Wisden W, Sassoè-Pognetto M. Synaptic competition sculpts the development of GABAergic axo-dendritic but not perisomatic synapses. PLoS One 2013; 8:e56311. [PMID: 23457547 PMCID: PMC3572971 DOI: 10.1371/journal.pone.0056311] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 01/11/2013] [Indexed: 11/24/2022] Open
Abstract
The neurotransmitter GABA regulates many aspects of inhibitory synapse development. We tested the hypothesis that GABAA receptors (GABAARs) work together with the synaptic adhesion molecule neuroligin 2 (NL2) to regulate synapse formation in different subcellular compartments. We investigated mice (“γ2 knockdown mice”) with an engineered allele of the GABAAR γ2 subunit gene which produced a mosaic expression of synaptic GABAARs in neighboring neurons, causing a strong imbalance in synaptic inhibition. Deletion of the γ2 subunit did not abolish synapse formation or the targeting of NL2 to distinct types of perisomatic and axo-dendritic contacts. Thus synaptic localization of NL2 does not require synaptic GABAARs. However, loss of the γ2 subunit caused a selective decrease in the number of axo-dendritic synapses on cerebellar Purkinje cells and cortical pyramidal neurons, whereas perisomatic synapses were not significantly affected. Notably, γ2-positive cells had increased axo-dendritic innervation compared with both γ2-negative and wild-type counterparts. Moreover heterologous synapses on spines, that are found after total deletion of GABAARs from all Purkinje cells, were rare in cerebella of γ2 knockdown mice. These findings reveal a selective role of γ2 subunit-containing GABAARs in regulating synapse development in distinct subcellular compartments, and support the hypothesis that the refinement of axo-dendritic synapses is regulated by activity-dependent competition between neighboring neurons.
Collapse
Affiliation(s)
- Elena Frola
- Department of Neurosciences, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Annarita Patrizi
- Department of Neurosciences, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
| | - Thomas Goetz
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - Lucian Medrihan
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Enrica Maria Petrini
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Andrea Barberis
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
| | - Peer Wulff
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
| | - William Wisden
- Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
- * E-mail: (WW); (MSP)
| | - Marco Sassoè-Pognetto
- Department of Neurosciences, University of Turin, and National Institute of Neuroscience-Italy, Torino, Italy
- * E-mail: (WW); (MSP)
| |
Collapse
|
22
|
Type IV pilus protein PilA of Pseudomonas aeruginosa modulates calcium signaling through binding the calcium-modulating cyclophilin ligand. J Infect Chemother 2013; 19:653-64. [DOI: 10.1007/s10156-012-0536-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 12/06/2012] [Indexed: 01/07/2023]
|
23
|
Yamamoto Y, Sakisaka T. Molecular Machinery for Insertion of Tail-Anchored Membrane Proteins into the Endoplasmic Reticulum Membrane in Mammalian Cells. Mol Cell 2012; 48:387-97. [DOI: 10.1016/j.molcel.2012.08.028] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 07/02/2012] [Accepted: 08/27/2012] [Indexed: 11/27/2022]
|
24
|
Luscher B, Fuchs T, Kilpatrick CL. GABAA receptor trafficking-mediated plasticity of inhibitory synapses. Neuron 2011; 70:385-409. [PMID: 21555068 DOI: 10.1016/j.neuron.2011.03.024] [Citation(s) in RCA: 316] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2011] [Indexed: 12/22/2022]
Abstract
Proper developmental, neural cell-type-specific, and activity-dependent regulation of GABAergic transmission is essential for virtually all aspects of CNS function. The number of GABA(A) receptors in the postsynaptic membrane directly controls the efficacy of GABAergic synaptic transmission. Thus, regulated trafficking of GABA(A) receptors is essential for understanding brain function in both health and disease. Here we summarize recent progress in the understanding of mechanisms that allow dynamic adaptation of cell surface expression and postsynaptic accumulation and function of GABA(A) receptors. This includes activity-dependent and cell-type-specific changes in subunit gene expression, assembly of subunits into receptors, as well as exocytosis, endocytic recycling, diffusion dynamics, and degradation of GABA(A) receptors. In particular, we focus on the roles of receptor-interacting proteins, scaffold proteins, synaptic adhesion proteins, and enzymes that regulate the trafficking and function of receptors and associated proteins. In addition, we review neuropeptide signaling pathways that affect neural excitability through changes in GABA(A)R trafficking.
Collapse
Affiliation(s)
- Bernhard Luscher
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.
| | | | | |
Collapse
|
25
|
Lim JH, Kim TY, Kim WH, Park JW. CAML promotes prolactin-dependent proliferation of breast cancer cells by facilitating prolactin receptor signaling pathways. Breast Cancer Res Treat 2010; 130:19-27. [DOI: 10.1007/s10549-010-1274-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 11/17/2010] [Indexed: 11/24/2022]
|
26
|
Smith KR, Kittler JT. The cell biology of synaptic inhibition in health and disease. Curr Opin Neurobiol 2010; 20:550-6. [PMID: 20650630 DOI: 10.1016/j.conb.2010.06.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 06/08/2010] [Accepted: 06/10/2010] [Indexed: 11/24/2022]
Abstract
Fast synaptic inhibition is largely mediated by GABA(A) receptors (GABA(A)Rs), ligand-gated chloride channels that play an essential role in the control of cell and network activity in the brain. Recent work has demonstrated that the delivery, number and stability of GABA(A)Rs at inhibitory synapses play a key role in the dynamic regulation of inhibitory synaptic efficacy and plasticity. The regulatory pathways essential for the fine-tuning of synaptic inhibition have also emerged as key sites of vulnerability during pathological changes in cell excitability in disease states.
Collapse
Affiliation(s)
- Katharine R Smith
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | | |
Collapse
|
27
|
Zhang W, Savelieva KV, Suwanichkul A, Small DL, Kirkpatrick LL, Xu N, Lanthorn TH, Ye GL. Transmembrane and ubiquitin-like domain containing 1 (Tmub1) regulates locomotor activity and wakefulness in mice and interacts with CAMLG. PLoS One 2010; 5:e11261. [PMID: 20582322 PMCID: PMC2889838 DOI: 10.1371/journal.pone.0011261] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 05/19/2010] [Indexed: 12/14/2022] Open
Abstract
Tmub1 (C7orf21/HOPS) encodes a protein containing a ubiquitin-like domain. Tmub1 is highly expressed in the nervous system. To study its physiological function, we generated mice with Tmub1 deleted by homologous recombination. The knockout mice were grossly normal and viable. In a comprehensive behavioral testing battery, the only knockout phenotype displayed was a strong increase in home cage locomotor activity during the dark phase (subjective day) of the light∶dark (L∶D) cycle. There were no changes in activity during the light period. There were no changes in locomotor activity observed in other assays, e.g. novel open-field. The increase in dark phase locomotor activity persisted during a seven day D∶D (complete darkness) challenge, and remained largely confined to the normally dark period. Telemetric recording in freely moving subjects for one 24 hr L∶D cycle, revealed the same increase in locomotor activity in the dark phase. In addition, EEG analysis showed that the knockout mice exhibited increased waking and decreased NREM & REM times during the dark phase, but the EEG was otherwise normal. Using lacZ as a reporter we found Tmub1 expression prominent in a few brain structures including the thalamus, a region known to drive wakefulness and arousal via its projections to the cortex. We identified calcium modulating cyclophilin ligand CAMLG/CAML as a binding partner by a yeast two-hybrid screen of a brain library. The interaction of Tmub1 and CAMLG was confirmed by co-immunoprecipitation assays in HEK cells. The two proteins were also found to be co-localized to the cytoplasm when expressed in HEK cells. Both Tmub1 and CAMLG have been recently described in the regulation of membrane trafficking of specific receptors. Taken together our results implicate Tmub1 in the regulation of locomotor activity and wakefulness and suggest that Tmub1 binds to and functions together with CAMLG.
Collapse
Affiliation(s)
- Wandong Zhang
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Katerina V. Savelieva
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Adisak Suwanichkul
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Daniel L. Small
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Laura L. Kirkpatrick
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Nianhua Xu
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Thomas H. Lanthorn
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
| | - Gui-Lan Ye
- Neuroscience Research, Lexicon Pharmaceuticals Inc., The Woodlands, Texas, United States of America
- * E-mail:
| |
Collapse
|
28
|
Peng Z, Shi T, Ma D. RNF122: a novel ubiquitin ligase associated with calcium-modulating cyclophilin ligand. BMC Cell Biol 2010; 11:41. [PMID: 20553626 PMCID: PMC2905333 DOI: 10.1186/1471-2121-11-41] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 06/17/2010] [Indexed: 04/03/2023] Open
Abstract
Background RNF122 is a recently discovered RING finger protein that is associated with HEK293T cell viability and is overexpressed in anaplastic thyroid cancer cells. RNF122 owns a RING finger domain in C terminus and transmembrane domain in N terminus. However, the biological mechanism underlying RNF122 action remains unknown. Results In this study, we characterized RNF122 both biochemically and intracellularly in order to gain an understanding of its biological role. RNF122 was identified as a new ubiquitin ligase that can ubiquitinate itself and undergoes degradation in a RING finger-dependent manner. From a yeast two-hybrid screen, we identified calcium-modulating cyclophilin ligand (CAML) as an RNF122-interacting protein. To examine the interaction between CAML and RNF122, we performed co-immunoprecipitation and colocalization experiments using intact cells. What is more, we found that CAML is not a substrate of ubiquitin ligase RNF122, but that, instead, it stabilizes RNF122. Conclusions RNF122 can be characterized as a C3H2C3-type RING finger-containing E3 ubiquitin ligase localized to the ER. RNF122 promotes its own degradation in a RING finger-and proteasome-dependent manner. RNF122 interacts with CAML, and its E3 ubiquitin ligase activity was noted to be dependent on the RING finger domain.
Collapse
Affiliation(s)
- Zhi Peng
- Chinese National Human Genome Center, #3-707 North YongChang Road BDA, Beijing 100176, PR China
| | | | | |
Collapse
|
29
|
CAML does not modulate tetherin-mediated restriction of HIV-1 particle release. PLoS One 2010; 5:e9005. [PMID: 20126395 PMCID: PMC2814849 DOI: 10.1371/journal.pone.0009005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 01/13/2010] [Indexed: 11/30/2022] Open
Abstract
Background Tetherin/BST-2 is a recently-identified potent restriction factor in human cells that restricts HIV particle release following particle formation and budding at the plasma membrane. Vpu counteracts tetherin's restriction of particle release in a manner that has not yet been fully defined. We recently identified calcium-modulating cyclophilin ligand (CAML) as a Vpu-interacting protein that also restricts particle release. We hypothesized that CAML may act to enhance tetherin-mediated restriction of particle release and thereby explain how two distinct factors could be responsible for Vpu-responsive restriction. Methodology/Principal Findings Endogenous levels of tetherin in human cells correlated well with their restriction pattern and responsiveness to Vpu, while levels of cellular CAML protein did not. Tetherin but not CAML was inducible by interferon in a wide variety of human cells. Stable depletion of human CAML in restrictive HeLa cells had no effect on cell surface levels of tetherin, and failed to relieve tetherin-mediated restriction. Stable depletion of tetherin from HeLa cells, in contrast, rendered HeLa cells permissive and Vpu-unresponsive. Tetherin but not CAML expression in permissive human cells rendered them restrictive and Vpu responsive. Depletion of CAML had no influence on cell surface levels of tetherin. Conclusions/Significance We conclude that tetherin restricts particle release and does not require CAML for this effect. Furthermore, these results do not support a major role for CAML in restricting HIV particle release in human cells.
Collapse
|
30
|
Morot-Gaudry-Talarmain Y. Physical and functional interactions of cyclophilin B with neuronal actin and peroxiredoxin-1 are modified by oxidative stress. Free Radic Biol Med 2009; 47:1715-30. [PMID: 19766713 DOI: 10.1016/j.freeradbiomed.2009.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 08/26/2009] [Accepted: 09/14/2009] [Indexed: 12/29/2022]
Abstract
Presynaptic actin was identified as a new Torpedo cyclophilin B partner captured in pull-down experiments and by coimmunoprecipitation. The cyclophilin B-actin pull-down interaction was insensitive to the blockade of peptidyl cis/trans prolyl isomerase and calcineurin activities and to the latrunculin A- and jasplakinolide-mediated perturbation of F-actin polymerization. Conversely, it was reduced by ATP and stimulated by a low Cu(2+) treatment of synaptosomes and by acrolydan-conjugated cyclophilin B. This Cu(2+)-induced stress, in parallel, stimulates the formation of GSH adducts with cysteines of synaptosomal actin followed by its deglutathionylation and its dimerization in the presence of higher Cu(2+) concentrations. The reversibility of the thiol processing of actin occurred in the same range of Cu(2+) concentrations that mediated a stronger cyclophilin B-actin interaction, suggesting cyclophilin B participation in antioxidant processes. Among 2-Cys-peroxiredoxin isoforms, mainly peroxiredoxin-1 was found in cell bodies and nerve endings. Functionally, both Torpedo and human peroxiredoxin-1 were activated in vitro by Torpedo cyclophilin B. Moreover, cyclophilin B, like thioredoxins, maintained an H(2)O(2)-dependent peroxidase activity of peroxiredoxin-1 in the presence of dithiothreitol. Thus, the monocysteinic Torpedo cyclophilin B is able to sustain peroxiredoxin-1 activity and might be involved in the presynaptic defense against oxidative stress affecting G-actin posttranslational changes and its redox signaling in nerve ending compartments.
Collapse
Affiliation(s)
- Yvette Morot-Gaudry-Talarmain
- Laboratoire de Neurobiologie Cellulaire et Moléculaire-UPR9040, CNRS, Institut de Neurobiologie Alfred Fessard-FRC2118, Gif sur Yvette, F-91198, France.
| |
Collapse
|
31
|
Effect of calcium-modulating cyclophilin ligand on human immunodeficiency virus type 1 particle release and cell surface expression of tetherin. J Virol 2009; 83:13032-6. [PMID: 19793820 DOI: 10.1128/jvi.01786-09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) accessory protein Vpu enhances virus particle release by counteracting a host factor that retains virions at the surfaces of infected cells. It was recently demonstrated that cellular protein BST-2/CD317/Tetherin restricts HIV-1 release in a Vpu-dependent manner. Calcium-modulating cyclophilin ligand (CAML) was also proposed to be involved in this process. We investigated whether CAML is involved in cell surface expression of Tetherin. Here, we show that CAML overexpression in permissive Cos-7 cells or CAML depletion in restrictive HeLa cells has no effect on HIV-1 release or on Tetherin surface expression, indicating that CAML is not required for Tetherin-mediated restriction of HIV-1 release.
Collapse
|
32
|
Tyagarajan SK, Fritschy JM. GABA(A) receptors, gephyrin and homeostatic synaptic plasticity. J Physiol 2009; 588:101-6. [PMID: 19752109 DOI: 10.1113/jphysiol.2009.178517] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Homeostatic synaptic plasticity describes the changes in synapse gain and function that occur in response to global changes in neuronal activity to maintain the stability of neuronal networks. In this review, we argue that a coordinated regulation of excitatory and inhibitory synaptic transmission is essential for maintaining CNS function while allowing both global and local changes in synaptic strength and connectivity. Therefore, we postulate that homeostatic synaptic plasticity depends on signalling cascades regulating in parallel the efficacy of glutamatergic and GABAergic transmission. Since neurotransmitter receptors interact closely with scaffolding proteins in the postsynaptic density, this coordinated regulation of excitatory and inhibitory synaptic transmission probably involves posttranslational modifications of scaffolding proteins, which in turn modulate local synaptic function. Here we review the current state of knowledge on the regulation of GABA(A) receptors and their main scaffolding protein gephyrin by posttranslational modifications; we outline future lines of research that might contribute to furthering our understanding of the molecular mechanisms regulating GABAergic synapse function and homeostatic plasticity.
Collapse
Affiliation(s)
- Shiva K Tyagarajan
- University of Zurich, Institute of Pharmacology and Toxicology, Winterhurerstrasse 190, CH-8057 Zurich, Switzerland
| | | |
Collapse
|
33
|
Charych EI, Liu F, Moss SJ, Brandon NJ. GABA(A) receptors and their associated proteins: implications in the etiology and treatment of schizophrenia and related disorders. Neuropharmacology 2009; 57:481-95. [PMID: 19631671 DOI: 10.1016/j.neuropharm.2009.07.027] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 07/02/2009] [Accepted: 07/13/2009] [Indexed: 02/05/2023]
Abstract
Gamma-aminobutyric acid type A (GABA(A)) receptors play an important role in mediating fast synaptic inhibition in the brain. They are ubiquitously expressed in the CNS and also represent a major site of action for clinically relevant drugs. Recent technological advances have greatly clarified the molecular and cellular roles played by distinct GABA(A) receptor subunit classes and isoforms in normal brain function. At the same time, postmortem and genetic studies have linked neuropsychiatric disorders including schizophrenia and bipolar disorder with GABAergic neurotransmission and various specific GABA(A) receptor subunits, while evidence implicating GABA(A)R-associated proteins is beginning to emerge. In this review we discuss the mounting genetic, molecular, and cellular evidence pointing toward a role for GABA(A) receptor heterogeneity in both schizophrenia etiology and therapeutic development. Finally, we speculate on the relationship between schizophrenia-related disorders and selected GABA(A) receptor associated proteins, key regulators of GABA(A) receptor trafficking, targeting, clustering, and anchoring that often carry out these functions in a subtype-specific manner.
Collapse
Affiliation(s)
- Erik I Charych
- Wyeth Research, Neuroscience Discovery, Princeton NJ 08852, USA.
| | | | | | | |
Collapse
|
34
|
Guang W, Kim KC, Lillehoj EP. MUC1 mucin interacts with calcium-modulating cyclophilin ligand. Int J Biochem Cell Biol 2008; 41:1354-60. [PMID: 19135167 DOI: 10.1016/j.biocel.2008.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Revised: 12/01/2008] [Accepted: 12/08/2008] [Indexed: 11/25/2022]
Abstract
MUC1 is an integral membrane glycoprotein expressed on epithelial and hematopoietic cells with a COOH-terminus (CT) that mediates intracellular signal transduction. To better understand MUC1-dependent signaling, we searched for proteins binding to its CT using the yeast two-hybrid system with the MUC1 CT as bait and a human epithelial cell cDNA library as prey. Of the six positive clones identified, all encoded calcium-modulating cyclophilin ligand (CAML). The MUC1 CT interacted with CAML in transformed yeast cells as revealed by growth on selective media and in situ X-alpha-galactosidase activity. Binding of the MUC1 CT to CAML in human epithelial cells was confirmed by reciprocal coimmunoprecipitations, confocal microscopy, protein crosslinking, and coupled transcription/translation analyses. By deletion mutagenesis, the NH(2)-terminus of CAML was responsible for binding to the MUC1 CT. Finally, transfection of cells with plasmids encoding MUC1 and CAML increased intracellular calcium levels compared with cells transfected with either plasmid alone, suggesting a possible biological significance of the MUC1-CAML interaction.
Collapse
Affiliation(s)
- Wei Guang
- Department of Pediatrics, University of Maryland School of Medicine, 655 W. Baltimore St., BRB 13-029, Baltimore, MD 21201, United States
| | | | | |
Collapse
|