1
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Erzurumlu Y, Dogan HK, Catakli D. New mode of action of curcumin on prostate cancer cells: Modulation of endoplasmic reticulum-associated degradation mechanism and estrogenic signaling. J Biochem Mol Toxicol 2024; 38:e23636. [PMID: 38229314 DOI: 10.1002/jbt.23636] [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: 01/22/2023] [Revised: 11/25/2023] [Accepted: 12/20/2023] [Indexed: 01/18/2024]
Abstract
Prostate cancer is leading to cancer-related mortality in numerous men each year worldwide. While there are several treatment options, acquired drug resistance mostly limits the success of treatments. Therefore, there is a need for the development of innovative treatments. Curcumin is one of the bioactive polyphenolic ingredients identified in turmeric and has numerous biological activities, such as anti-inflammatory and anticancer. In the present study, we investigated the effect of curcumin on the ER-associated degradation (ERAD) and estrogenic signaling in prostate cancer cells. The antiproliferative effect of curcumin on human androgen-dependent prostate cancer cell lines LNCaP and VCaP was estimated by WST-1 assay. Morphological alterations were investigated with an inverted microscope. We investigated the effect of curcumin on ERAD and estrogen signaling proteins by immunoblotting assay. To evaluate the impact of curcumin on endoplasmic reticulum (ER) protein quality-related, the expression level of 32 genes was analyzed by quantitative reverse transcription polymerase chain reaction. The nuclear translocation of estrogen receptor was examined by nuclear fractionation and immunofluorescence microscopy. We found that curcumin effectively reduced the proliferation rates of LNCaP and VCaP cells. ERAD proteins; Hrd1, gp78, p97/VCP, Ufd1 and Npl4 were strongly induced by curcumin. Also, the steady-state level of polyubiquitin was increased in a dose-dependent manner in both cell lines. Curcumin administration remarkably decreased the protein levels of estrogen receptor-alfa (Erα), whereas estrogen receptor-beta unaffected. Additionally, curcumin strongly restricted the nuclear translocation of Erα. Present data suggest that curcumin may be effectively used in therapeutic approaches associated with the targeting ER protein quality control mechanism and modulation of estrogen signaling in prostate cancer.
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Affiliation(s)
- Yalcin Erzurumlu
- Department of Biochemistry, Faculty of Pharmacy, Suleyman Demirel University, Isparta, Turkey
| | - Hatice Kubra Dogan
- Department of Bioengineering, Institute of Science, Suleyman Demirel University, Isparta, Turkey
| | - Deniz Catakli
- Department of Pharmacology, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey
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2
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Chu S, Xie X, Payan C, Stochaj U. Valosin containing protein (VCP): initiator, modifier, and potential drug target for neurodegenerative diseases. Mol Neurodegener 2023; 18:52. [PMID: 37545006 PMCID: PMC10405438 DOI: 10.1186/s13024-023-00639-y] [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: 02/20/2023] [Accepted: 06/27/2023] [Indexed: 08/08/2023] Open
Abstract
The AAA+ ATPase valosin containing protein (VCP) is essential for cell and organ homeostasis, especially in cells of the nervous system. As part of a large network, VCP collaborates with many cofactors to ensure proteostasis under normal, stress, and disease conditions. A large number of mutations have revealed the importance of VCP for human health. In particular, VCP facilitates the dismantling of protein aggregates and the removal of dysfunctional organelles. These are critical events to prevent malfunction of the brain and other parts of the nervous system. In line with this idea, VCP mutants are linked to the onset and progression of neurodegeneration and other diseases. The intricate molecular mechanisms that connect VCP mutations to distinct brain pathologies continue to be uncovered. Emerging evidence supports the model that VCP controls cellular functions on multiple levels and in a cell type specific fashion. Accordingly, VCP mutants derail cellular homeostasis through several mechanisms that can instigate disease. Our review focuses on the association between VCP malfunction and neurodegeneration. We discuss the latest insights in the field, emphasize open questions, and speculate on the potential of VCP as a drug target for some of the most devastating forms of neurodegeneration.
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Affiliation(s)
- Siwei Chu
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Xinyi Xie
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Carla Payan
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, HG3 1Y6, Canada.
- Quantitative Life Sciences Program, McGill University, Montreal, Canada.
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3
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Halpin JC, Whitney D, Rigoldi F, Sivaraman V, Singer A, Keating AE. Molecular determinants of TRAF6 binding specificity suggest that native interaction partners are not optimized for affinity. Protein Sci 2022; 31:e4429. [PMID: 36305766 PMCID: PMC9597381 DOI: 10.1002/pro.4429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/14/2022] [Accepted: 08/19/2022] [Indexed: 11/25/2022]
Abstract
TRAF6 is an adaptor protein involved in signaling pathways that are essential for development and the immune system. It participates in many protein-protein interactions, some of which are mediated by the C-terminal MATH domain, which binds to short peptide segments containing the motif PxExx[FYWHDE], where x is any amino acid. Blocking MATH domain interactions is associated with favorable effects in various disease models. To better define TRAF6 MATH domain binding preferences, we screened a combinatorial library using bacterial cell-surface peptide display. We identified 236 of the best TRAF6-interacting peptides and a set of 1,200 peptides that match the sequence PxE but do not bind TRAF6 MATH. The peptides that were most enriched in the screen bound TRAF6 tighter than previously measured native peptides. To better understand the structural basis for TRAF6 interaction preferences, we built all-atom structural models of the MATH domain in complex with high-affinity binders and nonbinders identified in the screen. We identified favorable interactions for motif features in binders as well as negative design elements distributed across the motif that can disfavor or preclude binding. Searching the human proteome revealed that the most biologically relevant TRAF6 motif matches occupy a different sequence space from the best hits discovered in combinatorial library screening, suggesting that native interactions are not optimized for affinity. Our experimentally determined binding preferences and structural models support the design of peptide-based interaction inhibitors with higher affinities than endogenous TRAF6 ligands.
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Affiliation(s)
| | | | | | | | | | - Amy E. Keating
- MIT Department of BiologyCambridgeMassachusettsUSA
- MIT Department of Biological EngineeringCambridgeMassachusettsUSA
- Koch Institute for Integrative Cancer ResearchCambridgeMassachusettsUSA
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4
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Fenech EJ, Ben-Dor S, Schuldiner M. Double the Fun, Double the Trouble: Paralogs and Homologs Functioning in the Endoplasmic Reticulum. Annu Rev Biochem 2021; 89:637-666. [PMID: 32569522 DOI: 10.1146/annurev-biochem-011520-104831] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The evolution of eukaryotic genomes has been propelled by a series of gene duplication events, leading to an expansion in new functions and pathways. While duplicate genes may retain some functional redundancy, it is clear that to survive selection they cannot simply serve as a backup but rather must acquire distinct functions required for cellular processes to work accurately and efficiently. Understanding these differences and characterizing gene-specific functions is complex. Here we explore different gene pairs and families within the context of the endoplasmic reticulum (ER), the main cellular hub of lipid biosynthesis and the entry site for the secretory pathway. Focusing on each of the ER functions, we highlight specificities of related proteins and the capabilities conferred to cells through their conservation. More generally, these examples suggest why related genes have been maintained by evolutionary forces and provide a conceptual framework to experimentally determine why they have survived selection.
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Affiliation(s)
- Emma J Fenech
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel;
| | - Shifra Ben-Dor
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel;
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5
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Fenech EJ, Lari F, Charles PD, Fischer R, Laétitia-Thézénas M, Bagola K, Paton AW, Paton JC, Gyrd-Hansen M, Kessler BM, Christianson JC. Interaction mapping of endoplasmic reticulum ubiquitin ligases identifies modulators of innate immune signalling. eLife 2020; 9:e57306. [PMID: 32614325 PMCID: PMC7332293 DOI: 10.7554/elife.57306] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/11/2020] [Indexed: 12/25/2022] Open
Abstract
Ubiquitin ligases (E3s) embedded in the endoplasmic reticulum (ER) membrane regulate essential cellular activities including protein quality control, calcium flux, and sterol homeostasis. At least 25 different, transmembrane domain (TMD)-containing E3s are predicted to be ER-localised, but for most their organisation and cellular roles remain poorly defined. Using a comparative proteomic workflow, we mapped over 450 protein-protein interactions for 21 stably expressed, full-length E3s. Bioinformatic analysis linked ER-E3s and their interactors to multiple homeostatic, regulatory, and metabolic pathways. Among these were four membrane-embedded interactors of RNF26, a polytopic E3 whose abundance is auto-regulated by ubiquitin-proteasome dependent degradation. RNF26 co-assembles with TMEM43, ENDOD1, TMEM33 and TMED1 to form a complex capable of modulating innate immune signalling through the cGAS-STING pathway. This RNF26 complex represents a new modulatory axis of STING and innate immune signalling at the ER membrane. Collectively, these data reveal the broad scope of regulation and differential functionalities mediated by ER-E3s for both membrane-tethered and cytoplasmic processes.
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Affiliation(s)
- Emma J Fenech
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - Federica Lari
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - Philip D Charles
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of OxfordOxfordUnited Kingdom
| | - Roman Fischer
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of OxfordOxfordUnited Kingdom
| | - Marie Laétitia-Thézénas
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of OxfordOxfordUnited Kingdom
| | - Katrin Bagola
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - Adrienne W Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of AdelaideAdelaideAustralia
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of AdelaideAdelaideAustralia
| | - Mads Gyrd-Hansen
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - Benedikt M Kessler
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, University of OxfordOxfordUnited Kingdom
- Chinese Academy of Medical Sciences Oxford Institute, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - John C Christianson
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of OxfordOxfordUnited Kingdom
- Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Botnar Research CentreOxfordUnited Kingdom
- Oxford Centre for Translational Myeloma Research, University of Oxford, Botnar Research CentreOxfordUnited Kingdom
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6
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The evolving role of ubiquitin modification in endoplasmic reticulum-associated degradation. Biochem J 2017; 474:445-469. [PMID: 28159894 DOI: 10.1042/bcj20160582] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/12/2016] [Accepted: 12/14/2016] [Indexed: 12/13/2022]
Abstract
The endoplasmic reticulum (ER) serves as a warehouse for factors that augment and control the biogenesis of nascent proteins entering the secretory pathway. In turn, this compartment also harbors the machinery that responds to the presence of misfolded proteins by targeting them for proteolysis via a process known as ER-associated degradation (ERAD). During ERAD, substrates are selected, modified with ubiquitin, removed from the ER, and then degraded by the cytoplasmic 26S proteasome. While integral membrane proteins can directly access the ubiquitination machinery that resides in the cytoplasm or on the cytoplasmic face of the ER membrane, soluble ERAD substrates within the lumen must be retrotranslocated from this compartment. In either case, nearly all ERAD substrates are tagged with a polyubiquitin chain, a modification that represents a commitment step to degrade aberrant proteins. However, increasing evidence indicates that the polyubiquitin chain on ERAD substrates can be further modified, serves to recruit ERAD-requiring factors, and may regulate the ERAD machinery. Amino acid side chains other than lysine on ERAD substrates can also be modified with ubiquitin, and post-translational modifications that affect substrate ubiquitination have been observed. Here, we summarize these data and provide an overview of questions driving this field of research.
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7
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van de Weijer ML, van Muijlwijk GH, Visser LJ, Costa AI, Wiertz EJHJ, Lebbink RJ. The E3 Ubiquitin Ligase TMEM129 Is a Tri-Spanning Transmembrane Protein. Viruses 2016; 8:v8110309. [PMID: 27854284 PMCID: PMC5127023 DOI: 10.3390/v8110309] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/03/2016] [Accepted: 11/04/2016] [Indexed: 12/20/2022] Open
Abstract
Misfolded proteins from the endoplasmic reticulum (ER) are transported back into the cytosol for degradation via the ubiquitin-proteasome system. The human cytomegalovirus protein US11 hijacks this ER-associated protein degradation (ERAD) pathway to downregulate human leukocyte antigen (HLA) class I molecules in virus-infected cells, thereby evading elimination by cytotoxic T-lymphocytes. Recently, we identified the E3 ubiquitin ligase transmembrane protein 129 (TMEM129) as a key player in this process, where interference with TMEM129 activity in human cells completely abrogates US11-mediated class I degradation. Here, we set out to further characterize TMEM129. We show that TMEM129 is a non-glycosylated protein containing a non-cleaved signal anchor sequence. By glycosylation scanning mutagenesis, we show that TMEM129 is a tri-spanning ER-membrane protein that adopts an Nexo–Ccyto orientation. This insertion in the ER membrane positions the C-terminal really interesting new gene (RING) domain of TMEM129 in the cytosol, making it available to catalyze ubiquitination reactions that are required for cytosolic degradation of secretory proteins.
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Affiliation(s)
| | - Guus H van Muijlwijk
- Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands.
| | - Linda J Visser
- Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands.
| | - Ana I Costa
- Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands.
| | - Emmanuel J H J Wiertz
- Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands.
| | - Robert Jan Lebbink
- Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands.
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8
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Kaneko M, Iwase I, Yamasaki Y, Takai T, Wu Y, Kanemoto S, Matsuhisa K, Asada R, Okuma Y, Watanabe T, Imaizumi K, Nomura Y. Genome-wide identification and gene expression profiling of ubiquitin ligases for endoplasmic reticulum protein degradation. Sci Rep 2016; 6:30955. [PMID: 27485036 PMCID: PMC4971459 DOI: 10.1038/srep30955] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 07/08/2016] [Indexed: 11/30/2022] Open
Abstract
Endoplasmic reticulum (ER)-associated degradation (ERAD) is a mechanism by which unfolded proteins that accumulate in the ER are transported to the cytosol for ubiquitin–proteasome-mediated degradation. Ubiquitin ligases (E3s) are a group of enzymes responsible for substrate selectivity and ubiquitin chain formation. The purpose of this study was to identify novel E3s involved in ERAD. Thirty-seven candidate genes were selected by searches for proteins with RING-finger motifs and transmembrane regions, which are the major features of ERAD E3s. We performed gene expression profiling for the identified E3s in human and mouse tissues. Several genes were specifically or selectively expressed in both tissues; the expression of four genes (RNFT1, RNF185, CGRRF1 and RNF19B) was significantly upregulated by ER stress. To determine the involvement of the ER stress-responsive genes in ERAD, we investigated their ER localisation, in vitro autoubiquitination activity and ER stress resistance. All were partially localised to the ER, whereas CGRRF1 did not possess E3 activity. RNFT1 and RNF185, but not CGRRF1 and RNF19B, exhibited significant resistance to ER stressor in an E3 activity-dependent manner. Thus, these genes are possible candidates for ERAD E3s.
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Affiliation(s)
- Masayuki Kaneko
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Ikuko Iwase
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Yuki Yamasaki
- Otsuka GEN Research Institute, Otsuka Pharmaceutical Co., Ltd., Tokushima 771-0192, Japan
| | - Tomoko Takai
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Yan Wu
- Department of Biochemistry, Graduate school of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Soshi Kanemoto
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Koji Matsuhisa
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Rie Asada
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Yasunobu Okuma
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, Choshi, Chiba 288-0025, Japan
| | - Takeshi Watanabe
- Otsuka GEN Research Institute, Otsuka Pharmaceutical Co., Ltd., Tokushima 771-0192, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Yausyuki Nomura
- Department of Pharmacology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
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9
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Olzmann JA, Kopito RR, Christianson JC. The mammalian endoplasmic reticulum-associated degradation system. Cold Spring Harb Perspect Biol 2013; 5:cshperspect.a013185. [PMID: 23232094 DOI: 10.1101/cshperspect.a013185] [Citation(s) in RCA: 253] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The endoplasmic reticulum (ER) is the site of synthesis for nearly one-third of the eukaryotic proteome and is accordingly endowed with specialized machinery to ensure that proteins deployed to the distal secretory pathway are correctly folded and assembled into native oligomeric complexes. Proteins failing to meet this conformational standard are degraded by ER-associated degradation (ERAD), a complex process through which folding-defective proteins are selected and ultimately degraded by the ubiquitin-proteasome system. ERAD proceeds through four tightly coupled steps involving substrate selection, dislocation across the ER membrane, covalent conjugation with polyubiquitin, and proteasomal degradation. The ERAD machinery shows a modular organization with central ER membrane-embedded ubiquitin ligases linking components responsible for recognition in the ER lumen to the ubiquitin-proteasome system in the cytoplasm. The core ERAD machinery is highly conserved among eukaryotes and much of our basic understanding of ERAD organization has been derived from genetic and biochemical studies of yeast. In this article we discuss how the core ERAD machinery is organized in mammalian cells.
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Affiliation(s)
- James A Olzmann
- Department of Biology, Stanford University, Stanford, California 94305, USA
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10
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Misfolded proteins recognition strategies of E3 ubiquitin ligases and neurodegenerative diseases. Mol Neurobiol 2012; 47:302-12. [PMID: 23001884 DOI: 10.1007/s12035-012-8351-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 09/12/2012] [Indexed: 12/31/2022]
Abstract
Impairment in the clearance of misfolded proteins by functional proteins leads to various late-onset neurodegenerative diseases. Cell applies a strict quality control mechanism against malfunctioned proteins which may generate cellular proteoxicity. Under proteotoxic insults, cells immediately adopt two major approaches to either refold the misfolded proteinaceous species or degrade the unmanageable candidates. However, the main cellular proteostasis quality control mechanism is not clear. It is therefore important to understand the events and cellular pathways, which are implicated in the clearance of recalcitrant proteins. Ubiquitin proteasome system manages intracellular protein degradation. In this process, E3 ubiquitin ligase enzyme provides specificity for recognition of client proteins. In this review, we summarize various molecular approaches governed by E3 ubiquitin ligases in the degradation of aberrant proteins. A clear understanding of E3 ubiquitin ligases can offer a well tractable therapeutic approach against neurodegenerative diseases.
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11
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Nakamura N. The Role of the Transmembrane RING Finger Proteins in Cellular and Organelle Function. MEMBRANES 2011; 1:354-93. [PMID: 24957874 PMCID: PMC4021871 DOI: 10.3390/membranes1040354] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 11/24/2011] [Accepted: 12/05/2011] [Indexed: 01/08/2023]
Abstract
A large number of RING finger (RNF) proteins are present in eukaryotic cells and the majority of them are believed to act as E3 ubiquitin ligases. In humans, 49 RNF proteins are predicted to contain transmembrane domains, several of which are specifically localized to membrane compartments in the secretory and endocytic pathways, as well as to mitochondria and peroxisomes. They are thought to be molecular regulators of the organization and integrity of the functions and dynamic architecture of cellular membrane and membranous organelles. Emerging evidence has suggested that transmembrane RNF proteins control the stability, trafficking and activity of proteins that are involved in many aspects of cellular and physiological processes. This review summarizes the current knowledge of mammalian transmembrane RNF proteins, focusing on their roles and significance.
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Affiliation(s)
- Nobuhiro Nakamura
- Department of Biological Sciences, Tokyo Institute of Technology, 4259-B13 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
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12
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Claessen JHL, Kundrat L, Ploegh HL. Protein quality control in the ER: balancing the ubiquitin checkbook. Trends Cell Biol 2011; 22:22-32. [PMID: 22055166 DOI: 10.1016/j.tcb.2011.09.010] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/23/2011] [Accepted: 09/27/2011] [Indexed: 11/30/2022]
Abstract
Protein maturation in the endoplasmic reticulum (ER) is subject to stringent quality control. Terminally misfolded polypeptides are usually ejected into the cytoplasm and targeted for destruction by the proteasome. Ubiquitin conjugation is essential for both extraction and proteolysis. We discuss the role of the ubiquitin conjugation machinery in this pathway and focus on the role of ubiquitin ligase complexes as gatekeepers for membrane passage. We then examine the type of ubiquitin modification applied to the misfolded ER protein and the role of de-ubiquitylating enzymes in the extraction of proteins from the ER.
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Affiliation(s)
- Jasper H L Claessen
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
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13
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Lu JP, Wang Y, Sliter DA, Pearce MMP, Wojcikiewicz RJH. RNF170 protein, an endoplasmic reticulum membrane ubiquitin ligase, mediates inositol 1,4,5-trisphosphate receptor ubiquitination and degradation. J Biol Chem 2011; 286:24426-33. [PMID: 21610068 DOI: 10.1074/jbc.m111.251983] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Inositol 1,4,5-trisphosphate (IP(3)) receptors are endoplasmic reticulum membrane calcium channels that, upon activation, are degraded via the ubiquitin-proteasome pathway. While searching for novel mediators of IP(3) receptor processing, we discovered that RNF170, an uncharacterized RING domain-containing protein, associates rapidly with activated IP(3) receptors. RNF170 is predicted to have three membrane-spanning helices, is localized to the ER membrane, and possesses ubiquitin ligase activity. Depletion of endogenous RNF170 by RNA interference inhibited stimulus-induced IP(3) receptor ubiquitination, and degradation and overexpression of a catalytically inactive RNF170 mutant suppressed stimulus-induced IP(3) receptor processing. A substantial proportion of RNF170 is constitutively associated with the erlin1/2 (SPFH1/2) complex, which has been shown previously to bind to IP(3) receptors immediately after their activation. Depletion of RNF170 did not affect the binding of the erlin1/2 complex to stimulated IP(3) receptors, whereas erlin1/2 complex depletion inhibited RNF170 binding. These results suggest a model in which the erlin1/2 complex recruits RNF170 to activated IP(3) receptors where it mediates IP(3) receptor ubiquitination. Thus, RNF170 plays an essential role in IP(3) receptor processing via the ubiquitin-proteasome pathway.
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Affiliation(s)
- Justine P Lu
- Department of Pharmacology, State University of New York Upstate Medical University, Syracuse, New York 13210, USA
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14
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Yao I, Takao K, Miyakawa T, Ito S, Setou M. Synaptic E3 ligase SCRAPPER in contextual fear conditioning: extensive behavioral phenotyping of Scrapper heterozygote and overexpressing mutant mice. PLoS One 2011; 6:e17317. [PMID: 21390313 PMCID: PMC3044740 DOI: 10.1371/journal.pone.0017317] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 01/31/2011] [Indexed: 11/22/2022] Open
Abstract
SCRAPPER, an F-box protein coded by FBXL20, is a subunit of SCF type E3 ubiquitin ligase. SCRAPPER localizes synapses and directly binds to Rab3-interacting molecule 1 (RIM1), an essential factor for synaptic vesicle release, thus it regulates neural transmission via RIM1 degradation. A defect in SCRAPPER leads to neurotransmission abnormalities, which could subsequently result in neurodegenerative phenotypes. Because it is likely that the alteration of neural transmission in Scrapper mutant mice affect their systemic condition, we have analyzed the behavioral phenotypes of mice with decreased or increased the amount of SCRAPPER. We carried out a series of behavioral test batteries for Scrapper mutant mice. Scrapper transgenic mice overexpressing SCRAPPER in the hippocampus did not show any significant difference in every test argued in this manuscript by comparison with wild-type mice. On the other hand, heterozygotes of Scrapper knockout [SCR (+/−)] mice showed significant difference in the contextual but not cued fear conditioning test. In addition, SCR (+/−) mice altered in some tests reflecting anxiety, which implies the loss of functions of SCRAPPER in the hippocampus. The behavioral phenotypes of Scrapper mutant mice suggest that molecular degradation conferred by SCRAPPER play important roles in hippocampal-dependent fear memory formation.
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Affiliation(s)
- Ikuko Yao
- Department of Medical Chemistry, Kansai Medical University, Moriguchi, Osaka, Japan
- Mitsubishi Kagaku Institute of Life Sciences, Machida, Tokyo, Japan
- * E-mail: (IY); (MS)
| | - Keizo Takao
- Genetic Engineering and Functional Genomics Group, Frontier Technology Center, Graduate School of Medicine Kyoto University, Kyoto, Japan
- Section of Behavior Analysis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Tsuyoshi Miyakawa
- Genetic Engineering and Functional Genomics Group, Frontier Technology Center, Graduate School of Medicine Kyoto University, Kyoto, Japan
- Section of Behavior Analysis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Seiji Ito
- Department of Medical Chemistry, Kansai Medical University, Moriguchi, Osaka, Japan
| | - Mitsutoshi Setou
- Mitsubishi Kagaku Institute of Life Sciences, Machida, Tokyo, Japan
- Department of Molecular Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan
- * E-mail: (IY); (MS)
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Mehnert M, Sommer T, Jarosch E. ERAD ubiquitin ligases: multifunctional tools for protein quality control and waste disposal in the endoplasmic reticulum. Bioessays 2010; 32:905-13. [PMID: 20806269 DOI: 10.1002/bies.201000046] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In eukaryotic cells terminally misfolded proteins of the secretory pathway are retarded in the endoplasmic reticulum (ER) and subsequently degraded in a ubiquitin-proteasome-dependent manner. This highly conserved process termed ER-associated protein degradation (ERAD) ensures homeostasis in the secretory pathway by disposing faulty polypeptides and preventing their deleterious accumulation and eventual aggregation in the cell. The focus of this paper is the functional description of membrane-bound ubiquitin ligases, which are involved in all critical steps of ERAD. In the end we want to speculate on how the modular architecture of these entities ensures the specificity of substrate selection and possibly accomplishes the transport of misfolded polypeptides from the ER into the cytoplasm.
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Affiliation(s)
- Martin Mehnert
- Max-Delbrück Center for Molecular Medicine, Robert-Rössle-Str., Berlin, Germany
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Wojcikiewicz RJH, Pearce MMP, Sliter DA, Wang Y. When worlds collide: IP(3) receptors and the ERAD pathway. Cell Calcium 2009; 46:147-53. [PMID: 19709743 DOI: 10.1016/j.ceca.2009.05.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 05/01/2009] [Accepted: 05/05/2009] [Indexed: 12/13/2022]
Abstract
While cell signaling devotees tend to think of the endoplasmic reticulum (ER) as a Ca(2+) store, those who study protein synthesis tend to see it more as site for protein maturation, or even degradation when proteins do not fold properly. These two worldviews collide when inositol 1,4,5-trisphosphate (IP(3)) receptors are activated, since in addition to acting as release channels for stored ER Ca(2+), IP(3) receptors are rapidly destroyed via the ER-associated degradation (ERAD) pathway, a ubiquitination- and proteasome-dependent mechanism that clears the ER of aberrant proteins. Here we review recent studies showing that activated IP(3) receptors are ubiquitinated in an unexpectedly complex manner, and that a novel complex composed of the ER membrane proteins SPFH1 and SPFH2 (erlin 1 and 2) binds to IP(3) receptors immediately after they are activated and mediates their ERAD. Remarkably, it seems that the conformational changes that underpin channel opening make IP(3) receptors resemble aberrant proteins, which triggers their binding to the SPFH1/2 complex, their ubiquitination and extraction from the ER membrane and finally, their degradation by the proteasome. This degradation of activated IP(3) receptors by the ERAD pathway serves to reduce the sensitivity of ER Ca(2+) stores to IP(3) and may protect cells against deleterious effects of over-activation of Ca(2+) signaling pathways.
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Brodsky JL, Wojcikiewicz RJH. Substrate-specific mediators of ER associated degradation (ERAD). Curr Opin Cell Biol 2009; 21:516-21. [PMID: 19443192 DOI: 10.1016/j.ceb.2009.04.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 04/09/2009] [Accepted: 04/14/2009] [Indexed: 01/21/2023]
Abstract
Approximately one-third of newly synthesized eukaryotic proteins are targeted to the secretory pathway, which is composed of an organellar network that houses the enzymes and maintains the chemical environment required for the maturation of secreted and membrane proteins. Nevertheless, this diverse group of proteins may fail to achieve their native states and are consequently selected for ER associated degradation (ERAD). Over the past few years, significant effort has been made to dissect the components of the core ERAD machinery that is responsible for the destruction of most ERAD substrates. Interestingly, however, some ERAD substrates associate with dedicated chaperone-like proteins that target them for proteolysis or protect them from destruction. Other substrates fold and function normally but can be selected for ERAD by protein adaptors that identify and transmit regulatory cues.
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Affiliation(s)
- Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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Hashimoto-Gotoh T, Iwabe N, Tsujimura A, Takao K, Miyakawa T. KF-1 Ubiquitin Ligase: An Anxiety Suppressor. Front Neurosci 2009; 3:15-24. [PMID: 19753093 PMCID: PMC2695387 DOI: 10.3389/neuro.01.004.2009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 02/27/2009] [Indexed: 11/13/2022] Open
Abstract
Anxiety is an instinct that may have developed to promote adaptive survival by evading unnecessary danger. However, excessive anxiety is disruptive and can be a basic disorder of other psychiatric diseases such as depression. The KF-1, a ubiquitin ligase located on the endoplasmic reticulum (ER), may prevent excessive anxiety; kf-1−/− mice exhibit selectively elevated anxiety-like behavior against light or heights. It is surmised that KF-1 degrades some target proteins, responsible for promoting anxiety, through the ER-associated degradation pathway, similar to Parkin in Parkinson's disease (PD). Parkin, another ER-ubiquitin ligase, prevents the degeneration of dopaminergic neurons by degrading the target proteins responsible for PD. Molecular phylogenetic studies have revealed that the prototype of kf-1 appeared in the very early phase of animal evolution but was lost, unlike parkin, in the lineage leading up to Drosophila. Therefore, kf-1−/− mice may be a powerful tool for elucidating the molecular mechanisms involved in emotional regulation, and for screening novel anxiolytic/antidepressant compounds.
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Affiliation(s)
- Tamotsu Hashimoto-Gotoh
- Department of Biochemistry and Molecular Genetics, Research Institute for Neurological Diseases and Geriatrics, Kyoto Prefectural University of Medicine Japan
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