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Yang E, Fan X, Ye H, Sun X, Ji Q, Ding Q, Zhong S, Zhao S, Xuan C, Fang M, Ding X, Cao J. Exploring the role of ubiquitin regulatory X domain family proteins in cancers: bioinformatics insights, mechanisms, and implications for therapy. J Transl Med 2024; 22:157. [PMID: 38365777 PMCID: PMC10870615 DOI: 10.1186/s12967-024-04890-9] [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: 10/23/2023] [Accepted: 01/13/2024] [Indexed: 02/18/2024] Open
Abstract
UBXD family (UBXDF), a group of proteins containing ubiquitin regulatory X (UBX) domains, play a crucial role in the imbalance of proliferation and apoptotic in cancer. In this study, we summarised bioinformatics proof on multi-omics databases and literature on UBXDF's effects on cancer. Bioinformatics analysis revealed that Fas-associated factor 1 (FAF1) has the largest number of gene alterations in the UBXD family and has been linked to survival and cancer progression in many cancers. UBXDF may affect tumour microenvironment (TME) and drugtherapy and should be investigated in the future. We also summarised the experimental evidence of the mechanism of UBXDF in cancer, both in vitro and in vivo, as well as its application in clinical and targeted drugs. We compared bioinformatics and literature to provide a multi-omics insight into UBXDF in cancers, review proof and mechanism of UBXDF effects on cancers, and prospect future research directions in-depth. We hope that this paper will be helpful for direct cancer-related UBXDF studies.
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Affiliation(s)
- Enyu Yang
- School of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Xiaowei Fan
- School of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Haihan Ye
- School of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Xiaoyang Sun
- School of Biological Sciences, The University of Hong Kong, Hong Kong , 999077, Special Administrative Region, China
| | - Qing Ji
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Department of Head and Neck and Rare Oncology, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, 310022, China
| | - Qianyun Ding
- Department of 'A', The Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Shulian Zhong
- Zhejiang Sci-Tech University Hospital, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Shuo Zhao
- School of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Cheng Xuan
- School of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Meiyu Fang
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Department of Head and Neck and Rare Oncology, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, 310022, China.
| | - Xianfeng Ding
- School of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China.
| | - Jun Cao
- Key Laboratory of Head & Neck Cancer Translational Research of Zhejiang Province, Department of Head and Neck and Rare Oncology, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, 310022, China.
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2
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Braxton JR, Southworth DR. Structural insights of the p97/VCP AAA+ ATPase: How adapter interactions coordinate diverse cellular functionality. J Biol Chem 2023; 299:105182. [PMID: 37611827 PMCID: PMC10641518 DOI: 10.1016/j.jbc.2023.105182] [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: 05/30/2023] [Revised: 08/05/2023] [Accepted: 08/14/2023] [Indexed: 08/25/2023] Open
Abstract
p97/valosin-containing protein is an essential eukaryotic AAA+ ATPase with diverse functions including protein homeostasis, membrane remodeling, and chromatin regulation. Dysregulation of p97 function causes severe neurodegenerative disease and is associated with cancer, making this protein a significant therapeutic target. p97 extracts polypeptide substrates from macromolecular assemblies by hydrolysis-driven translocation through its central pore. Growing evidence indicates that this activity is highly coordinated by "adapter" partner proteins, of which more than 30 have been identified and are commonly described to facilitate translocation through substrate recruitment or modification. In so doing, these adapters enable critical p97-dependent functions such as extraction of misfolded proteins from the endoplasmic reticulum or mitochondria, and are likely the reason for the extreme functional diversity of p97 relative to other AAA+ translocases. Here, we review the known functions of adapter proteins and highlight recent structural and biochemical advances that have begun to reveal the diverse molecular bases for adapter-mediated regulation of p97 function. These studies suggest that the range of mechanisms by which p97 activity is controlled is vastly underexplored with significant advances possible for understanding p97 regulation by the most known adapters.
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Affiliation(s)
- Julian R Braxton
- Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, San Francisco, California, USA; Department of Biochemistry and Biophysics and Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, USA
| | - Daniel R Southworth
- Department of Biochemistry and Biophysics and Institute for Neurodegenerative Diseases, University of California, San Francisco, San Francisco, California, USA.
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3
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Zhang J, Vancea AI, Arold ST. Targeting plant UBX proteins: AI-enhanced lessons from distant cousins. TRENDS IN PLANT SCIENCE 2022; 27:1099-1108. [PMID: 35718708 DOI: 10.1016/j.tplants.2022.05.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/21/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Across all eukaryotic kingdoms, ubiquitin regulatory X (UBX) domain-containing adaptor proteins control the segregase cell division control protein 48 (CDC48), and thereby also control cellular proteostasis and adaptation. The structures and biological roles of UBX proteins in animals and fungi have garnered considerable attention. However, their counterparts in plants remain markedly understudied. Since 2021, the artificial intelligence (AI)-based algorithm AlphaFold has provided predictions of protein structural features that can be highly accurate. Predictions of the proteomes of all major model organisms are now freely accessible to the entire research community through user-friendly web interfaces. We propose that the combination of cross-kingdom comparison with AF analysis produces a wealth of testable hypotheses to inspire and guide experimental research on plant UBX domain-containing (PUX) proteins.
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Affiliation(s)
- Junrui Zhang
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Biological and Environmental Science and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia
| | - Alexandra I Vancea
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Biological and Environmental Science and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia
| | - Stefan T Arold
- King Abdullah University of Science and Technology (KAUST), Computational Bioscience Research Center (CBRC), Biological and Environmental Science and Engineering (BESE), Thuwal 23955-6900, Saudi Arabia; Centre de Biochimie Structurale, CNRS, INSERM, Université de Montpellier, 34090 Montpellier, France.
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4
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Fujisawa R, Polo Rivera C, Labib KPM. Multiple UBX proteins reduce the ubiquitin threshold of the mammalian p97-UFD1-NPL4 unfoldase. eLife 2022; 11:e76763. [PMID: 35920641 PMCID: PMC9377798 DOI: 10.7554/elife.76763] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 08/02/2022] [Indexed: 11/17/2022] Open
Abstract
The p97/Cdc48 ATPase and its ubiquitin receptors Ufd1-Npl4 are essential to unfold ubiquitylated proteins in many areas of eukaryotic cell biology. In yeast, Cdc48-Ufd1-Npl4 is controlled by a quality control mechanism, whereby substrates must be conjugated to at least five ubiquitins. Here, we show that mammalian p97-UFD1-NPL4 is governed by a complex interplay between additional p97 cofactors and the number of conjugated ubiquitins. Using reconstituted assays for the disassembly of ubiquitylated CMG (Cdc45-MCM-GINS) helicase by human p97-UFD1-NPL4, we show that the unfoldase has a high ubiquitin threshold for substrate unfolding, which can be reduced by the UBX proteins UBXN7, FAF1, or FAF2. Our data indicate that the UBX proteins function by binding to p97-UFD1-NPL4 and stabilising productive interactions between UFD1-NPL4 and K48-linked chains of at least five ubiquitins. Stimulation by UBXN7 is dependent upon known ubiquitin-binding motifs, whereas FAF1 and FAF2 use a previously uncharacterised coiled-coil domain to reduce the ubiquitin threshold of p97-UFD1-NPL4. We show that deleting the Ubnx7 and Faf1 genes impairs CMG disassembly during S-phase and mitosis and sensitises cells to reduced ubiquitin ligase activity. These findings indicate that multiple UBX proteins are important for the efficient unfolding of ubiquitylated proteins by p97-UFD1-NPL4 in mammalian cells.
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Affiliation(s)
- Ryo Fujisawa
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Cristian Polo Rivera
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Karim PM Labib
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of DundeeDundeeUnited Kingdom
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5
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Li Y, Wang J, Elzo MA, Fan H, Du K, Xia S, Shao J, Lai T, Hu S, Jia X, Lai S. Molecular Profiling of DNA Methylation and Alternative Splicing of Genes in Skeletal Muscle of Obese Rabbits. Curr Issues Mol Biol 2021; 43:1558-1575. [PMID: 34698087 PMCID: PMC8929151 DOI: 10.3390/cimb43030110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/05/2021] [Accepted: 10/07/2021] [Indexed: 12/11/2022] Open
Abstract
DNA methylation and the alternative splicing of precursor messenger RNAs (pre-mRNAs) are two important genetic modification mechanisms. However, both are currently uncharacterized in the muscle metabolism of rabbits. Thus, we constructed the Tianfu black rabbit obesity model (obese rabbits fed with a 10% high-fat diet and control rabbits from 35 days to 70 days) and collected the skeletal muscle samples from the two groups for Genome methylation sequencing and RNA sequencing. DNA methylation data showed that the promoter regions of 599 genes and gene body region of 2522 genes had significantly differential methylation rates between the two groups, of which 288 genes had differential methylation rates in promoter and gene body regions. Analysis of alternative splicing showed 555 genes involved in exon skipping (ES) patterns, and 15 genes existed in differential methylation regions. Network analysis showed that 20 hub genes were associated with ubiquitinated protein degradation, muscle development pathways, and skeletal muscle energy metabolism. Our findings suggest that the two types of genetic modification have potential regulatory effects on skeletal muscle development and provide a basis for further mechanistic studies in the rabbit.
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Affiliation(s)
- Yanhong Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Jie Wang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Mauricio A. Elzo
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA;
| | - Huimei Fan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Kun Du
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Siqi Xia
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Jiahao Shao
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Tianfu Lai
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Shenqiang Hu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Xianbo Jia
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
| | - Songjia Lai
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China; (Y.L.); (J.W.); (H.F.); (K.D.); (S.X.); (J.S.); (T.L.); (S.H.); (X.J.)
- Correspondence:
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6
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Sui X, Pan M, Li YM. Insights into the Design of p97-targeting Small Molecules from Structural Studies on p97 Functional Mechanism. Curr Med Chem 2020; 27:298-316. [PMID: 31584361 DOI: 10.2174/0929867326666191004162411] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/24/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022]
Abstract
p97, also known as valosin-containing protein or CDC48, is a member of the AAA+ protein family that is highly conserved in eukaryotes. It binds to various cofactors in the body to perform its protein-unfolding function and participates in DNA repair, degradation of subcellular membrane proteins, and protein quality control pathways, among other processes. Its malfunction can lead to many diseases, such as inclusion body myopathy, associated with Paget's disease of bone and/or frontotemporal dementia, amyotrophic lateral sclerosis disease, and others. In recent years, many small-molecule inhibitors have been deployed against p97, including bis (diethyldithiocarbamate)- copper and CB-5083, which entered the first phase of clinical tests but failed. One bottleneck in the design of p97 drugs is that its molecular mechanism remains unclear. This paper summarizes recent studies on the molecular mechanisms of p97, which may lead to insight into how the next generation of small molecules targeting p97 can be designed.
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Affiliation(s)
- Xin Sui
- Department of Chemistry, Tsinghua University, Beijing 100086, China
| | - Man Pan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, United States
| | - Yi-Ming Li
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
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7
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Abstract
p97 belongs to the functional diverse superfamily of AAA+ (ATPases Associated with diverse cellular Activities) ATPases and is characterized by an N-terminal regulatory domain and two stacked hexameric ATPase domains forming a central protein conducting channel. p97 is highly versatile and has key functions in maintaining protein homeostasis including protein quality control mechanisms like the ubiquitin proteasome system (UPS) and autophagy to disassemble polyubiquitylated proteins from chromatin, membranes, macromolecular protein complexes and aggregates which are either degraded by the proteasome or recycled. p97 can use energy derived from ATP hydrolysis to catalyze substrate unfolding and threading through its central channel. The function of p97 in a large variety of different cellular contexts is reflected by its simultaneous association with different cofactors, which are involved in substrate recognition and processing, thus leading to the formation of transient multi-protein complexes. Dysregulation in protein homeostasis and proteotoxic stress are often involved in the development of cancer and neurological diseases and targeting the UPS including p97 in cancer is a well-established pharmacological strategy. In this chapter we will describe structural and functional aspects of the p97 interactome in regulating diverse cellular processes and will discuss the role of p97 in targeted cancer therapy.
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8
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Mitochondrial MUL1 E3 ubiquitin ligase regulates Hypoxia Inducible Factor (HIF-1α) and metabolic reprogramming by modulating the UBXN7 cofactor protein. Sci Rep 2020; 10:1609. [PMID: 32005965 PMCID: PMC6994496 DOI: 10.1038/s41598-020-58484-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/18/2019] [Indexed: 11/15/2022] Open
Abstract
MUL1 is a multifunctional E3 ubiquitin ligase anchored in the outer mitochondrial membrane with its RING finger domain facing the cytoplasm. MUL1 participates in various biological pathways involved in apoptosis, mitochondrial dynamics, and innate immune response. The unique topology of MUL1 enables it to “sense” mitochondrial stress in the intermembrane mitochondrial space and convey these signals through the ubiquitination of specific cytoplasmic substrates. We have identified UBXN7, the cofactor protein of the CRL2VHL ligase complex, as a specific substrate of MUL1 ligase. CRL2VHL ligase complex regulates HIF-1α protein levels under aerobic (normoxia) or anaerobic (hypoxia) conditions. Inactivation of MUL1 ligase leads to accumulation of UBXN7, with concomitant increase in HIF-1α protein levels, reduction in oxidative phosphorylation, and increased glycolysis. We describe a novel pathway that originates in the mitochondria and operates upstream of the CRL2VHL ligase complex. Furthermore, we delineate the mechanism by which the mitochondria, through MUL1 ligase, can inhibit the CRL2VHL complex leading to high HIF-1α protein levels and a metabolic shift to glycolysis under normoxic conditions.
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Sui X, Li YM. Development of Ubiquitin Tools for Studies of Complex Ubiquitin Processing Protein Machines. CURR ORG CHEM 2020. [DOI: 10.2174/1385272823666191113161511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
:
Ubiquitination is one of the most extensive post-translational modifications in
eukaryotes and is involved in various physiological processes such as protein degradation,
autophagy, protein interaction, and protein localization. The ubiquitin (Ub)-related protein
machines include Ub-activating enzymes (E1s), Ub-conjugating enzymes (E2s), Ub ligases
(E3s), deubiquitinating enzymes (DUBs), p97, and the proteasomes. In recent years,
the role of DUBs has been extensively studied and relatively well understood. On the
other hand, the functional mechanisms of the other more complex ubiquitin-processing
protein machines (e.g., E3, p97, and proteasomes) are still to be sufficiently well explored
due to their intricate nature. One of the hurdles facing the studies of these complex protein
machines is the challenge of developing tailor-designed structurally defined model substrates,
which unfortunately cannot be directly obtained using recombinant technology. Consequently, the acquisition
and synthesis of the ubiquitin tool molecules are essential for the elucidation of the functions and
structures of the complex ubiquitin-processing protein machines. This paper aims to highlight recent studies on
these protein machines based on the synthetic ubiquitin tool molecules.
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Affiliation(s)
- Xin Sui
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China
| | - Yi-Ming Li
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China
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The AAA+ ATPase p97, a cellular multitool. Biochem J 2017; 474:2953-2976. [PMID: 28819009 PMCID: PMC5559722 DOI: 10.1042/bcj20160783] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/17/2017] [Accepted: 07/21/2017] [Indexed: 12/17/2022]
Abstract
The AAA+ (ATPases associated with diverse cellular activities) ATPase p97 is essential to a wide range of cellular functions, including endoplasmic reticulum-associated degradation, membrane fusion, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation and chromatin-associated processes, which are regulated by ubiquitination. p97 acts downstream from ubiquitin signaling events and utilizes the energy from ATP hydrolysis to extract its substrate proteins from cellular structures or multiprotein complexes. A multitude of p97 cofactors have evolved which are essential to p97 function. Ubiquitin-interacting domains and p97-binding domains combine to form bi-functional cofactors, whose complexes with p97 enable the enzyme to interact with a wide range of ubiquitinated substrates. A set of mutations in p97 have been shown to cause the multisystem proteinopathy inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia. In addition, p97 inhibition has been identified as a promising approach to provoke proteotoxic stress in tumors. In this review, we will describe the cellular processes governed by p97, how the cofactors interact with both p97 and its ubiquitinated substrates, p97 enzymology and the current status in developing p97 inhibitors for cancer therapy.
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Hänzelmann P, Schindelin H. The Interplay of Cofactor Interactions and Post-translational Modifications in the Regulation of the AAA+ ATPase p97. Front Mol Biosci 2017; 4:21. [PMID: 28451587 PMCID: PMC5389986 DOI: 10.3389/fmolb.2017.00021] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/24/2017] [Indexed: 12/18/2022] Open
Abstract
The hexameric type II AAA ATPase (ATPase associated with various activities) p97 (also referred to as VCP, Cdc48, and Ter94) is critically involved in a variety of cellular activities including pathways such as DNA replication and repair which both involve chromatin remodeling, and is a key player in various protein quality control pathways mediated by the ubiquitin proteasome system as well as autophagy. Correspondingly, p97 has been linked to various pathophysiological states including cancer, neurodegeneration, and premature aging. p97 encompasses an N-terminal domain, two highly conserved ATPase domains and an unstructured C-terminal tail. This enzyme hydrolyzes ATP and utilizes the resulting energy to extract or disassemble protein targets modified with ubiquitin from stable protein assemblies, chromatin and membranes. p97 participates in highly diverse cellular processes and hence its activity is tightly controlled. This is achieved by multiple regulatory cofactors, which either associate with the N-terminal domain or interact with the extreme C-terminus via distinct binding elements and target p97 to specific cellular pathways, sometimes requiring the simultaneous association with more than one cofactor. Most cofactors are recruited to p97 through conserved binding motifs/domains and assist in substrate recognition or processing by providing additional molecular properties. A tight control of p97 cofactor specificity and diversity as well as the assembly of higher-order p97-cofactor complexes is accomplished by various regulatory mechanisms, which include bipartite binding, binding site competition, changes in oligomeric assemblies, and nucleotide-induced conformational changes. Furthermore, post-translational modifications (PTMs) like acetylation, palmitoylation, phosphorylation, SUMOylation, and ubiquitylation of p97 have been reported which further modulate its diverse molecular activities. In this review, we will describe the molecular basis of p97-cofactor specificity/diversity and will discuss how PTMs can modulate p97-cofactor interactions and affect the physiological and patho-physiological functions of p97.
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Affiliation(s)
- Petra Hänzelmann
- Rudolf Virchow Center for Experimental Biomedicine, University of WürzburgWürzburg, Germany
| | - Hermann Schindelin
- Rudolf Virchow Center for Experimental Biomedicine, University of WürzburgWürzburg, Germany
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