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Qi A, Wang K, Li Y, Hu R, Hu G, Li Y, Shi G, Huang M. The degradation of α--synuclein is limited by dynein to drive the AALP pathway through HDAC6 upon paraquat exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 283:116841. [PMID: 39128448 DOI: 10.1016/j.ecoenv.2024.116841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 07/26/2024] [Accepted: 08/02/2024] [Indexed: 08/13/2024]
Abstract
Lewy body disease (LBD), one of the most common neurodegenerative diseases (NDDs), is characterized by excessive accumulation of α-synuclein (α-syn) in neurons. In recent years, environmental factors such as exposure to herbicides and pesticides have been attributed to the development of this condition. While majority of the studies on neurotoxic effects of paraquat (PQ) have focused on α-syn-mediated neuronal damage in the early stages of α-syn accumulation in neurons, efforts to explore the key target for α-syn degradation are limited. Recent research has suggested that histone deacetylase 6 (HDAC6) might possibly regulate amyloid clearance, and that the metabolism of compounds in neurons is also directly affected by axonal transport in neurons. Dynein predominantly mediates reverse transportation of metabolites and uptake of signal molecules and other compounds at the end of axons, which is conducive to the reuse of cell components. However, the role of interaction of dynein with HDAC6 in metabolites transport is still unclear. Therefore, this study aimed to investigate the role of HDAC6 in α-syn accumulation/clearance in neurons and the associated possible influencing factors. The results revealed that HDAC6 could transport ubiquitinated α-syn, bind to dynein, form an aggresome, and relocate to the center of the microtubule tissue, ultimately reducing abnormal accumulation of α-syn. However, PQ treatment resulted in HDAC6 upregulation, causing abnormal aggregation of α-syn. Taken together, these findings indicated that PQ exposure caused abnormal accumulation of α-syn and decreased effective degradation of α-syn by HDAC6-mediated aggresome-autophagy-lysosome pathway.
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Affiliation(s)
- Ai Qi
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China
| | - Kaidong Wang
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China
| | - Yujing Li
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China
| | - Rong Hu
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China
| | - Guiling Hu
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China
| | - Yang Li
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China
| | - Ge Shi
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China.
| | - Min Huang
- School of Public Health, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China; Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, No.1160, Shengli Street, Xingqing District, Yinchuan, Ningxia, China.
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2
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Visintin R, Ray SK. Intersections of Ubiquitin-Proteosome System and Autophagy in Promoting Growth of Glioblastoma Multiforme: Challenges and Opportunities. Cells 2022; 11:cells11244063. [PMID: 36552827 PMCID: PMC9776575 DOI: 10.3390/cells11244063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022] Open
Abstract
Glioblastoma multiforme (GBM) is a brain tumor notorious for its propensity to recur after the standard treatments of surgical resection, ionizing radiation (IR), and temozolomide (TMZ). Combined with the acquired resistance to standard treatments and recurrence, GBM is an especially deadly malignancy with hardly any worthwhile treatment options. The treatment resistance of GBM is influenced, in large part, by the contributions from two main degradative pathways in eukaryotic cells: ubiquitin-proteasome system (UPS) and autophagy. These two systems influence GBM cell survival by removing and recycling cellular components that have been damaged by treatments, as well as by modulating metabolism and selective degradation of components of cell survival or cell death pathways. There has recently been a large amount of interest in potential cancer therapies involving modulation of UPS or autophagy pathways. There is significant crosstalk between the two systems that pose therapeutic challenges, including utilization of ubiquitin signaling, the degradation of components of one system by the other, and compensatory activation of autophagy in the case of proteasome inhibition for GBM cell survival and proliferation. There are several important regulatory nodes which have functions affecting both systems. There are various molecular components at the intersections of UPS and autophagy pathways that pose challenges but also show some new therapeutic opportunities for GBM. This review article aims to provide an overview of the recent advancements in research regarding the intersections of UPS and autophagy with relevance to finding novel GBM treatment opportunities, especially for combating GBM treatment resistance.
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Affiliation(s)
- Rhett Visintin
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Swapan K. Ray
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC 29209, USA
- Correspondence: ; Tel.: +1-803-216-3420; Fax: +1-803-216-3428
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3
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Kaur S, Rajoria P, Chopra M. HDAC6: A unique HDAC family member as a cancer target. Cell Oncol (Dordr) 2022; 45:779-829. [PMID: 36036883 DOI: 10.1007/s13402-022-00704-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2022] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND HDAC6, a structurally and functionally distinct member of the HDAC family, is an integral part of multiple cellular functions such as cell proliferation, apoptosis, senescence, DNA damage and genomic stability, all of which when deregulated contribute to carcinogenesis. Among several HDAC family members known so far, HDAC6 holds a unique position. It differs from the other HDAC family members not only in terms of its subcellular localization, but also in terms of its substrate repertoire and hence cellular functions. Recent findings have considerably expanded the research related to the substrate pool, biological functions and regulation of HDAC6. Studies in HDAC6 knockout mice highlighted the importance of HDAC6 as a cell survival player in stressful situations, making it an important anticancer target. There is ample evidence stressing the importance of HDAC6 as an anti-cancer synergistic partner of many chemotherapeutic drugs. HDAC6 inhibitors have been found to enhance the effectiveness of conventional chemotherapeutic drugs such as DNA damaging agents, proteasome inhibitors and microtubule inhibitors, thereby highlighting the importance of combination therapies involving HDAC6 inhibitors and other anti-cancer agents. CONCLUSIONS Here, we present a review on HDAC6 with emphasis on its role as a critical regulator of specific physiological cellular pathways which when deregulated contribute to tumorigenesis, thereby highlighting the importance of HDAC6 inhibitors as important anticancer agents alone and in combination with other chemotherapeutic drugs. We also discuss the synergistic anticancer effect of combination therapies of HDAC6 inhibitors with conventional chemotherapeutic drugs.
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Affiliation(s)
- Sumeet Kaur
- Laboratory of Molecular Modeling and Anticancer Drug Development, Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, 110007, India
| | - Prerna Rajoria
- Laboratory of Molecular Modeling and Anticancer Drug Development, Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, 110007, India
| | - Madhu Chopra
- Laboratory of Molecular Modeling and Anticancer Drug Development, Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, 110007, India.
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4
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Maitland MER, Lajoie GA, Shaw GS, Schild-Poulter C. Structural and Functional Insights into GID/CTLH E3 Ligase Complexes. Int J Mol Sci 2022; 23:5863. [PMID: 35682545 PMCID: PMC9180843 DOI: 10.3390/ijms23115863] [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: 04/22/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 11/29/2022] Open
Abstract
Multi-subunit E3 ligases facilitate ubiquitin transfer by coordinating various substrate receptor subunits with a single catalytic center. Small molecules inducing targeted protein degradation have exploited such complexes, proving successful as therapeutics against previously undruggable targets. The C-terminal to LisH (CTLH) complex, also called the glucose-induced degradation deficient (GID) complex, is a multi-subunit E3 ligase complex highly conserved from Saccharomyces cerevisiae to humans, with roles in fundamental pathways controlling homeostasis and development in several species. However, we are only beginning to understand its mechanistic basis. Here, we review the literature of the CTLH complex from all organisms and place previous findings on individual subunits into context with recent breakthroughs on its structure and function.
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Affiliation(s)
- Matthew E. R. Maitland
- Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5B7, Canada;
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON N6G 2V4, Canada; (G.A.L.); (G.S.S.)
| | - Gilles A. Lajoie
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON N6G 2V4, Canada; (G.A.L.); (G.S.S.)
| | - Gary S. Shaw
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON N6G 2V4, Canada; (G.A.L.); (G.S.S.)
| | - Caroline Schild-Poulter
- Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5B7, Canada;
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON N6G 2V4, Canada; (G.A.L.); (G.S.S.)
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5
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Klickstein JA, Mukkavalli S, Raman M. AggreCount: an unbiased image analysis tool for identifying and quantifying cellular aggregates in a spatially defined manner. J Biol Chem 2021; 295:17672-17683. [PMID: 33454006 PMCID: PMC7762942 DOI: 10.1074/jbc.ra120.015398] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/13/2020] [Indexed: 01/17/2023] Open
Abstract
Protein quality control is maintained by a number of integrated cellular pathways that monitor the folding and functionality of the cellular proteome. Defects in these pathways lead to the accumulation of misfolded or faulty proteins that may become insoluble and aggregate over time. Protein aggregates significantly contribute to the development of a number of human diseases such as amyotrophic lateral sclerosis, Huntington's disease, and Alzheimer's disease. In vitro, imaging-based, cellular studies have defined key biomolecular components that recognize and clear aggregates; however, no unifying method is available to quantify cellular aggregates, limiting our ability to reproducibly and accurately quantify these structures. Here we describe an ImageJ macro called AggreCount to identify and measure protein aggregates in cells. AggreCount is designed to be intuitive, easy to use, and customizable for different types of aggregates observed in cells. Minimal experience in coding is required to utilize the script. Based on a user-defined image, AggreCount will report a number of metrics: (i) total number of cellular aggregates, (ii) percentage of cells with aggregates, (iii) aggregates per cell, (iv) area of aggregates, and (v) localization of aggregates (cytosol, perinuclear, or nuclear). A data table of aggregate information on a per cell basis, as well as a summary table, is provided for further data analysis. We demonstrate the versatility of AggreCount by analyzing a number of different cellular aggregates including aggresomes, stress granules, and inclusion bodies caused by huntingtin polyglutamine expansion.
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Affiliation(s)
- Jacob Aaron Klickstein
- Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Sirisha Mukkavalli
- Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Malavika Raman
- Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, USA.
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6
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Olasunkanmi OI, Chen S, Mageto J, Zhong Z. Virus-Induced Cytoplasmic Aggregates and Inclusions are Critical Cellular Regulatory and Antiviral Factors. Viruses 2020; 12:v12040399. [PMID: 32260341 PMCID: PMC7232513 DOI: 10.3390/v12040399] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/26/2020] [Accepted: 04/01/2020] [Indexed: 12/18/2022] Open
Abstract
RNA granules, aggresomes, and autophagy are key players in the immune response to viral infections. They provide countermeasures that regulate translation and proteostasis in order to rewire cell signaling, prevent viral interference, and maintain cellular homeostasis. The formation of cellular aggregates and inclusions is one of the strategies to minimize viral infections and virus-induced cell damage and to promote cellular survival. However, viruses have developed several strategies to interfere with these cellular processes in order to achieve productive replication within the host cells. A review on how these mechanisms could function as modulators of cell signaling and antiviral factors will be instrumental in refining the current scientific knowledge and proposing means whereby cellular granules and aggregates could be induced or prevented to enhance the antiviral immune response in mammalian cells.
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7
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HDAC6-an Emerging Target Against Chronic Myeloid Leukemia? Cancers (Basel) 2020; 12:cancers12020318. [PMID: 32013157 PMCID: PMC7072136 DOI: 10.3390/cancers12020318] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 02/06/2023] Open
Abstract
Imatinib became the standard treatment for chronic myeloid leukemia (CML) about 20 years ago, which was a major breakthrough in stabilizing the pathology and improving the quality of life of patients. However, the emergence of resistance to imatinib and other tyrosine kinase inhibitors leads researchers to characterize new therapeutic targets. Several studies have highlighted the role of histone deacetylase 6 (HDAC6) in various pathologies, including cancer. This protein effectively intervenes in cellular activities by its primarily cytoplasmic localization. In this review, we will discuss the molecular characteristics of the HDAC6 protein, as well as its overexpression in CML leukemic stem cells, which make it a promising therapeutic target for the treatment of CML.
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8
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Targeting Aggrephagy for the Treatment of Alzheimer's Disease. Cells 2020; 9:cells9020311. [PMID: 32012902 PMCID: PMC7072705 DOI: 10.3390/cells9020311] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/25/2020] [Accepted: 01/26/2020] [Indexed: 12/17/2022] Open
Abstract
Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases in older individuals with specific neuropsychiatric symptoms. It is a proteinopathy, pathologically characterized by the presence of misfolded protein (Aβ and Tau) aggregates in the brain, causing progressive dementia. Increasing studies have provided evidence that the defect in protein-degrading systems, especially the autophagy-lysosome pathway (ALP), plays an important role in the pathogenesis of AD. Recent studies have demonstrated that AD-associated protein aggregates can be selectively recognized by some receptors and then be degraded by ALP, a process termed aggrephagy. In this study, we reviewed the role of aggrephagy in AD development and discussed the strategy of promoting aggrephagy using small molecules for the treatment of AD.
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9
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Qin S, Jiang C, Gao J. Transcriptional factor Nrf2 is essential for aggresome formation during proteasome inhibition. Biomed Rep 2019; 11:241-252. [PMID: 31798869 PMCID: PMC6873428 DOI: 10.3892/br.2019.1247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022] Open
Abstract
Aggrephagy, the aggresome-related protein degradation system, represents a protective cellular response to shuttle misfolded proteins into the microtubule-organizing center for degradation through the autophagic pathway during stress conditions, including heat shock, oxidative stress and proteasome inhibition. In response to proteasome failure, many genes are transcriptionally activated to facilitate ubiquitinated proteins to be cleared via the aggrephagy pathway. Although many regulators involved in aggresome formation have been identified, the mechanism how transcriptional activation promotes aggresome formation remains unknown. Here, we have demonstrated that nuclear factor erythroid 2-related factor 2 (Nrf2) accumulated in the nucleus and activated the transcription of sequestosome-1 (p62) during proteasome inhibition in 293 cells. Loss of Nrf2 resulted in failure of aggresome formation and cell death; whereas overexpression of p62 alleviated Nrf2 knockdown-induced aggresome formation defects and promoted cell survival. Notably, blocking Nrf2 activation using a p38/MAPK inhibitor prevented proteasome inhibitor-induced aggresome formation. These findings suggested that Nrf2 may be a critical regulator of aggresome formation, which protects cells from proteasome dysfunction-induced stress.
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Affiliation(s)
- Siyue Qin
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, School of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China.,Key Laboratory of Obstetrics, Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610065, P.R. China
| | - Changan Jiang
- Key Laboratory of Obstetrics, Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610065, P.R. China
| | - Ju Gao
- Key Laboratory of Obstetrics, Gynecologic and Pediatric Diseases and Birth Defects, Ministry of Education, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610065, P.R. China.,The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, Fujian 350002, P.R. China
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10
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Yehia M, Taha H, Salama A, Amer N, Mosaab A, Hassanain O, Refaat A, Yassin D, El-Hemaly A, Ahmed S, El-Beltagy M, Shaalan O, El-Naggar S. Association of Aggresomes with Survival Outcomes in Pediatric Medulloblastoma. Sci Rep 2019; 9:12605. [PMID: 31471537 PMCID: PMC6717208 DOI: 10.1038/s41598-019-49027-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 08/14/2019] [Indexed: 12/22/2022] Open
Abstract
Aggresomes are inclusion bodies for misfolded/aggregated proteins. Despite the role of misfolded/aggregated proteins in neurological disorders, their role in cancer pathogenesis is poorly defined. In the current study we aimed to investigate whether aggresomes-positivity could be used to improve the disease subclassification and prognosis prediction of pediatric medulloblastoma. Ninety three pediatric medulloblastoma tumor samples were retrospectively stratified into three molecular subgroups; WNT, SHH and non-WNT/non-SHH, using immunohistochemistry and Multiplex Ligation Probe Amplification. Formation of aggresomes were detected using immunohistochemistry. Overall survival (OS) and event-free survival (EFS) were determined according to risk stratification criteria. Multivariate Cox regression analyses were carried out to exclude confounders. Aggresomes formation was detected in 63.4% (n = 59/93) of samples. Aggresomes were non-randomly distributed among different molecular subgroups (P = 0.00002). Multivariate Cox model identified aggresomes' percentage at ≥20% to be significantly correlated with patient outcome in both OS (HR = 3.419; 95% CI, 1.30-8.93; P = 0.01) and EFS (HR = 3; 95% CI, 1.19-7.53; P = 0.02). The presence of aggresomes in ≥20% of the tumor identified poor responders in standard risk patients; OS (P = 0.02) and EFS (P = 0.06), and significantly correlated with poor outcome in non-WNT/non-SHH molecular subgroup; OS (P = 0.0002) and EFS (P = 0.0004).
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Affiliation(s)
- Maha Yehia
- Department of Pathology, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Molecular Diagnostics, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Menoufia, Egypt
| | - Hala Taha
- Department of Pathology, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Asmaa Salama
- Department of Pathology, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Nada Amer
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
| | - Amal Mosaab
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
| | - Omneya Hassanain
- Clinical Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
| | - Amal Refaat
- Department of Radiology, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Radiology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Dina Yassin
- Laboratory of Molecular Biology, Department of Clinical Pathology, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Clinical Pathology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Ahmed El-Hemaly
- Department of Pediatric Oncology, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Pediatric Oncology, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Soha Ahmed
- Department of Radiotherapy, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Clinical Oncology, Faculty of Medicine, Aswan University, Aswan, Egypt
| | - Mohamed El-Beltagy
- Department of Neurosurgery, Children's Cancer Hospital Egypt 57357, Cairo, Egypt
- Department of Neurosurgery, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Osama Shaalan
- Department of Molecular Diagnostics, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Menoufia, Egypt
| | - Shahenda El-Naggar
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, Cairo, Egypt.
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11
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Liu H, Pfirrmann T. The Gid-complex: an emerging player in the ubiquitin ligase league. Biol Chem 2019; 400:1429-1441. [DOI: 10.1515/hsz-2019-0139] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 02/20/2019] [Indexed: 12/16/2022]
Abstract
Abstract
The Saccharomyces cerevisiae Gid-complex is a highly evolutionary conserved ubiquitin ligase with at least seven protein subunits. Here, we review our knowledge about the yeast Gid-complex as an important regulator of glucose metabolism, specifically targeting key enzymes of gluconeogenesis for degradation. Furthermore, we summarize existing data about the individual subunits, the topology and possible substrate recognition mechanisms and compare the striking similarities, but also differences, between the yeast complex and its vertebrate counterpart. Present data is summarized to give an overview about cellular processes regulated by the vertebrate GID-complex that range from cell cycle regulation, primary cilia function to the regulation of energy homeostasis. In conclusion, the vertebrate GID-complex evolved as a versatile ubiquitin ligase complex with functions beyond the regulation of glucose metabolism.
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Affiliation(s)
- Huaize Liu
- Martin Luther University Halle-Wittenberg , Institute of Physiological Chemistry , Hollystr. 1 , D-06114 Halle , Germany
| | - Thorsten Pfirrmann
- Martin Luther University Halle-Wittenberg , Institute of Physiological Chemistry , Hollystr. 1 , D-06114 Halle , Germany
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12
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Nagata S, Marunouchi T, Tanonaka K. Histone Deacetylase Inhibitor SAHA Treatment Prevents the Development of Heart Failure after Myocardial Infarction via an Induction of Heat-Shock Proteins in Rats. Biol Pharm Bull 2019; 42:453-461. [DOI: 10.1248/bpb.b18-00785] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Shiho Nagata
- Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy and Life Sciences
| | - Tetsuro Marunouchi
- Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy and Life Sciences
| | - Kouichi Tanonaka
- Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy and Life Sciences
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13
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Regulation of c-Raf Stability through the CTLH Complex. Int J Mol Sci 2019; 20:ijms20040934. [PMID: 30795516 PMCID: PMC6412545 DOI: 10.3390/ijms20040934] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 02/14/2019] [Indexed: 12/23/2022] Open
Abstract
c-Raf is a central component of the extracellular signal-regulated kinase (ERK) pathway which is implicated in the development of many cancer types. RanBPM (Ran-Binding Protein M) was previously shown to inhibit c-Raf expression, but how this is achieved remains unclear. RanBPM is part of a recently identified E3 ubiquitin ligase complex, the CTLH (C-terminal to LisH) complex. Here, we show that the CTLH complex regulates c-Raf expression through a control of its degradation. Several domains of RanBPM were found necessary to regulate c-Raf levels, but only the C-terminal CRA (CT11-RanBPM) domain showed direct interaction with c-Raf. c-Raf ubiquitination and degradation is promoted by the CTLH complex. Furthermore, A-Raf and B-Raf protein levels are also regulated by the CTLH complex, indicating a common regulation of Raf family members. Finally, depletion of CTLH subunits RMND5A (required for meiotic nuclear division 5A) and RanBPM resulted in enhanced proliferation and loss of RanBPM promoted tumour growth in a mouse model. This study uncovers a new mode of control of c-Raf expression through regulation of its degradation by the CTLH complex. These findings also uncover a novel target of the CTLH complex, and suggest that the CTLH complex has activities that suppress cell transformation and tumour formation.
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14
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Ogrodnik M, Salmonowicz H, Gladyshev VN. Integrating cellular senescence with the concept of damage accumulation in aging: Relevance for clearance of senescent cells. Aging Cell 2019; 18:e12841. [PMID: 30346102 PMCID: PMC6351832 DOI: 10.1111/acel.12841] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 07/31/2018] [Accepted: 08/20/2018] [Indexed: 12/12/2022] Open
Abstract
Understanding the aging process and ways to manipulate it is of major importance for biology and medicine. Among the many aging theories advanced over the years, the concept most consistent with experimental evidence posits the buildup of numerous forms of molecular damage as a foundation of the aging process. Here, we discuss that this concept integrates well with recent findings on cellular senescence, offering a novel view on the role of senescence in aging and age‐related disease. Cellular senescence has a well‐established role in cellular aging, but its impact on the rate of organismal aging is less defined. One of the most prominent features of cellular senescence is its association with macromolecular damage. The relationship between cell senescence and damage concerns both damage as a molecular signal of senescence induction and accelerated accumulation of damage in senescent cells. We describe the origin, regulatory mechanisms, and relevance of various damage forms in senescent cells. This view on senescent cells as carriers and inducers of damage puts new light on senescence, considering it as a significant contributor to the rise in organismal damage. Applying these ideas, we critically examine current evidence for a role of cellular senescence in aging and age‐related diseases. We also discuss the differential impact of longevity interventions on senescence burden and other types of age‐related damage. Finally, we propose a model on the role of aging‐related damage accumulation and the rate of aging observed upon senescent cell clearance.
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Affiliation(s)
- Mikolaj Ogrodnik
- Institute for Cell and Molecular Biosciences; Newcastle University Institute for Ageing; Newcastle upon Tyne UK
| | - Hanna Salmonowicz
- Institute for Cell and Molecular Biosciences; Newcastle University Institute for Ageing; Newcastle upon Tyne UK
| | - Vadim N. Gladyshev
- Division of Genetics; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston Massachusetts
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15
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Salemi LM, Maitland MER, McTavish CJ, Schild-Poulter C. Cell signalling pathway regulation by RanBPM: molecular insights and disease implications. Open Biol 2018; 7:rsob.170081. [PMID: 28659384 PMCID: PMC5493780 DOI: 10.1098/rsob.170081] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 06/01/2017] [Indexed: 12/25/2022] Open
Abstract
RanBPM (Ran-binding protein M, also called RanBP9) is an evolutionarily conserved, ubiquitous protein which localizes to both nucleus and cytoplasm. RanBPM has been implicated in the regulation of a number of signalling pathways to regulate several cellular processes such as apoptosis, cell adhesion, migration as well as transcription, and plays a critical role during development. In addition, RanBPM has been shown to regulate pathways implicated in cancer and Alzheimer's disease, implying that RanBPM has important functions in both normal and pathological development. While its functions in these processes are still poorly understood, RanBPM has been identified as a component of a large complex, termed the CTLH (C-terminal to LisH) complex. The yeast homologue of this complex functions as an E3 ubiquitin ligase that targets enzymes of the gluconeogenesis pathway. While the CTLH complex E3 ubiquitin ligase activity and substrates still remain to be characterized, the high level of conservation between the complexes in yeast and mammals infers that the CTLH complex could also serve to promote the degradation of specific substrates through ubiquitination, therefore suggesting the possibility that RanBPM's various functions may be mediated through the activity of the CTLH complex.
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Affiliation(s)
- Louisa M Salemi
- Robarts Research Institute, Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7
| | - Matthew E R Maitland
- Robarts Research Institute, Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7
| | - Christina J McTavish
- Robarts Research Institute, Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7
| | - Caroline Schild-Poulter
- Robarts Research Institute, Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, Ontario, Canada N6A 5B7
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16
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Phadwal K, Kurian D, Salamat MKF, MacRae VE, Diack AB, Manson JC. Spermine increases acetylation of tubulins and facilitates autophagic degradation of prion aggregates. Sci Rep 2018; 8:10004. [PMID: 29968775 PMCID: PMC6030104 DOI: 10.1038/s41598-018-28296-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/18/2018] [Indexed: 12/30/2022] Open
Abstract
Autolysosomal dysfunction and unstable microtubules are hallmarks of chronic neurodegenerative diseases associated with misfolded proteins. Investigation of impaired protein quality control and clearance systems could therefore provide an important avenue for intervention. To investigate this we have used a highly controlled model for protein aggregation, an in vitro prion system. Here we report that prion aggregates traffic via autolysosomes in the cytoplasm. Treatment with the natural polyamine spermine clears aggregates by enhancing autolysosomal flux. We demonstrated this by blocking the formation of mature autophagosomes resulting in accumulation of prion aggregates in the cytoplasm. Further we investigated the mechanism of spermine’s mode of action and we demonstrate that spermine increases the acetylation of microtubules, which is known to facilitate retrograde transport of autophagosomes from the cellular periphery to lysosomes located near the nucleus. We further report that spermine facilitates selective autophagic degradation of prion aggregates by binding to microtubule protein Tubb6. This is the first report in which spermine and the pathways regulated by it are applied as a novel approach towards clearance of misfolded prion protein and we suggest that this may have important implication for the broader family of protein misfolding diseases.
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Affiliation(s)
- Kanchan Phadwal
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Dominic Kurian
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | | | - Vicky E MacRae
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Abigail B Diack
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK
| | - Jean C Manson
- The Roslin Institute & R(D)SVS, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK. .,Centre for Dementia Prevention, University of Edinburgh, Edinburgh, UK. .,Edinburgh Neuroscience, University of Edinburgh, Edinburgh, UK.
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17
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Campbell S, Suwan K, Waramit S, Aboagye EO, Hajitou A. Selective Inhibition of Histone Deacetylation in Melanoma Increases Targeted Gene Delivery by a Bacteriophage Viral Vector. Cancers (Basel) 2018; 10:E125. [PMID: 29690504 PMCID: PMC5923380 DOI: 10.3390/cancers10040125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 04/16/2018] [Accepted: 04/19/2018] [Indexed: 01/14/2023] Open
Abstract
The previously developed adeno-associated virus/phage (AAVP) vector, a hybrid between M13 bacteriophage (phage) viruses that infect bacteria only and human Adeno-Associated Virus (AAV), is a promising tool in targeted gene therapy against cancer. AAVP can be administered systemically and made tissue specific through the use of ligand-directed targeting. Cancer cells and tumor-associated blood vessels overexpress the αν integrin receptors, which are involved in tumor angiogenesis and tumor invasion. AAVP is targeted to these integrins via a double cyclic RGD4C ligand displayed on the phage capsid. Nevertheless, there remain significant host-defense hurdles to the use of AAVP in targeted gene delivery and subsequently in gene therapy. We previously reported that histone deacetylation in cancer constitutes a barrier to AAVP. Herein, to improve AAVP-mediated gene delivery to cancer cells, we combined the vector with selective adjuvant chemicals that inhibit specific histone deacetylases (HDAC). We examined the effects of the HDAC inhibitor C1A that mainly targets HDAC6 and compared this to sodium butyrate, a pan-HDAC inhibitor with broad spectrum HDAC inhibition. We tested the effects on melanoma, known for HDAC6 up-regulation, and compared this side by side with a normal human kidney HEK293 cell line. Varying concentrations were tested to determine cytotoxic levels as well as effects on AAVP gene delivery. We report that the HDAC inhibitor C1A increased AAVP-mediated transgene expression by up to ~9-fold. These findings indicate that selective HDAC inhibition is a promising adjuvant treatment for increasing the therapeutic value of AAVP.
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Affiliation(s)
- Samuel Campbell
- Cancer Phage Therapy Laboratory, Division of Brain Sciences, Burlington Danes Building, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK.
| | - Keittisak Suwan
- Cancer Phage Therapy Laboratory, Division of Brain Sciences, Burlington Danes Building, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK.
| | - Sajee Waramit
- Cancer Phage Therapy Laboratory, Division of Brain Sciences, Burlington Danes Building, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK.
| | - Eric Ofori Aboagye
- Comprehensive Cancer Imaging Centre, Faculty of Medicine, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK.
| | - Amin Hajitou
- Cancer Phage Therapy Laboratory, Division of Brain Sciences, Burlington Danes Building, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK.
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18
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Tang WH, Zhuang XJ, Song SD, Wu H, Zhang Z, Yang YZ, Zhang HL, Mao JM, Liu DF, Zhao LM, Lin HC, Hong K, Ma LL, Qiao J, Qin W, Tang Y, Jiang H. Ran-binding protein M is associated with human spermatogenesis and oogenesis. Mol Med Rep 2017; 17:2257-2262. [PMID: 29207172 PMCID: PMC5783472 DOI: 10.3892/mmr.2017.8147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 10/06/2017] [Indexed: 12/02/2022] Open
Abstract
The aim of the present study was to explore the underlying mechanism and diagnostic potential of Ran-binding protein M (RanBPM) in human spermatogenesis and oogenesis. RanBPM expression in human testis and ovaries was analysed using polymerase chain reaction (PCR) and western blotting, and immunofluorescence was performed on testis and ovary tissue sections during different developmental stages of spermatogenesis and oogenesis using RanBPM antibodies. Interactions with a variety of functional proteins were also investigated. RanBPM mRNA and protein expression levels were determined by PCR and western blotting in the tissue sections. Results revealed that the mRNA expression levels were highest in the testis followed by the ovary. The RanBPM protein was predominantly localized in the nucleus of germ cells, and the expression levels were highest in pachytene spermatocytes and cells surrounding spermatids in testis tissue. In ovary cells, RanBPM was localized in the nucleus and cytoplasm. In conclusion, the results suggested that RanBPM may have multiple roles in the regulation of germ cell proliferation during human spermatogenesis and oogenesis. This research may provide a novel insight into the underlying molecular mechanism of RanBPM and may have implications for the clinical diagnosis and treatment of human infertility.
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Affiliation(s)
- Wen-Hao Tang
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Xin-Jie Zhuang
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Key Laboratory of Assisted Reproduction, Ministry of Education, Peking University Third Hospital, Beijing 100191, P.R. China
| | - Shi-De Song
- Department of Urology, Rizhao People's Hospital, Rizhao, Shandong 276500, P.R. China
| | - Han Wu
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Zhe Zhang
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Yu-Zhuo Yang
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Key Laboratory of Assisted Reproduction, Ministry of Education, Peking University Third Hospital, Beijing 100191, P.R. China
| | - Hong-Liang Zhang
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Key Laboratory of Assisted Reproduction, Ministry of Education, Peking University Third Hospital, Beijing 100191, P.R. China
| | - Jia-Ming Mao
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Key Laboratory of Assisted Reproduction, Ministry of Education, Peking University Third Hospital, Beijing 100191, P.R. China
| | - De-Feng Liu
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Key Laboratory of Assisted Reproduction, Ministry of Education, Peking University Third Hospital, Beijing 100191, P.R. China
| | - Lian-Ming Zhao
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Hao-Cheng Lin
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Kai Hong
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Lu-Lin Ma
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
| | - Jie Qiao
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Key Laboratory of Assisted Reproduction, Ministry of Education, Peking University Third Hospital, Beijing 100191, P.R. China
| | - Weibing Qin
- Key Laboratory of Male Reproduction and Genetics, National Health and Family Planning Commission, Family Planning Research Institute of Guangdong Province, Guangzhou, Guangdong 510600, P.R. China
| | - Yunge Tang
- Key Laboratory of Male Reproduction and Genetics, National Health and Family Planning Commission, Family Planning Research Institute of Guangdong Province, Guangzhou, Guangdong 510600, P.R. China
| | - Hui Jiang
- 1Department of Urology, The Third Hospital of Peking University, Beijing 100191, P.R. China
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19
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Nassar M, Samaha H, Ghabriel M, Yehia M, Taha H, Salem S, Shaaban K, Omar M, Ahmed N, El-Naggar S. LC3A Silencing Hinders Aggresome Vimentin Cage Clearance in Primary Choroid Plexus Carcinoma. Sci Rep 2017; 7:8022. [PMID: 28808307 PMCID: PMC5556083 DOI: 10.1038/s41598-017-07403-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/23/2017] [Indexed: 12/12/2022] Open
Abstract
Aggresomes are transient microtubule-dependent inclusion bodies that sequester misfolded proteins and are ultimately removed by autophagy. Here we report the generation of a choroid plexus carcinoma cell line; Children’s Cancer Hospital Egypt (CCHE)-45, which is characterized by the constitutive formation of aggresomes. When examining the autophagy pathway as the main route for aggresomes clearance, CCHE-45 cells displayed increased autophagy flux mediated by MAP1LC3B. MAP1LC3A-Variant1 gene expression was silenced by promoter methylation. Restoring MAP1LC3A-Variant1 expression resulted in the formation of MAP1LC3A positive autophagosmes and the disruption of the aggresomes' vimentin cage independent of MAP1LC3B positive autophagosomes. Our data supports the notion that basal quality control autophagy and vimentin cage clearance in CCHE-45 are mediated by MAP1LC3A. Hence we propose that absence of MAP1LC3A disrupts the autophagic pathway and leads to the failure of aggresome vimentin cage degradation. Consequently, this could represent a targetable pathway in autophagy-dependent cancers.
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Affiliation(s)
- Marwa Nassar
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt.,Biotechnology Graduate Program, American University in Cairo. New Cairo Campus, AUC Avenue, P.O Box 74, New Cairo, 11835, Egypt
| | - Heba Samaha
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt
| | - Myret Ghabriel
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt
| | - Maha Yehia
- Department of Pathology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt
| | - Hala Taha
- Department of Pathology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt.,National Cancer Institute (NCI), Cairo, Egypt
| | - Sherin Salem
- Department of Clinical Pathology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt.,National Cancer Institute (NCI), Cairo, Egypt
| | - Khaled Shaaban
- Department of Clinical Pathology, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt.,National Cancer Institute (NCI), Cairo, Egypt
| | - Mariam Omar
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt
| | - Nabil Ahmed
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt.,Center for Cell and Gene Therapy, Texas Children's Hospital, Baylor College of Medicine, 1102 Bates St. Suite 1700, Houston, Texas, 77030, USA
| | - Shahenda El-Naggar
- Tumor Biology Research Program, Basic Research Unit, Department of Research, Children's Cancer Hospital Egypt 57357, P.O Box 11441, 1 Seket Al-Emam Street, Cairo, Egypt.
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20
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Salemi LM, Maitland MER, Yefet ER, Schild-Poulter C. Inhibition of HDAC6 activity through interaction with RanBPM and its associated CTLH complex. BMC Cancer 2017; 17:460. [PMID: 28668087 PMCID: PMC5494137 DOI: 10.1186/s12885-017-3430-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/13/2017] [Indexed: 12/13/2022] Open
Abstract
Background Histone deacetylase 6 (HDAC6) is a microtubule-associated deacetylase that promotes many cellular processes that lead to cell transformation and tumour development. We previously documented an interaction between Ran-Binding Protein M (RanBPM) and HDAC6 and found that RanBPM expression inhibits HDAC6 activity. RanBPM is part of a putative E3 ubiquitin ligase complex, termed the C-terminal to LisH (CTLH) complex. Here, we investigated the involvement of the CTLH complex on HDAC6 inhibition and assessed the outcome of this regulation on the cellular motility induced by HDAC6. Methods Cell lines (Hela, HEK293 and immortalized mouse embryonic fibroblasts) stably or transiently downregulated for several components of the CTLH complex were employed for the assays used in this study. Interactions of HDAC6, RanBPM and muskelin were assessed by co-immunoprecipitations. Quantifications of western blot analyses were employed to evaluate acetylated α-tubulin levels. Confocal microscopy analyses were used to determine microtubule association of HDAC6 and CTLH complex members. Cell migration was evaluated using wound healing assays. Results We demonstrate that RanBPM-mediated inhibition of HDAC6 is dependent on its association with HDAC6. We show that, while HDAC6 does not require RanBPM to associate with microtubules, RanBPM association with microtubules requires HDAC6. Additionally, we show that Twa1 (Two-hybrid-associated protein 1 with RanBPM) and MAEA (Macrophage Erythroblast Attacher), two CTLH complex members, also associate with α-tubulin and that muskelin, another component of the CTLH complex, is able to associate with HDAC6. Downregulation of CTLH complex members muskelin and Rmnd5A (Required for meiotic nuclear division homolog A) resulted in decreased acetylation of HDAC6 substrate α-tubulin. Finally, we demonstrate that the increased cell migration resulting from downregulation of RanBPM is due to the relief in inhibition of HDAC6 α-tubulin deacetylase activity. Conclusions Our work shows that RanBPM, together with the CTLH complex, associates with HDAC6 and restricts cell migration through inhibition of HDAC6 activity. This study uncovers a novel function for the CTLH complex and suggests that it could have a tumour suppressive role in restricting HDAC6 oncogenic properties. Electronic supplementary material The online version of this article (doi:10.1186/s12885-017-3430-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Louisa M Salemi
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada
| | - Matthew E R Maitland
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada
| | - Eyal R Yefet
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada
| | - Caroline Schild-Poulter
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, 1151 Richmond Street North, London, ON, N6A 5B7, Canada.
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21
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Zheng K, Jiang Y, He Z, Kitazato K, Wang Y. Cellular defence or viral assist: the dilemma of HDAC6. J Gen Virol 2017; 98:322-337. [PMID: 27959772 DOI: 10.1099/jgv.0.000679] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Histone deacetylase 6 (HDAC6) is a unique cytoplasmic deacetylase that regulates various important biological processes by preventing protein aggregation and deacetylating different non-histone substrates including tubulin, heat shock protein 90, cortactin, retinoic acid inducible gene I and β-catenin. Growing evidence has indicated a dual role for HDAC6 in viral infection and pathogenesis: HDAC6 may represent a host defence mechanism against viral infection by modulating microtubule acetylation, triggering antiviral immune response and stimulating protective autophagy, or it may be hijacked by the virus to enhance proinflammatory response. In this review, we will highlight current data illustrating the complexity and importance of HDAC6 in viral pathogenesis. We will summarize the structure and functional specificity of HDAC6, and its deacetylase- and ubiquitin-dependent activity in key cellular events in response to virus infection. We will also discuss how HDAC6 exerts its direct or indirect histone modification ability in viral lytic-latency switch.
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Affiliation(s)
- Kai Zheng
- Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen 518060, PR China.,College of Life Science and Technology, Guangzhou Jinan Biomedicine Research and Development Center, Jinan University, Guangzhou 510632, PR China
| | - Yingchun Jiang
- Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen 518060, PR China
| | - Zhendan He
- Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen 518060, PR China
| | - Kaio Kitazato
- Division of Molecular Pharmacology of Infectious Agents, Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
| | - Yifei Wang
- College of Life Science and Technology, Guangzhou Jinan Biomedicine Research and Development Center, Jinan University, Guangzhou 510632, PR China
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22
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Li ZY, Zhang C, Zhang Y, Chen L, Chen BD, Li QZ, Zhang XJ, Li WP. A novel HDAC6 inhibitor Tubastatin A: Controls HDAC6-p97/VCP-mediated ubiquitination-autophagy turnover and reverses Temozolomide-induced ER stress-tolerance in GBM cells. Cancer Lett 2017; 391:89-99. [PMID: 28131906 DOI: 10.1016/j.canlet.2017.01.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 01/21/2023]
Abstract
Temozolomide (TMZ) is the cornerstone of therapy for glioblastoma multiforme (GBM). However, its efficacy is limited due to the development of multidrug resistance (MDR). In this study, we first identified the occurrence of ER stress-tolerance (ERST) in glioma cells and confirmed that ERST was positively correlated with TMZ resistance. We further showed that the seesaw-effect of HDAC6-p97/VCP (increased HDAC6 and decreased p97/VCP) in glioma cells was crucial to ERST-associated TMZ resistance. Moreover, the combination treatment of Tubastatin A (TUB, a selective inhibitor of HDAC6) and TMZ synergistically overcame ERST, reduced cell viability and induced apoptosis in TMZ-resistant glioma cells. TUB and TMZ triggered pro-apoptotic signals of the unfolded protein response (UPR) and ER stress and reversed the ratio between HDAC6 and p97/VCP, which potentially attenuated the activation of heat shock proteins and mediated the reversal of ERST. The combination treatment also triggered the dissociation of Dynein-HDAC6 and attenuation of the Dynein-Dynactin motor complex. In addition, this treatment induced HDAC6-p97/VCP-mediated ubiquitination-autophagy turnover, which was involved in the degradation and clearance of ubiquitinated misfolded proteins. This effect could be partially reversed by HDAC6 KO and/or p97/VCP overexpression. Therefore, we proposed that glioma cells optimized the clearance of ubiquitinated misfolded proteins via the reinforcement of HDAC6-facilitated autophagy and attenuation of the p97/VCP-mediated ubiquitin-proteasome system (UPS). In conclusion, our findings showed that the balance of HDAC6-p97/VCP was crucial to ERST-associated TMZ resistance and that HDAC6 inhibition might be a synergistic target and strategy along with TMZ for the improvement of clinical glioma treatment.
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Affiliation(s)
- Zong-Yang Li
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Ce Zhang
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Yuan Zhang
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Lei Chen
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Bao-Dong Chen
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Qing-Zhong Li
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Xie-Jun Zhang
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China
| | - Wei-Ping Li
- Shenzhen Key Laboratory of Neurosurgery, Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002# Sungang Road, Futian District, Shenzhen 518035, China.
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23
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Génier S, Degrandmaison J, Moreau P, Labrecque P, Hébert TE, Parent JL. Regulation of GPCR expression through an interaction with CCT7, a subunit of the CCT/TRiC complex. Mol Biol Cell 2016; 27:3800-3812. [PMID: 27708139 PMCID: PMC5170604 DOI: 10.1091/mbc.e16-04-0224] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 09/22/2016] [Accepted: 09/26/2016] [Indexed: 12/25/2022] Open
Abstract
A direct and functional interaction between a subunit of the CCT/TCP-1 ring complex (TRiC) chaperonin complex and G protein–coupled receptor (GPCRs) is shown. Evidence is provided that distinct nascent GPCRs can undergo alternative folding pathways and that CCT/TRiC is critical in preventing aggregation of some GPCRs and in promoting their proper maturation and expression. Mechanisms that prevent aggregation and promote folding of nascent G protein–coupled receptors (GPCRs) remain poorly understood. We identified chaperonin containing TCP-1 subunit eta (CCT7) as an interacting partner of the β-isoform of thromboxane A2 receptor (TPβ) by yeast two-hybrid screening. CCT7 coimmunoprecipitated with overexpressed TPβ and β2-adrenergic receptor (β2AR) in HEK 293 cells, but also with endogenous β2AR. CCT7 depletion by small interfering RNA reduced total and cell-surface expression of both receptors and caused redistribution of the receptors to juxtanuclear aggresomes, significantly more so for TPβ than β2AR. Interestingly, Hsp90 coimmunoprecipitated with β2AR but virtually not with TPβ, indicating that nascent GPCRs can adopt alternative folding pathways. In vitro pull-down assays showed that both receptors can interact directly with CCT7 through their third intracellular loops and C-termini. We demonstrate that Trp334 in the TPβ C-terminus is critical for the CCT7 interaction and plays an important role in TPβ maturation and cell-surface expression. Of note, introducing a tryptophan in the corresponding position of the TPα isoform confers the CCT7-binding and maturation properties of TPβ. We show that an interaction with a subunit of the CCT/TCP-1 ring complex (TRiC) chaperonin complex is involved in regulating aggregation of nascent GPCRs and in promoting their proper maturation and expression.
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Affiliation(s)
- Samuel Génier
- Service de Rhumatologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke (CR-CHUS), and Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Jade Degrandmaison
- Service de Rhumatologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke (CR-CHUS), and Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Pierrick Moreau
- Service de Rhumatologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke (CR-CHUS), and Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Pascale Labrecque
- Service de Rhumatologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke (CR-CHUS), and Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3G 1Y6, Canada
| | - Jean-Luc Parent
- Service de Rhumatologie, Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke (CR-CHUS), and Institut de Pharmacologie de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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Palmieri D, Scarpa M, Tessari A, Uka R, Amari F, Lee C, Richmond T, Foray C, Sheetz T, Braddom A, Burd CE, Parvin JD, Ludwig T, Croce CM, Coppola V. Ran Binding Protein 9 (RanBP9) is a novel mediator of cellular DNA damage response in lung cancer cells. Oncotarget 2016; 7:18371-83. [PMID: 26943034 PMCID: PMC4951294 DOI: 10.18632/oncotarget.7813] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/29/2016] [Indexed: 01/27/2023] Open
Abstract
Ran Binding Protein 9 (RanBP9, also known as RanBPM) is an evolutionary conserved scaffold protein present both in the nucleus and the cytoplasm of cells whose biological functions remain elusive. We show that active ATM phosphorylates RanBP9 on at least two different residues (S181 and S603). In response to IR, RanBP9 rapidly accumulates into the nucleus of lung cancer cells, but this nuclear accumulation is prevented by ATM inhibition. RanBP9 stable silencing in three different lung cancer cell lines significantly affects the DNA Damage Response (DDR), resulting in delayed activation of key components of the cellular response to IR such as ATM itself, Chk2, γH2AX, and p53. Accordingly, abrogation of RanBP9 expression reduces homologous recombination-dependent DNA repair efficiency, causing an abnormal activation of IR-induced senescence and apoptosis. In summary, here we report that RanBP9 is a novel mediator of the cellular DDR, whose accumulation into the nucleus upon IR is dependent on ATM kinase activity. RanBP9 absence hampers the molecular mechanisms leading to efficient repair of damaged DNA, resulting in enhanced sensitivity to genotoxic stress. These findings suggest that targeting RanBP9 might enhance lung cancer cell sensitivity to genotoxic anti-neoplastic treatment.
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Affiliation(s)
- Dario Palmieri
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Mario Scarpa
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Anna Tessari
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
| | - Rexhep Uka
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Foued Amari
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Cindy Lee
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Timothy Richmond
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
| | - Claudia Foray
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Tyler Sheetz
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
| | - Ashley Braddom
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
| | - Christin E. Burd
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Jeffrey D. Parvin
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Thomas Ludwig
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
| | - Carlo M. Croce
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
| | - Vincenzo Coppola
- Department of Molecular Virology, Immunology and Medical Genetics, College of Medicine, 43210 Columbus, OH, USA
- Solid Tumor Biology Program, Comprehensive Cancer Center, The Ohio State University, 43210 Columbus, OH, USA
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Controlled and Impaired Mitochondrial Quality in Neurons: Molecular Physiology and Prospective Pharmacology. Pharmacol Res 2015; 99:410-24. [DOI: 10.1016/j.phrs.2015.03.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 03/27/2015] [Accepted: 03/27/2015] [Indexed: 01/08/2023]
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Terzo EA, Lyons SM, Poulton JS, Temple BRS, Marzluff WF, Duronio RJ. Distinct self-interaction domains promote Multi Sex Combs accumulation in and formation of the Drosophila histone locus body. Mol Biol Cell 2015; 26:1559-74. [PMID: 25694448 PMCID: PMC4395134 DOI: 10.1091/mbc.e14-10-1445] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/12/2015] [Indexed: 11/11/2022] Open
Abstract
The Drosophila Multi Sex Combs (Mxc) protein is necessary for the recruitment of histone mRNA biosynthetic factors to the histone locus body (HLB). Mxc contains multiple domains required for HLB assembly and histone mRNA biosynthesis. Two N-terminal domains of Mxc are essential for promoting HLB assembly via a self-interaction. Nuclear bodies (NBs) are structures that concentrate proteins, RNAs, and ribonucleoproteins that perform functions essential to gene expression. How NBs assemble is not well understood. We studied the Drosophila histone locus body (HLB), a NB that concentrates factors required for histone mRNA biosynthesis at the replication-dependent histone gene locus. We coupled biochemical analysis with confocal imaging of both fixed and live tissues to demonstrate that the Drosophila Multi Sex Combs (Mxc) protein contains multiple domains necessary for HLB assembly. An important feature of this assembly process is the self-interaction of Mxc via two conserved N-terminal domains: a LisH domain and a novel self-interaction facilitator (SIF) domain immediately downstream of the LisH domain. Molecular modeling suggests that the LisH and SIF domains directly interact, and mutation of either the LisH or the SIF domain severely impairs Mxc function in vivo, resulting in reduced histone mRNA accumulation. A region of Mxc between amino acids 721 and 1481 is also necessary for HLB assembly independent of the LisH and SIF domains. Finally, the C-terminal 195 amino acids of Mxc are required for recruiting FLASH, an essential histone mRNA-processing factor, to the HLB. We conclude that multiple domains of the Mxc protein promote HLB assembly in order to concentrate factors required for histone mRNA biosynthesis.
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Affiliation(s)
- Esteban A Terzo
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599
| | - Shawn M Lyons
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599
| | - John S Poulton
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599
| | - Brenda R S Temple
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - William F Marzluff
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599 Department of Biology, University of North Carolina, Chapel Hill, NC 27599 Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599 Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599 Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599 Department of Biology, University of North Carolina, Chapel Hill, NC 27599 Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599 Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599 Department of Genetics, University of North Carolina, Chapel Hill, NC 27599
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Salemi LM, Loureiro SO, Schild-Poulter C. Characterization of RanBPM molecular determinants that control its subcellular localization. PLoS One 2015; 10:e0117655. [PMID: 25659156 PMCID: PMC4319831 DOI: 10.1371/journal.pone.0117655] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 12/30/2014] [Indexed: 12/14/2022] Open
Abstract
RanBPM/RanBP9 is a ubiquitous, nucleocytoplasmic protein that is part of an evolutionary conserved E3 ubiquitin ligase complex whose function and targets in mammals are still unknown. RanBPM itself has been implicated in various cellular processes that involve both nuclear and cytoplasmic functions. However, to date, little is known about how RanBPM subcellular localization is regulated. We have conducted a systematic analysis of RanBPM regions that control its subcellular localization using RanBPM shRNA cells to examine ectopic RanBPM mutant subcellular localization without interference from the endogenously expressed protein. We show that several domains and motifs regulate RanBPM nuclear and cytoplasmic localization. In particular, RanBPM comprises two motifs that can confer nuclear localization, one proline/glutamine-rich motif in the extreme N-terminus which has a dominant effect on RanBPM localization, and a second motif in the C-terminus which minimally contributes to RanBPM nuclear targeting. We also identified a nuclear export signal (NES) which mutation prevented RanBPM accumulation in the cytoplasm. Likewise, deletion of the central RanBPM conserved domains (SPRY and LisH/CTLH) resulted in the relocalization of RanBPM to the nucleus, suggesting that RanBPM cytoplasmic localization is also conferred by protein-protein interactions that promote its cytoplasmic retention. Indeed we found that in the cytoplasm, RanBPM partially colocalizes with microtubules and associates with α-tubulin. Finally, in the nucleus, a significant fraction of RanBPM is associated with chromatin. Altogether, these analyses reveal that RanBPM subcellular localization results from the combined effects of several elements that either confer direct transport through the nucleocytoplasmic transport machinery or regulate it indirectly, likely through interactions with other proteins and by intramolecular folding.
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Affiliation(s)
- Louisa M. Salemi
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Sandra O. Loureiro
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Caroline Schild-Poulter
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
- * E-mail:
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