1
|
Randolph K, Hyder U, Challa A, Perez E, D’Orso I. Functional Analysis of KAP1/TRIM28 Requirements for HIV-1 Transcription Activation. Viruses 2024; 16:116. [PMID: 38257816 PMCID: PMC10819576 DOI: 10.3390/v16010116] [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: 10/05/2023] [Revised: 12/13/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
HIV-1 latency maintenance and reactivation are regulated by several viral and host factors. One such factor is Krüppel-associated box (KRAB)-associated protein 1 (KAP1: also named TRIM28 or TIF1β). While initial studies have revealed KAP1 to be a positive regulator of latency reversal in transformed and primary CD4+ T cells, subsequent studies have proposed KAP1 to be a repressor required for latency maintenance. Given this discrepancy, in this study, we re-examine KAP1 transcription regulatory functions using a chemical genetics strategy to acutely deplete KAP1 expression to avoid the accumulation of indirect effects. Notably, KAP1 acute loss partially decreased HIV-1 promoter activity in response to activating signals, a function that can be restored upon complementation with exogenous KAP1, thus revealing that KAP1-mediated activation is on target. By combining comprehensive KAP1 domain deletion and mutagenesis in a cell-based reporter assay, we genetically defined the RING finger domain and an Intrinsically Disordered Region as key activating features. Together, our study solidifies the notion that KAP1 activates HIV-1 transcription by exploiting its multi-domain protein arrangement via previously unknown domains and functions.
Collapse
Affiliation(s)
| | | | | | | | - Iván D’Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (K.R.); (U.H.)
| |
Collapse
|
2
|
Pasha T, Zatorska A, Sharipov D, Rogelj B, Hortobágyi T, Hirth F. Karyopherin abnormalities in neurodegenerative proteinopathies. Brain 2021; 144:2915-2932. [PMID: 34019093 PMCID: PMC8194669 DOI: 10.1093/brain/awab201] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 04/08/2021] [Accepted: 05/11/2021] [Indexed: 11/12/2022] Open
Abstract
Neurodegenerative proteinopathies are characterized by progressive cell loss that is preceded by the mislocalization and aberrant accumulation of proteins prone to aggregation. Despite their different physiological functions, disease-related proteins like tau, α-synuclein, TAR DNA binding protein-43, fused in sarcoma and mutant huntingtin, all share low complexity regions that can mediate their liquid-liquid phase transitions. The proteins' phase transitions can range from native monomers to soluble oligomers, liquid droplets and further to irreversible, often-mislocalized aggregates that characterize the stages and severity of neurodegenerative diseases. Recent advances into the underlying pathogenic mechanisms have associated mislocalization and aberrant accumulation of disease-related proteins with defective nucleocytoplasmic transport and its mediators called karyopherins. These studies identify karyopherin abnormalities in amyotrophic lateral sclerosis, frontotemporal dementia, Alzheimer's disease, and synucleinopathies including Parkinson's disease and dementia with Lewy bodies, that range from altered expression levels to the subcellular mislocalization and aggregation of karyopherin α and β proteins. The reported findings reveal that in addition to their classical function in nuclear import and export, karyopherins can also act as chaperones by shielding aggregation-prone proteins against misfolding, accumulation and irreversible phase-transition into insoluble aggregates. Karyopherin abnormalities can, therefore, be both the cause and consequence of protein mislocalization and aggregate formation in degenerative proteinopathies. The resulting vicious feedback cycle of karyopherin pathology and proteinopathy identifies karyopherin abnormalities as a common denominator of onset and progression of neurodegenerative disease. Pharmacological targeting of karyopherins, already in clinical trials as therapeutic intervention targeting cancers such as glioblastoma and viral infections like COVID-19, may therefore represent a promising new avenue for disease-modifying treatments in neurodegenerative proteinopathies.
Collapse
Affiliation(s)
- Terouz Pasha
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| | - Anna Zatorska
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| | - Daulet Sharipov
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| | - Boris Rogelj
- Jozef Stefan Institute, Department of Biotechnology, 1000 Ljubljana, Slovenia
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, 1000 Ljubljana, Slovenia
| | - Tibor Hortobágyi
- ELKH-DE Cerebrovascular and Neurodegenerative Research Group, Department of Neurology, University of Debrecen, 4032 Debrecen, Hungary
- King's College London, Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, London SE5 8AF, UK
| | - Frank Hirth
- King’s College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, London SE5 9RT, UK
| |
Collapse
|
3
|
Jibiki K, Kodama TS, Suenaga A, Kawase Y, Shibazaki N, Nomoto S, Nagasawa S, Nagashima M, Shimodan S, Kikuchi R, Okayasu M, Takashita R, Mehmood R, Saitoh N, Yoneda Y, Akagi KI, Yasuhara N. Importin α2 association with chromatin: Direct DNA binding via a novel DNA-binding domain. Genes Cells 2021; 26:945-966. [PMID: 34519142 DOI: 10.1111/gtc.12896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/10/2021] [Accepted: 09/11/2021] [Indexed: 12/18/2022]
Abstract
The nuclear transport of proteins is important for facilitating appropriate nuclear functions. The importin α family proteins play key roles in nuclear transport as transport receptors for copious nuclear proteins. Additionally, these proteins possess other functions, including chromatin association and gene regulation. However, these nontransport functions of importin α are not yet fully understood, especially their molecular-level mechanisms and consequences for functioning with chromatin. Here, we report the novel molecular characteristics of importin α binding to diverse DNA sequences in chromatin. We newly identified and characterized a DNA-binding domain-the Nucleic Acid Associating Trolley pole domain (NAAT domain)-in the N-terminal region of importin α within the conventional importin β binding (IBB) domain that is necessary for nuclear transport of cargo proteins. Furthermore, we found that the DNA binding of importin α synergistically coupled the recruitment of its cargo protein to DNA. This is the first study to delineate the interaction between importin α and chromatin DNA via the NAAT domain, indicating the bifunctionality of the importin α N-terminal region for nuclear transport and chromatin association.
Collapse
Affiliation(s)
- Kazuya Jibiki
- Graduate School of Integrated Basic Sciences, Nihon University, Tokyo, Japan
| | - Takashi S Kodama
- National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
| | - Atsushi Suenaga
- Graduate School of Integrated Basic Sciences, Nihon University, Tokyo, Japan.,Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Yota Kawase
- Graduate School of Integrated Basic Sciences, Nihon University, Tokyo, Japan
| | - Noriko Shibazaki
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Shin Nomoto
- Graduate School of Integrated Basic Sciences, Nihon University, Tokyo, Japan
| | - Seiya Nagasawa
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Misaki Nagashima
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Shieri Shimodan
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Renan Kikuchi
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Mina Okayasu
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Ruka Takashita
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | - Rashid Mehmood
- Department of Life Sciences, College of Science and General Studies, Alfaisal University, Riyadh, Saudi Arabia
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of JFCR, Tokyo, Japan
| | - Yoshihiro Yoneda
- National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
| | - Ken-Ichi Akagi
- National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan.,Environmental Metabolic Analysis Research Team, RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Noriko Yasuhara
- Graduate School of Integrated Basic Sciences, Nihon University, Tokyo, Japan.,Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| |
Collapse
|
4
|
Ma Y, Weng J, Wang N, Zhang Y, Minato N, Su L. A novel nuclear localization region in SIPA1 determines protein nuclear distribution and epirubicin-sensitivity of breast cancer cells. Int J Biol Macromol 2021; 180:718-728. [PMID: 33753200 DOI: 10.1016/j.ijbiomac.2021.03.101] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/26/2021] [Accepted: 03/17/2021] [Indexed: 01/03/2023]
Abstract
Signal-induced proliferation-associated protein 1 (SIPA1) is highly expressed and mainly located in the nucleus in some breast cancer cell lines and clinical tumor tissues. Previous study revealed that nuclear localization of SIPA1 is functionally involved in breast cancer metastasis in the lymphatic gland. In the current study, we identified a non-typical region (140-179aa) of SIPA1 as a novel nuclear localization region (NLR) which is crucial for translocating the proteins into the nucleus in HEK293 cells and breast cancer cells. This region contained one basic amino acid, His160, and had no common features of typical nuclear localization signals. In addition, overexpressing SIPA1 without NLR could suppress breast cancer cell proliferation but could not promote cell migration in MCF7 cells. Furthermore, we found that a high expression of SIPA1 upregulated the expression of ABCB1, encoding multi-drug resistance protein MDR1, and promoted the resistance to epirubicin in breast cancer cells, while this effect was largely abolished in the cells with the expression of NLR-deleted SIPA1. This study overall, identified a nuclear localization-dependent region determining the nuclear distribution of SIPA1 and its regulation on epirubicin-sensitivity in breast cancer cells, which could be a potential drug target to facilitate the development of breast cancer chemotherapy.
Collapse
Affiliation(s)
- Ying Ma
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jun Weng
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ning Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yilei Zhang
- Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Nagahiro Minato
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Li Su
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
| |
Collapse
|
5
|
Moriyama T, Yoneda Y, Oka M, Yamada M. Transportin-2 plays a critical role in nucleocytoplasmic shuttling of oestrogen receptor-α. Sci Rep 2020; 10:18640. [PMID: 33122699 PMCID: PMC7596556 DOI: 10.1038/s41598-020-75631-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/16/2020] [Indexed: 12/15/2022] Open
Abstract
Oestrogen receptor-α (ERα) shuttles continuously between the nucleus and the cytoplasm, and functions as an oestrogen-dependent transcription factor in the nucleus and as an active mediator of signalling pathways, such as phosphatidylinositol 3-kinase (PI3K)/AKT, in the cytoplasm. However, little is known regarding the mechanism of ERα nucleocytoplasmic shuttling. In this study, we found that ERα is transported into the nucleus by importin-α/β1. Furthermore, we found that Transportin-2 (TNPO2) is involved in 17β-oestradiol (E2)-dependent cytoplasmic localisation of ERα. Interestingly, it was found that TNPO2 does not mediate nuclear export, but rather is involved in the cytoplasmic retention of ERα via the proline/tyrosine (PY) motifs. Moreover, we found that TNPO2 competitively binds to the basic nuclear localisation signal (NLS) of ERα with importin-α to inhibit importin-α/β-dependent ERα nuclear import. Finally, we confirmed that TNPO2 knockdown enhances the nuclear localisation of wild-type ERα and reduces PI3K/AKT phosphorylation in the presence of E2. These results reveal that TNPO2 regulates nucleocytoplasmic shuttling and cytoplasmic retention of ERα, so that ERα has precise functions depending on the stimulation.
Collapse
Affiliation(s)
- Tetsuji Moriyama
- Department of Cell Biology and Biochemistry, Division of Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka Shimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Yoshihiro Yoneda
- Health and Nutrition (NIBIOHN), National Institutes of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan.,Laboratory of Nuclear Transport Dynamics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Masahiro Oka
- Laboratory of Nuclear Transport Dynamics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan.,Laboratory of Nuclear Transport Dynamics, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), 7-6-8 Saito-Asagi, Ibaraki, Osaka, 567-0085, Japan
| | - Masami Yamada
- Department of Cell Biology and Biochemistry, Division of Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka Shimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan. .,Life Science Research Laboratory, University of Fukui, 23-3 Matsuoka Shimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
| |
Collapse
|
6
|
Vasquez V, Mitra J, Wang H, Hegde PM, Rao KS, Hegde ML. A multi-faceted genotoxic network of alpha-synuclein in the nucleus and mitochondria of dopaminergic neurons in Parkinson's disease: Emerging concepts and challenges. Prog Neurobiol 2020; 185:101729. [PMID: 31863801 PMCID: PMC7098698 DOI: 10.1016/j.pneurobio.2019.101729] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 10/15/2019] [Accepted: 11/18/2019] [Indexed: 02/06/2023]
Abstract
α-Synuclein is a hallmark amyloidogenic protein component of the Lewy bodies (LBs) present in dopaminergic neurons affected by Parkinson's disease (PD). Despite an enormous increase in emerging knowledge, the mechanism(s) of α-synuclein neurobiology and crosstalk among pathological events that are critical for PD progression remains enigmatic, creating a roadblock for effective intervention strategies. One confounding question is about the potential link between α-synuclein toxicity and genome instability in PD. We previously reported that pro-oxidant metal ions, together with reactive oxygen species (ROS), act as a "double whammy" in dopaminergic neurons by not only inducing genome damage but also inhibiting their repair. Our recent studies identified a direct role for chromatin-bound, oxidized α-synuclein in the induction of DNA strand breaks, which raised the question of a paradoxical role for α-synuclein's DNA binding in neuroprotection versus neurotoxicity. Furthermore, recent advances in our understanding of α-synuclein mediated mitochondrial dysfunction warrants revisiting the topics of α-synuclein pathophysiology in order to devise and assess the efficacy of α-synuclein-targeted interventions. In this review article, we discuss the multi-faceted neurotoxic role of α-synuclein in the nucleus and mitochondria with a particular emphasis on the role of α-synuclein in DNA damage/repair defects. We utilized a protein-DNA binding simulation to identify potential residues in α-synuclein that could mediate its binding to DNA and may be critical for its genotoxic functions. These emerging insights and paradigms may guide new drug targets and therapeutic modalities.
Collapse
Affiliation(s)
- Velmarini Vasquez
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA; Centre for Neuroscience, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, City of Knowledge, Panama
| | - Joy Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Haibo Wang
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA; Center for Neuroregeneration, Department of Neurosurgery, Methodist Neurological Institute, Institute of Academic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Pavana M Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - K S Rao
- Centre for Neuroscience, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, City of Knowledge, Panama
| | - Muralidhar L Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, 77030, USA; Center for Neuroregeneration, Department of Neurosurgery, Methodist Neurological Institute, Institute of Academic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA; Weill Cornell Medical College of Cornell University, New York, 10065, USA.
| |
Collapse
|
7
|
Abstract
It remains a significant challenge to define individual protein associations within networks where an individual protein can directly interact with other proteins and/or be part of large complexes, which contain functional modules. Here we demonstrate the topological scoring (TopS) algorithm for the analysis of quantitative proteomic datasets from affinity purifications. Data is analyzed in a parallel fashion where a prey protein is scored in an individual affinity purification by aggregating information from the entire dataset. Topological scores span a broad range of values indicating the enrichment of an individual protein in every bait protein purification. TopS is applied to interaction networks derived from human DNA repair proteins and yeast chromatin remodeling complexes. TopS highlights potential direct protein interactions and modules within complexes. TopS is a rapid method for the efficient and informative computational analysis of datasets, is complementary to existing analysis pipelines, and provides important insights into protein interaction networks. Inferring direct protein−protein interactions (PPIs) and modules in PPI networks remains a challenge. Here, the authors introduce an algorithm to infer potential direct PPIs from quantitative proteomic AP-MS data by identifying enriched interactions of each bait relative to the other baits.
Collapse
|
8
|
OKA M, YONEDA Y. Importin α: functions as a nuclear transport factor and beyond. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2018; 94:259-274. [PMID: 30078827 PMCID: PMC6117492 DOI: 10.2183/pjab.94.018] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Nucleocytoplasmic transport is an essential process in eukaryotes. The molecular mechanisms underlying nuclear transport that involve the nuclear transport receptor, small GTPase Ran, and the nuclear pore complex are highly conserved from yeast to humans. On the other hand, it has become clear that the nuclear transport system diverged during evolution to achieve various physiological functions in multicellular eukaryotes. In this review, we first summarize the molecular mechanisms of nuclear transport and how these were elucidated. Then, we focus on the diverse functions of importin α, which acts not merely an import factor but also as a multi-functional protein contributing to a variety of cellular functions in higher eukaryotes.
Collapse
Affiliation(s)
- Masahiro OKA
- National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
| | - Yoshihiro YONEDA
- National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
- Correspondence should be addressed: Y. Yoneda, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan (e-mail: )
| |
Collapse
|
9
|
Vasquez V, Mitra J, Hegde PM, Pandey A, Sengupta S, Mitra S, Rao KS, Hegde ML. Chromatin-Bound Oxidized α-Synuclein Causes Strand Breaks in Neuronal Genomes in in vitro Models of Parkinson's Disease. J Alzheimers Dis 2017; 60:S133-S150. [PMID: 28731447 PMCID: PMC6172953 DOI: 10.3233/jad-170342] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alpha-synuclein (α-Syn) overexpression and misfolding/aggregation in degenerating dopaminergic neurons have long been implicated in Parkinson's disease (PD). The neurotoxicity of α-Syn is enhanced by iron (Fe) and other pro-oxidant metals, leading to generation of reactive oxygen species in PD brain. Although α-Syn is predominantly localized in presynaptic nerve terminals, a small fraction exists in neuronal nuclei. However, the functional and/or pathological role of nuclear α-Syn is unclear. Following up on our earlier report that α-Syn directly binds DNA in vitro, here we confirm the nuclear localization and chromatin association of α-Syn in neurons using proximity ligation and chromatin immunoprecipitation analysis. Moderate (∼2-fold) increase in α-Syn expression in neural lineage progenitor cells (NPC) derived from induced pluripotent human stem cells (iPSCs) or differentiated SHSY-5Y cells caused DNA strand breaks in the nuclear genome, which was further enhanced synergistically by Fe salts. Furthermore, α-Syn required nuclear localization for inducing genome damage as revealed by the effect of nucleus versus cytosol-specific mutants. Enhanced DNA damage by oxidized and misfolded/oligomeric α-Syn suggests that DNA nicking activity is mediated by the chemical nuclease activity of an oxidized peptide segment in the misfolded α-Syn. Consistent with this finding, a marked increase in Fe-dependent DNA breaks was observed in NPCs from a PD patient-derived iPSC line harboring triplication of the SNCA gene. Finally, α-Syn combined with Fe significantly promoted neuronal cell death. Together, these findings provide a novel molecular insight into the direct role of α-Syn in inducing neuronal genome damage, which could possibly contribute to neurodegeneration in PD.
Collapse
Affiliation(s)
- Velmarini Vasquez
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
- Centre for Neuroscience, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, City of Knowledge, Republic of Panama
- Department of Biotechnology, Acharya Nagarjuna University, Guntur, India
| | - Joy Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Pavana M. Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Arvind Pandey
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
| | - Shiladitya Sengupta
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medical College of Cornell University, NY, USA
| | - Sankar Mitra
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medical College of Cornell University, NY, USA
| | - K. S. Rao
- Centre for Neuroscience, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología, City of Knowledge, Republic of Panama
| | - Muralidhar L. Hegde
- Department of Radiation Oncology, Houston Methodist Research Institute, Houston, TX, USA
- Houston Methodist Neurological Institute, Institute of Academic Medicine, Houston Methodist Hospital, Houston, TX, USA
- Weill Cornell Medical College of Cornell University, NY, USA
| |
Collapse
|
10
|
Sun Y, Xian L, Xing H, Yu J, Yang Z, Yang T, Yang L, Ding P. Factors influencing the nuclear targeting ability of nuclear localization signals. J Drug Target 2016; 24:927-933. [DOI: 10.1080/1061186x.2016.1184273] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|