1
|
Fujino Y, Ueyama M, Ishiguro T, Ozawa D, Ito H, Sugiki T, Murata A, Ishiguro A, Gendron T, Mori K, Tokuda E, Taminato T, Konno T, Koyama A, Kawabe Y, Takeuchi T, Furukawa Y, Fujiwara T, Ikeda M, Mizuno T, Mochizuki H, Mizusawa H, Wada K, Ishikawa K, Onodera O, Nakatani K, Petrucelli L, Taguchi H, Nagai Y. FUS regulates RAN translation through modulating the G-quadruplex structure of GGGGCC repeat RNA in C9orf72-linked ALS/FTD. eLife 2023; 12:RP84338. [PMID: 37461319 PMCID: PMC10393046 DOI: 10.7554/elife.84338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023] Open
Abstract
Abnormal expansions of GGGGCC repeat sequence in the noncoding region of the C9orf72 gene is the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). The expanded repeat sequence is translated into dipeptide repeat proteins (DPRs) by noncanonical repeat-associated non-AUG (RAN) translation. Since DPRs play central roles in the pathogenesis of C9-ALS/FTD, we here investigate the regulatory mechanisms of RAN translation, focusing on the effects of RNA-binding proteins (RBPs) targeting GGGGCC repeat RNAs. Using C9-ALS/FTD model flies, we demonstrated that the ALS/FTD-linked RBP FUS suppresses RAN translation and neurodegeneration in an RNA-binding activity-dependent manner. Moreover, we found that FUS directly binds to and modulates the G-quadruplex structure of GGGGCC repeat RNA as an RNA chaperone, resulting in the suppression of RAN translation in vitro. These results reveal a previously unrecognized regulatory mechanism of RAN translation by G-quadruplex-targeting RBPs, providing therapeutic insights for C9-ALS/FTD and other repeat expansion diseases.
Collapse
Grants
- Scientific Research on Innovative Areas (Brain Protein Aging and Dementia Control) 17H05699 Ministry of Education, Culture, Sports, Science and Technology
- Scientific Research on Innovative Areas (Brain Protein Aging and Dementia Control) 17H05705 Ministry of Education, Culture, Sports, Science and Technology
- Transformative Research Areas (A) (Multifaceted Proteins) 20H05927 Ministry of Education, Culture, Sports, Science and Technology
- Strategic Research Program for Brain Sciences 11013026 Ministry of Education, Culture, Sports, Science and Technology
- Scientific Research (B) 21H02840 Japan Society for the Promotion of Science
- Scientific Research (B) 20H03602 Japan Society for the Promotion of Science
- Scientific Research (C) 15K09331 Japan Society for the Promotion of Science
- Scientific Research (C) 19K07823 Japan Society for the Promotion of Science
- Scientific Research (C) 17K07291 Japan Society for the Promotion of Science
- Young Scientists (A) 17H05091 Japan Society for the Promotion of Science
- Young Scientists (B) 25860733 Japan Society for the Promotion of Science
- Challenging Exploratory Research 24659438 Japan Society for the Promotion of Science
- Challenging Exploratory Research 18K19515 Japan Society for the Promotion of Science
- Health Labor Sciences Research Grant for Research on Development of New Drugs H24-Soyaku-Sogo-002 Ministry of Health, Labor and Welfare, Japan
- Strategic Research Program for Brain Sciences JP15dm0107026 Japan Agency for Medical Research and Development
- Strategic Research Program for Brain Sciences JP20dm0107061 Japan Agency for Medical Research and Development
- Practical Research Projects for Rare/Intractable Diseases JP16ek0109018 Japan Agency for Medical Research and Development
- Practical Research Projects for Rare/Intractable Diseases JP19ek0109222 Japan Agency for Medical Research and Development
- Practical Research Projects for Rare/Intractable Diseases JP20ek0109316 Japan Agency for Medical Research and Development
- Platform Project for Supporting Drug Discovery and Life Science Research JP19am0101072 Japan Agency for Medical Research and Development
- Intramural Research Grants for Neurological and Psychiatric Disorders 27-7 National Center of Neurology and Psychiatry
- Intramural Research Grants for Neurological and Psychiatric Disorders 27-9 National Center of Neurology and Psychiatry
- Intramural Research Grants for Neurological and Psychiatric Disorders 30-3 National Center of Neurology and Psychiatry
- Intramural Research Grants for Neurological and Psychiatric Disorders 30-9 National Center of Neurology and Psychiatry
- Intramural Research Grants for Neurological and Psychiatric Disorders 3-9 National Center of Neurology and Psychiatry
- IBC Grant H28 Japan Amyotrophic Lateral Sclerosis Association
- 2017 Takeda Science Foundation
- 2016 Takeda Science Foundation
- 2018 SENSHIN Medical Research Foundation
Collapse
Affiliation(s)
- Yuzo Fujino
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Morio Ueyama
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Taro Ishiguro
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Daisaku Ozawa
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hayato Ito
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Toshihiko Sugiki
- Laboratory of Molecular Biophysics, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Asako Murata
- Department of Regulatory Bioorganic Chemistry, The Institute of Scientific and28 Industrial Research, Osaka University, Osaka, Japan
| | - Akira Ishiguro
- Research Center for Micro-nano Technology, Hosei University, Tokyo, Japan
| | - Tania Gendron
- Department of Neuroscience, Mayo Clinic, Jacksonville, United States
| | - Kohji Mori
- Department of Psychiatry, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Eiichi Tokuda
- Department of Chemistry, Keio University, Kanagawa, Japan
| | - Tomoya Taminato
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takuya Konno
- Department of Neurology, Clinical Neuroscience Branch, Brain Research Institute, Niigata University, Niigata, Japan
| | - Akihide Koyama
- Department of Neurology, Clinical Neuroscience Branch, Brain Research Institute, Niigata University, Niigata, Japan
| | - Yuya Kawabe
- Department of Psychiatry, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Toshihide Takeuchi
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Japan
- Life Science Research Institute, Kindai University, Osaka, Japan
| | | | - Toshimichi Fujiwara
- Laboratory of Molecular Biophysics, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Manabu Ikeda
- Department of Psychiatry, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Toshiki Mizuno
- Department of Neurology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Hidehiro Mizusawa
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Keiji Wada
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Kinya Ishikawa
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Tokyo, Japan
| | - Osamu Onodera
- Department of Neurology, Clinical Neuroscience Branch, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kazuhiko Nakatani
- Department of Regulatory Bioorganic Chemistry, The Institute of Scientific and28 Industrial Research, Osaka University, Osaka, Japan
| | | | - Hideki Taguchi
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Kanagawa, Japan
| | - Yoshitaka Nagai
- Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
- Department of Neurotherapeutics, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| |
Collapse
|
2
|
Sending the message: specialized RNA export mechanisms in trypanosomes. Trends Parasitol 2022; 38:854-867. [PMID: 36028415 PMCID: PMC9894534 DOI: 10.1016/j.pt.2022.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 07/25/2022] [Accepted: 07/25/2022] [Indexed: 02/04/2023]
Abstract
Export of RNA from the nucleus is essential for all eukaryotic cells and has emerged as a major step in the control of gene expression. mRNA molecules are required to complete a complex series of processing events and pass a quality control system to protect the cytoplasm from the translation of aberrant proteins. Many of these events are highly conserved across eukaryotes, reflecting their ancient origin, but significant deviation from a canonical pathway as described from animals and fungi has emerged in the trypanosomatids. With significant implications for the mechanisms that control gene expression and hence differentiation, responses to altered environments and fitness as a parasite, these deviations may also reveal additional, previously unsuspected, mRNA export pathways.
Collapse
|
3
|
Heterogeneous nuclear ribonucleoprotein A/B: an emerging group of cancer biomarkers and therapeutic targets. Cell Death Dis 2022; 8:337. [PMID: 35879279 PMCID: PMC9314375 DOI: 10.1038/s41420-022-01129-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 11/20/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein A/B (hnRNPA/B) is one of the core members of the RNA binding protein (RBP) hnRNPs family, including four main subtypes, A0, A1, A2/B1 and A3, which share the similar structure and functions. With the advance in understanding the molecular biology of hnRNPA/B, it has been gradually revealed that hnRNPA/B plays a critical role in almost the entire steps of RNA life cycle and its aberrant expression and mutation have important effects on the occurrence and progression of various cancers. This review focuses on the clinical significance of hnRNPA/B in various cancers and systematically summarizes its biological function and molecular mechanisms.
Collapse
|
4
|
Cellular Stress Induces Nucleocytoplasmic Transport Deficits Independent of Stress Granules. Biomedicines 2022; 10:biomedicines10051057. [PMID: 35625794 PMCID: PMC9138870 DOI: 10.3390/biomedicines10051057] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 02/05/2023] Open
Abstract
Stress granules are non-membrane bound granules temporarily forming in the cytoplasm in response to stress. Proteins of the nucleocytoplasmic transport machinery were found in these stress granules and it was suggested that stress granules contribute to the nucleocytoplasmic transport defects in several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). The aim of this study was to investigate whether there is a causal link between stress granule formation and nucleocytoplasmic transport deficits. Therefore, we uncoupled stress granule formation from cellular stress while studying nuclear import. This was carried out by preventing cells from assembling stress granules despite being subjected to cellular stress either by knocking down both G3BP1 and G3BP2 or by pharmacologically inhibiting stress granule formation. Conversely, we induced stress granules by overexpressing G3BP1 in the absence of cellular stress. In both conditions, nuclear import was not affected demonstrating that stress granule formation is not a direct cause of stress-induced nucleocytoplasmic transport deficits.
Collapse
|
5
|
Vanneste J, Van Den Bosch L. The Role of Nucleocytoplasmic Transport Defects in Amyotrophic Lateral Sclerosis. Int J Mol Sci 2021; 22:12175. [PMID: 34830069 PMCID: PMC8620263 DOI: 10.3390/ijms222212175] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/10/2021] [Accepted: 10/14/2021] [Indexed: 12/24/2022] Open
Abstract
There is ample evidence that nucleocytoplasmic-transport deficits could play an important role in the pathology of amyotrophic lateral sclerosis (ALS). However, the currently available data are often circumstantial and do not fully clarify the exact causal and temporal role of nucleocytoplasmic transport deficits in ALS patients. Gaining this knowledge will be of great significance in order to be able to target therapeutically nucleocytoplasmic transport and/or the proteins involved in this process. The availability of good model systems to study the nucleocytoplasmic transport process in detail will be especially crucial in investigating the effect of different mutations, as well as of other forms of stress. In this review, we discuss the evidence for the involvement of nucleocytoplasmic transport defects in ALS and the methods used to obtain these data. In addition, we provide an overview of the therapeutic strategies which could potentially counteract these defects.
Collapse
Affiliation(s)
- Joni Vanneste
- Experimental Neurology, Department of Neurosciences and Leuven Brain Institute (LBI), KU Leuven–University of Leuven, B-3000 Leuven, Belgium;
- Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, B-3000 Leuven, Belgium
| | - Ludo Van Den Bosch
- Experimental Neurology, Department of Neurosciences and Leuven Brain Institute (LBI), KU Leuven–University of Leuven, B-3000 Leuven, Belgium;
- Laboratory of Neurobiology, Center for Brain & Disease Research, VIB, B-3000 Leuven, Belgium
| |
Collapse
|
6
|
Thibault PA, Ganesan A, Kalyaanamoorthy S, Clarke JPWE, Salapa HE, Levin MC. hnRNP A/B Proteins: An Encyclopedic Assessment of Their Roles in Homeostasis and Disease. BIOLOGY 2021; 10:biology10080712. [PMID: 34439945 PMCID: PMC8389229 DOI: 10.3390/biology10080712] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 12/13/2022]
Abstract
The hnRNP A/B family of proteins is canonically central to cellular RNA metabolism, but due to their highly conserved nature, the functional differences between hnRNP A1, A2/B1, A0, and A3 are often overlooked. In this review, we explore and identify the shared and disparate homeostatic and disease-related functions of the hnRNP A/B family proteins, highlighting areas where the proteins have not been clearly differentiated. Herein, we provide a comprehensive assembly of the literature on these proteins. We find that there are critical gaps in our grasp of A/B proteins' alternative splice isoforms, structures, regulation, and tissue and cell-type-specific functions, and propose that future mechanistic research integrating multiple A/B proteins will significantly improve our understanding of how this essential protein family contributes to cell homeostasis and disease.
Collapse
Affiliation(s)
- Patricia A. Thibault
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
| | - Aravindhan Ganesan
- ArGan’s Lab, School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - Subha Kalyaanamoorthy
- Department of Chemistry, Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - Joseph-Patrick W. E. Clarke
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Hannah E. Salapa
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
| | - Michael C. Levin
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Correspondence:
| |
Collapse
|
7
|
Connecting the "dots": RNP granule network in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119058. [PMID: 33989700 DOI: 10.1016/j.bbamcr.2021.119058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 05/01/2021] [Accepted: 05/07/2021] [Indexed: 12/26/2022]
Abstract
All cells contain ribonucleoprotein (RNP) granules - large membraneless structures composed of RNA and proteins. Recent breakthroughs in RNP granule research have brought a new appreciation of their crucial role in organising virtually all cellular processes. Cells widely exploit the flexible, dynamic nature of RNP granules to adapt to a variety of functional states and the ever-changing environment. Constant exchange of molecules between the different RNP granules connects them into a network. This network controls basal cellular activities and is remodelled to enable efficient stress response. Alterations in RNP granule structure and regulation have been found to lead to fatal human diseases. The interconnectedness of RNP granules suggests that the RNP granule network as a whole becomes affected in disease states such as a representative neurodegenerative disease amyotrophic lateral sclerosis (ALS). In this review, we summarize available evidence on the communication between different RNP granules and on the RNP granule network disruption as a primary ALS pathomechanism.
Collapse
|
8
|
Profiling of subcellular EGFR interactome reveals hnRNP A3 modulates nuclear EGFR localization. Oncogenesis 2020; 9:40. [PMID: 32321917 PMCID: PMC7176650 DOI: 10.1038/s41389-020-0225-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/04/2020] [Accepted: 04/07/2020] [Indexed: 12/19/2022] Open
Abstract
The aberrant subcellular translocation and distribution of epidermal growth factor receptor (EGFR) represent a major yet currently underappreciated cancer development mechanism in non-small cell lung cancer (NSCLC). In this study, we investigated the subcellular interactome of EGFR by using a spectral counting-based approach combined with liquid chromatography–tandem mass spectrometry to understand the associated protein networks involved in the tumorigenesis of NSCLC. A total of 54, 77, and 63 EGFR-interacting proteins were identified specifically in the cytosolic, mitochondrial, and nuclear fractions from a NSCLC cell line, respectively. Pathway analyses of these proteins using the KEGG database shown that the EGFR-interacting proteins of the cytosol and nucleus are involved in the ribosome and spliceosome pathways, respectively, while those of the mitochondria are involved in metabolizing propanoate, fatty acid, valine, leucine, and isoleucine. A selected nuclear EGFR-interacting protein, hnRNP A3, was found to modulate the accumulation of nuclear EGFR. Downregulation of hnRNP A3 reduced the nuclear accumulation of EGFR, and this was accompanied by reduced tumor growth ability in vitro and in vivo. These results indicate that variations in the subcellular translocation and distribution of EGFR within NSCLC cells could affect tumor progression.
Collapse
|
9
|
Mishra N, Reddy KS, Timilsina U, Gaur D, Gaur R. Human APOBEC3B interacts with the heterogenous nuclear ribonucleoprotein A3 in cancer cells. J Cell Biochem 2018; 119:6695-6703. [PMID: 29693745 DOI: 10.1002/jcb.26855] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 03/09/2018] [Indexed: 11/07/2022]
Abstract
Human APOBEC3B (A3B), like other APOBEC3 members, is a cytosine deaminase which causes hypermutation of single stranded genome. Recent studies have shown that A3B is predominantly elevated in multiple cancer tissues and cell lines such as the bladder, cervix, lung, head and neck, and breast. Upregulation and activation of A3B in developing tumors can cause an unexpected cluster of mutations which promote cancer development and progression. The cellular proteins which facilitate A3B function through direct or indirect interactions remain largely unknown. In this study, we performed LC-MS-based proteomics to identify cellular proteins which coimmunoprecipitated with A3B. Our results indicated a specific interaction of A3B with hnRNP A3 (heterogeneous nuclear ribonucleoprotein). This interaction was verified by co-immunoprecipitation and was found to be RNA-dependent. Furthermore, A3B and hnRNP A3 colocalized as evident from immunofluorescence analysis.
Collapse
Affiliation(s)
- Nawneet Mishra
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
| | - K Sony Reddy
- School of Biotechnology, KIIT University, Odisha, India
| | - Uddhav Timilsina
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
| | - Deepak Gaur
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Ritu Gaur
- Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi, India
| |
Collapse
|
10
|
Rekosh D, Hammarskjold ML. Intron retention in viruses and cellular genes: Detention, border controls and passports. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1470. [PMID: 29508942 DOI: 10.1002/wrna.1470] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 01/04/2018] [Accepted: 01/24/2018] [Indexed: 02/06/2023]
Abstract
Intron retention (IR), where one or more introns remain in the RNA after splicing, was long thought to be rare in mammalian cells, albeit common in plants and some viruses. Largely due to the development of better methods for RNA analysis, it has now been recognized that IR is much more common than previously thought and that this mechanism is likely to play an important role in mammalian gene regulation. To date, most publications and reviews about IR have described the resulting mRNAs as "dead end" products, with no direct consequence for the proteome. However, there are also many reports of mRNAs with retained introns giving rise to alternative protein isoforms. Although this was originally revealed in viral systems, there are now numerous examples of bona fide cellular proteins that are translated from mRNAs with retained introns. These new isoforms have sometimes been shown to have important regulatory functions. In this review, we highlight recent developments in this area and the research on viruses that led the way to the realization of the many ways in which mRNAs with retained introns can be regulated. This article is categorized under: RNA Processing > Splicing Mechanisms RNA Processing > Splicing Regulation/Alternative Splicing RNA Export and Localization > Nuclear Export/Import RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
Collapse
Affiliation(s)
- David Rekosh
- The Myles H. Thaler Center for AIDS and Human Retrovirus Research and the Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia.,Department of Microbiology, University of Venda, Thohoyandou, South Africa
| | - Marie-Louise Hammarskjold
- The Myles H. Thaler Center for AIDS and Human Retrovirus Research and the Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia.,Department of Microbiology, University of Venda, Thohoyandou, South Africa
| |
Collapse
|
11
|
Li MW, Sletten AC, Lee J, Pyles KD, Matkovich SJ, Ory DS, Schaffer JE. Nuclear export factor 3 regulates localization of small nucleolar RNAs. J Biol Chem 2017; 292:20228-20239. [PMID: 29021253 DOI: 10.1074/jbc.m117.818146] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 10/05/2017] [Indexed: 01/04/2023] Open
Abstract
Small nucleolar RNAs (snoRNAs) guide chemical modifications of ribosomal and small nuclear RNAs, functions that are carried out in the nucleus. Although most snoRNAs reside in the nucleolus, a growing body of evidence indicates that snoRNAs are also present in the cytoplasm and that snoRNAs move between the nucleus and cytoplasm by a mechanism that is regulated by lipotoxic and oxidative stress. Here, in a genome-wide shRNA-based screen, we identified nuclear export factor 3 (NXF3) as a transporter that alters the nucleocytoplasmic distribution of box C/D snoRNAs from the ribosomal protein L13a (Rpl13a) locus. Using RNA-sequencing analysis, we show that NXF3 associates not only with Rpl13a snoRNAs, but also with a broad range of box C/D and box H/ACA snoRNAs. Under homeostatic conditions, gain- or loss-of-function of NXF3, but not related family member NXF1, decreases or increases cytosolic Rpl13a snoRNAs, respectively. Furthermore, treatment with the adenylyl cyclase activator forskolin diminishes cytosolic localization of the Rpl13a snoRNAs through a mechanism that is dependent on NXF3 but not NXF1. Our results provide evidence of a new role for NXF3 in regulating the distribution of snoRNAs between the nuclear and cytoplasmic compartments.
Collapse
Affiliation(s)
- Melissa W Li
- Diabetes Research Center, Department of Medicine, St. Louis, Missouri 63110
| | - Arthur C Sletten
- Diabetes Research Center, Department of Medicine, St. Louis, Missouri 63110
| | - Jiyeon Lee
- Diabetes Research Center, Department of Medicine, St. Louis, Missouri 63110
| | - Kelly D Pyles
- Diabetes Research Center, Department of Medicine, St. Louis, Missouri 63110
| | - Scot J Matkovich
- Center for Cardiovascular Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Daniel S Ory
- Diabetes Research Center, Department of Medicine, St. Louis, Missouri 63110
| | - Jean E Schaffer
- Diabetes Research Center, Department of Medicine, St. Louis, Missouri 63110.
| |
Collapse
|
12
|
Budini M, Buratti E, Morselli E, Criollo A. Autophagy and Its Impact on Neurodegenerative Diseases: New Roles for TDP-43 and C9orf72. Front Mol Neurosci 2017; 10:170. [PMID: 28611593 PMCID: PMC5447761 DOI: 10.3389/fnmol.2017.00170] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/15/2017] [Indexed: 12/12/2022] Open
Abstract
Autophagy is a catabolic mechanism where intracellular material is degraded by vesicular structures called autophagolysosomes. Autophagy is necessary to maintain the normal function of the central nervous system (CNS), avoiding the accumulation of misfolded and aggregated proteins. Consistently, impaired autophagy has been associated with the pathogenesis of various neurodegenerative diseases. The proteins TAR DNA-binding protein-43 (TDP-43), which regulates RNA processing at different levels, and chromosome 9 open reading frame 72 (C9orf72), probably involved in membrane trafficking, are crucial in the development of neurodegenerative diseases such as Amyotrophic lateral sclerosis (ALS) and Frontotemporal Lobar Degeneration (FTLD). Additionally, recent studies have identified a role for these proteins in the control of autophagy. In this manuscript, we review what is known regarding the autophagic mechanism and discuss the involvement of TDP-43 and C9orf72 in autophagy and their impact on neurodegenerative diseases.
Collapse
Affiliation(s)
- Mauricio Budini
- Dentistry Faculty, Institute in Dentistry Sciences, University of ChileSantiago, Chile
| | - Emanuele Buratti
- International Centre for Genetic Engineering and BiotechnologyTrieste, Italy
| | - Eugenia Morselli
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Alfredo Criollo
- Dentistry Faculty, Institute in Dentistry Sciences, University of ChileSantiago, Chile.,Advanced Center for Chronic DiseasesSantiago, Chile
| |
Collapse
|
13
|
Mamon LA, Ginanova VR, Kliver SF, Yakimova AO, Atsapkina AA, Golubkova EV. RNA-binding proteins of the NXF (nuclear export factor) family and their connection with the cytoskeleton. Cytoskeleton (Hoboken) 2017; 74:161-169. [PMID: 28296067 DOI: 10.1002/cm.21362] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/04/2017] [Accepted: 03/08/2017] [Indexed: 02/05/2023]
Abstract
The mutual relationship between mRNA and the cytoskeleton can be seen from two points of view. On the one hand, the cytoskeleton is necessary for mRNA trafficking and anchoring to subcellular domains. On the other hand, cytoskeletal growth and rearrangement require the translation of mRNAs that are connected to the cytoskeleton. β-actin mRNA localization may influence dynamic changes in the actin cytoskeleton. In the cytoplasm, long-lived mRNAs exist in the form of RNP (ribonucleoprotein) complexes, where they interact with RNA-binding proteins, including NXF (Nuclear eXport Factor). Dm NXF1 is an evolutionarily conserved protein in Drosophila melanogaster that has orthologs in different animals. The universal function of nxf1 genes is the nuclear export of different mRNAs in various organisms. In this mini-review, we briefly discuss the evidence demonstrating that Dm NXF1 fulfils not only universal but also specialized cytoplasmic functions. This protein is detected not only in the nucleus but also in the cytoplasm. It is a component of neuronal granules. Dm NXF1 marks nuclear division spindles during early embryogenesis and the dense body on one side of the elongated spermatid nuclei. The characteristic features of sbr mutants (sbr10 and sbr5 ) are impairment of chromosome segregation and spindle formation anomalies during female meiosis. sbr12 mutant sterile males with immobile spermatozoa exhibit disturbances in the axoneme, mitochondrial derivatives and cytokinesis. These data allow us to propose that the Dm NXF1 proteins transport certain mRNAs in neurites and interact with localized mRNAs that are necessary for dynamic changes of the cytoskeleton.
Collapse
Affiliation(s)
- L A Mamon
- Department of Genetics and Biotechnology, Faculty of Biology, St Petersburg State University Universitetskaya nab. 7-9, Saint-Petersburg, 199034, Russia
| | - V R Ginanova
- Department of Genetics and Biotechnology, Faculty of Biology, St Petersburg State University Universitetskaya nab. 7-9, Saint-Petersburg, 199034, Russia
| | - S F Kliver
- Department of Genetics and Biotechnology, Faculty of Biology, St Petersburg State University Universitetskaya nab. 7-9, Saint-Petersburg, 199034, Russia
| | - A O Yakimova
- Department of Genetics and Biotechnology, Faculty of Biology, St Petersburg State University Universitetskaya nab. 7-9, Saint-Petersburg, 199034, Russia
| | - A A Atsapkina
- Department of Genetics and Biotechnology, Faculty of Biology, St Petersburg State University Universitetskaya nab. 7-9, Saint-Petersburg, 199034, Russia
| | - E V Golubkova
- Department of Genetics and Biotechnology, Faculty of Biology, St Petersburg State University Universitetskaya nab. 7-9, Saint-Petersburg, 199034, Russia
| |
Collapse
|
14
|
Geuens T, De Winter V, Rajan N, Achsel T, Mateiu L, Almeida-Souza L, Asselbergh B, Bouhy D, Auer-Grumbach M, Bagni C, Timmerman V. Mutant HSPB1 causes loss of translational repression by binding to PCBP1, an RNA binding protein with a possible role in neurodegenerative disease. Acta Neuropathol Commun 2017; 5:5. [PMID: 28077174 PMCID: PMC5225548 DOI: 10.1186/s40478-016-0407-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/16/2016] [Indexed: 12/12/2022] Open
Abstract
The small heat shock protein HSPB1 (Hsp27) is an ubiquitously expressed molecular chaperone able to regulate various cellular functions like actin dynamics, oxidative stress regulation and anti-apoptosis. So far disease causing mutations in HSPB1 have been associated with neurodegenerative diseases such as distal hereditary motor neuropathy, Charcot-Marie-Tooth disease and amyotrophic lateral sclerosis. Most mutations in HSPB1 target its highly conserved α-crystallin domain, while other mutations affect the C- or N-terminal regions or its promotor. Mutations inside the α-crystallin domain have been shown to enhance the chaperone activity of HSPB1 and increase the binding to client proteins. However, the HSPB1-P182L mutation, located outside and downstream of the α-crystallin domain, behaves differently. This specific HSPB1 mutation results in a severe neuropathy phenotype affecting exclusively the motor neurons of the peripheral nervous system. We identified that the HSPB1-P182L mutant protein has a specifically increased interaction with the RNA binding protein poly(C)binding protein 1 (PCBP1) and results in a reduction of its translational repressive activity. RNA immunoprecipitation followed by RNA sequencing on mouse brain lead to the identification of PCBP1 mRNA targets. These targets contain larger 3′- and 5′-UTRs than average and are enriched in an RNA motif consisting of the CTCCTCCTCCTCC consensus sequence. Interestingly, next to the clear presence of neuronal transcripts among the identified PCBP1 targets we identified known genes associated with hereditary peripheral neuropathies and hereditary spastic paraplegias. We therefore conclude that HSPB1 can mediate translational repression through interaction with an RNA binding protein further supporting its role in neurodegenerative disease.
Collapse
|
15
|
Li Y, Bor YC, Fitzgerald MP, Lee KS, Rekosh D, Hammarskjold ML. An NXF1 mRNA with a retained intron is expressed in hippocampal and neocortical neurons and is translated into a protein that functions as an Nxf1 cofactor. Mol Biol Cell 2016; 27:3903-3912. [PMID: 27708137 PMCID: PMC5170612 DOI: 10.1091/mbc.e16-07-0515] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/14/2016] [Accepted: 09/26/2016] [Indexed: 12/22/2022] Open
Abstract
A small Nxf1 protein, expressed from an NXF1 mRNA with a retained intron is highly expressed in rodent hippocampal and neocortical neurons, colocalizes with Staufen2 proteins in neuronal RNA granules, is present in polysomes, and replaces Nxt1 as an Nxf1 cofactor in export and expression of mRNA with retained introns. The Nxf1 protein is a major nuclear export receptor for the transport of mRNA, and it also is essential for export of retroviral mRNAs with retained introns. In the latter case, it binds to RNA elements known as constitutive transport elements (CTEs) and functions in conjunction with a cofactor known as Nxt1. The NXF1 gene also regulates expression of its own intron-containing RNA through the use of a functional CTE within intron 10. mRNA containing this intron is exported to the cytoplasm, where it can be translated into the 356–amino acid short Nxf1(sNxf1) protein, despite the fact that it is a prime candidate for nonsense-mediated decay (NMD). Here we demonstrate that sNxf1 is highly expressed in nuclei and dendrites of hippocampal and neocortical neurons in rodent brain. Additionally, we show that sNxf1 localizes in RNA granules in neurites of differentiated N2a mouse neuroblastoma cells, where it shows partial colocalization with Staufen2 isoform SS, a protein known to play a role in dendritic mRNA trafficking. We also show that sNxf1 forms heterodimers in conjunction with the full-length Nxf1 and that sNxf1 can replace Nxt1 to enhance the expression of CTE-containing mRNA and promote its association with polyribosomes.
Collapse
Affiliation(s)
- Ying Li
- Myles H. Thaler Center for AIDS and Human Retrovirus Research and Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Yeou-Cherng Bor
- Myles H. Thaler Center for AIDS and Human Retrovirus Research and Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Mark P Fitzgerald
- Departments of Neuroscience and Neurosurgery, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Kevin S Lee
- Departments of Neuroscience and Neurosurgery, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - David Rekosh
- Myles H. Thaler Center for AIDS and Human Retrovirus Research and Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for AIDS and Human Retrovirus Research and Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908
| |
Collapse
|
16
|
Yakimova AO, Pugacheva OM, Golubkova EV, Mamon LA. Cytoplasmic localization of SBR (Dm NXF1) protein and its zonal distribution in the ganglia of Drosophila melanogaster larvae. INVERTEBRATE NEUROSCIENCE 2016; 16:9. [DOI: 10.1007/s10158-016-0192-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 06/24/2016] [Indexed: 10/21/2022]
|
17
|
Poblete-Durán N, Prades-Pérez Y, Vera-Otarola J, Soto-Rifo R, Valiente-Echeverría F. Who Regulates Whom? An Overview of RNA Granules and Viral Infections. Viruses 2016; 8:v8070180. [PMID: 27367717 PMCID: PMC4974515 DOI: 10.3390/v8070180] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 12/22/2022] Open
Abstract
After viral infection, host cells respond by mounting an anti-viral stress response in order to create a hostile atmosphere for viral replication, leading to the shut-off of mRNA translation (protein synthesis) and the assembly of RNA granules. Two of these RNA granules have been well characterized in yeast and mammalian cells, stress granules (SGs), which are translationally silent sites of RNA triage and processing bodies (PBs), which are involved in mRNA degradation. This review discusses the role of these RNA granules in the evasion of anti-viral stress responses through virus-induced remodeling of cellular ribonucleoproteins (RNPs).
Collapse
Affiliation(s)
- Natalia Poblete-Durán
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| | - Yara Prades-Pérez
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| | - Jorge Vera-Otarola
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Centro de Investigaciones Médicas, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago 8330024, Chile.
| | - Ricardo Soto-Rifo
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| | - Fernando Valiente-Echeverría
- Molecular and Cellular Virology Laboratory, Virology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Independencia 1027, Santiago, 8389100, Chile.
| |
Collapse
|
18
|
Li H, Chen K, Wang Z, Li D, Lin J, Yu C, Yu F, Wang X, Huang L, Jiang C, Gu H, Fang J. Genetic analysis of the clonal stability of Chinese hamster ovary cells for recombinant protein production. MOLECULAR BIOSYSTEMS 2015; 12:102-9. [PMID: 26563441 DOI: 10.1039/c5mb00627a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chinese hamster ovary (CHO) cells are frequently used for the production of recombinant proteins for therapeutical applications. However, the recombinant protein expression level of CHO cells may reduce during long-term culture. The physiological changes related to the stability of expression were not well understood. In this study, we performed a series of genetic analysis on stable and unstable clonal derived populations. Transcriptome analysis revealed that a large number of differentially expressed genes (>100) were identified in the unstable population between early and late generations, while only a few differentially expressed genes were found in the stable population, suggesting that the gene expression change is related to the instability of recombinant protein production. On the other hand, no significant differences were found in promoter methylation or gene copy numbers in the unstable population. Taken together, our data help better understand the molecular mechanism underlying the stability of recombinant protein production in CHO cells.
Collapse
Affiliation(s)
- Hongwen Li
- School of Life Sciences and Technology, Tongji University, Shanghai, China.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Callaerts-Vegh Z, Ahmed T, Vermaercke B, Marynen P, Balschun D, Froyen G, D'Hooge R. Nxf7 deficiency impairs social exploration and spatio-cognitive abilities as well as hippocampal synaptic plasticity in mice. Front Behav Neurosci 2015. [PMID: 26217206 PMCID: PMC4498129 DOI: 10.3389/fnbeh.2015.00179] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nuclear RNA export factors (NXF) are conserved in all metazoans and are deemed essential for shuttling RNA across the nuclear envelope and other post-transcriptional processes (such as mRNA metabolism, storage and stability). Disruption of human NXF5 has been implicated in intellectual and psychosocial disabilities. In the present report, we use recently described Nxf7 knockout (KO) mice as an experimental model to analyze in detail the behavioral consequences of clinical NXF5 deficiency. We examined male Nxf7 KO mice using an extended cognitive and behavioral test battery, and recorded extracellular field potentials in the hippocampal CA1 region. We observed various cognitive and behavioral changes including alterations in social exploration, impaired spatial learning and spatio-cognitive abilities. We also defined a new experimental paradigm to discriminate search strategies in Morris water maze and showed significant differences between Nxf7 KO and control animals. Furthermore, while we observed no difference in a nose poke suppression in an conditioned emotional response (CER) protocol, Nxf7 KO mice were impaired in discriminating between differentially reinforced cues in an auditory fear conditioning protocol. This distinct neurocognitive phenotype was accompanied by impaired hippocampal Long-term potentiation (LTP), while long-term depression (LTD) was not affected by Nxf7 deficiency. Our data demonstrate that disruption of murine Nxf7 leads to behavioral phenotypes that may relate to the intellectual and social deficits in patients with NXF5 deficiency.
Collapse
Affiliation(s)
| | - Tariq Ahmed
- Laboratory of Biological Psychology, University of Leuven, KU Leuven Leuven, Belgium
| | - Ben Vermaercke
- Laboratory of Biological Psychology, University of Leuven, KU Leuven Leuven, Belgium
| | - Peter Marynen
- Human Genome Laboratory, University of Leuven and VIB Center for the Biology of Disease Leuven, Belgium
| | - Detlef Balschun
- Laboratory of Biological Psychology, University of Leuven, KU Leuven Leuven, Belgium
| | - Guy Froyen
- Human Genome Laboratory, University of Leuven and VIB Center for the Biology of Disease Leuven, Belgium
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, University of Leuven, KU Leuven Leuven, Belgium
| |
Collapse
|
20
|
Nuclear export of messenger RNA. Genes (Basel) 2015; 6:163-84. [PMID: 25836925 PMCID: PMC4488659 DOI: 10.3390/genes6020163] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 11/29/2022] Open
Abstract
Transport of messenger RNA (mRNA) from the nucleus to the cytoplasm is an essential step of eukaryotic gene expression. In the cell nucleus, a precursor mRNA undergoes a series of processing steps, including capping at the 5' ends, splicing and cleavage/polyadenylation at the 3' ends. During this process, the mRNA associates with a wide variety of proteins, forming a messenger ribonucleoprotein (mRNP) particle. Association with factors involved in nuclear export also occurs during transcription and processing, and thus nuclear export is fully integrated into mRNA maturation. The coupling between mRNA maturation and nuclear export is an important mechanism for providing only fully functional and competent mRNA to the cytoplasmic translational machinery, thereby ensuring accuracy and swiftness of gene expression. This review describes the molecular mechanism of nuclear mRNA export mediated by the principal transport factors, including Tap-p15 and the TREX complex.
Collapse
|
21
|
Corradini BR, Iamashita P, Tampellini E, Farfel JM, Grinberg LT, Moreira-Filho CA. Complex network-driven view of genomic mechanisms underlying Parkinson's disease: analyses in dorsal motor vagal nucleus, locus coeruleus, and substantia nigra. BIOMED RESEARCH INTERNATIONAL 2014; 2014:543673. [PMID: 25525598 PMCID: PMC4261556 DOI: 10.1155/2014/543673] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/15/2014] [Indexed: 12/16/2022]
Abstract
Parkinson's disease (PD)—classically characterized by severe loss of dopaminergic neurons in the substantia nigra pars compacta—has a caudal-rostral progression, beginning in the dorsal motor vagal nucleus and, in a less extent, in the olfactory system, progressing to the midbrain and eventually to the basal forebrain and the neocortex. About 90% of the cases are idiopathic. To study the molecular mechanisms involved in idiopathic PD we conducted a comparative study of transcriptional interaction networks in the dorsal motor vagal nucleus (VA), locus coeruleus (LC), and substantia nigra (SN) of idiopathic PD in Braak stages 4-5 (PD) and disease-free controls (CT) using postmortem samples. Gene coexpression networks (GCNs) for each brain region (patients and controls) were obtained to identify highly connected relevant genes (hubs) and densely interconnected gene sets (modules). GCN analyses showed differences in topology and module composition between CT and PD networks for each anatomic region. In CT networks, VA, LC, and SN hub modules are predominantly associated with neuroprotection and homeostasis in the ageing brain, whereas in the patient's group, for the three brain regions, hub modules are mostly related to stress response and neuron survival/degeneration mechanisms.
Collapse
Affiliation(s)
- Beatriz Raposo Corradini
- Department of Pediatrics, Faculdade de Medicina da USP (FMUSP), Avenida Dr. Enéas Carvalho Aguiar 647, 5 Andar, 05403-900 São Paulo, SP, Brazil
| | - Priscila Iamashita
- Department of Pediatrics, Faculdade de Medicina da USP (FMUSP), Avenida Dr. Enéas Carvalho Aguiar 647, 5 Andar, 05403-900 São Paulo, SP, Brazil
| | - Edilaine Tampellini
- Brazilian Aging Brain Study Group (BEHEEC), LIM 22, FMUSP, 01246-903 São Paulo, SP, Brazil
- Hospital Israelita Albert Einstein, 05652-900 São Paulo, SP, Brazil
| | - José Marcelo Farfel
- Hospital Israelita Albert Einstein, 05652-900 São Paulo, SP, Brazil
- Division of Geriatrics, FMUSP, 01246-903 São Paulo, SP, Brazil
| | - Lea Tenenholz Grinberg
- Brazilian Aging Brain Study Group (BEHEEC), LIM 22, FMUSP, 01246-903 São Paulo, SP, Brazil
- Department of Pathology, FMUSP, 01246-903 São Paulo, SP, Brazil
- Department of Neurology and Pathology, University of California, San Francisco, CA 94143, USA
| | - Carlos Alberto Moreira-Filho
- Department of Pediatrics, Faculdade de Medicina da USP (FMUSP), Avenida Dr. Enéas Carvalho Aguiar 647, 5 Andar, 05403-900 São Paulo, SP, Brazil
| |
Collapse
|
22
|
Twyffels L, Gueydan C, Kruys V. Transportin-1 and Transportin-2: protein nuclear import and beyond. FEBS Lett 2014; 588:1857-68. [PMID: 24780099 DOI: 10.1016/j.febslet.2014.04.023] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 04/12/2014] [Accepted: 04/16/2014] [Indexed: 12/22/2022]
Abstract
Nearly 20 years after its identification as a new β-karyopherin mediating the nuclear import of the RNA-binding protein hnRNP A1, Transportin-1 is still commonly overlooked in comparison with its best known cousin, Importin-β. Transportin-1 is nonetheless a considerable player in nucleo-cytoplasmic transport. Over the past few years, significant progress has been made in the characterization of the nuclear localization signals (NLSs) that Transportin-1 recognizes, thereby providing the molecular basis of its diversified repertoire of cargoes. The recent discovery that mutations in the Transportin-dependent NLS of FUS cause mislocalization of this protein and result in amyotrophic lateral sclerosis illustrates the importance of Transportin-dependent import for human health. Besides, new functions of Transportin-1 are emerging in processes other than nuclear import. Here, we summarize what is known about Transportin-1 and the related β-karyopherin Transportin-2.
Collapse
Affiliation(s)
- Laure Twyffels
- Laboratoire de Biologie moléculaire du gène (CP300), Faculté des Sciences, Université Libre de Bruxelles (ULB), Belgium; Center for Microscopy and Molecular Imaging (CMMI), 6041 Gosselies, Belgium.
| | - Cyril Gueydan
- Laboratoire de Biologie moléculaire du gène (CP300), Faculté des Sciences, Université Libre de Bruxelles (ULB), Belgium
| | - Véronique Kruys
- Laboratoire de Biologie moléculaire du gène (CP300), Faculté des Sciences, Université Libre de Bruxelles (ULB), Belgium; Center for Microscopy and Molecular Imaging (CMMI), 6041 Gosselies, Belgium
| |
Collapse
|
23
|
Vanmarsenille L, Verbeeck J, Belet S, Roebroek AJ, Van de Putte T, Nevelsteen J, Callaerts-Vegh Z, D’Hooge R, Marynen P, Froyen G. Generation and characterization of an Nxf7 knockout mouse to study NXF5 deficiency in a patient with intellectual disability. PLoS One 2013; 8:e64144. [PMID: 23675524 PMCID: PMC3652825 DOI: 10.1371/journal.pone.0064144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/09/2013] [Indexed: 12/11/2022] Open
Abstract
Members of the Nuclear eXport Factor (NXF) family are involved in the export of mRNA from the nucleus to the cytoplasm, or hypothesized to play a role in transport of cytoplasmic mRNA. We previously reported on the loss of NXF5 in a male patient with a syndromic form of intellectual disability. To study the functional role of NXF5 we identified the mouse counterpart. Based on synteny, mouse Nxf2 is the ortholog of human NXF5. However, we provide several lines of evidence that mouse Nxf7 is the actual functional equivalent of NXF5. Both Nxf7 and NXF5 are predominantly expressed in the brain, show cytoplasmic localization, and present as granules in neuronal dendrites suggesting a role in cytoplasmic mRNA metabolism in neurons. Nxf7 was primarily detected in the pyramidal cells of the hippocampus and in layer V of the cortex. Similar to human NXF2, mouse Nxf2 is highly expressed in testis and shows a nuclear localization. Interestingly, these findings point to a different evolutionary path for both NXF genes in human and mouse. We thus generated and validated Nxf7 knockout mice, which were fertile and did not present any gross anatomical or morphological abnormalities. Expression profiling in the hippocampus and the cortex did not reveal significant changes between wild-type and Nxf7 knockout mice. However, impaired spatial memory was observed in these KO mice when evaluated in the Morris water maze test. In conclusion, our findings provide strong evidence that mouse Nxf7 is the functional counterpart of human NXF5, which might play a critical role in mRNA metabolism in the brain.
Collapse
Affiliation(s)
- Lieselot Vanmarsenille
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Jelle Verbeeck
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Stefanie Belet
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Anton J. Roebroek
- Experimental Mouse Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tom Van de Putte
- Laboratory of Molecular Biology (Celgen), Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Joke Nevelsteen
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | | | - Rudi D’Hooge
- Laboratory of Biological Psychology, KU Leuven, Leuven, Belgium
- Leuven Institute for Neuroscience and Disease (LIND), KU Leuven, Leuven, Belgium
| | - Peter Marynen
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Guy Froyen
- Human Genome Laboratory, VIB Center for the Biology of Disease, Leuven, Belgium
- Human Genome Laboratory, Department of Human Genetics, KU Leuven, Leuven, Belgium
- * E-mail:
| |
Collapse
|
24
|
The discovery and analysis of P Bodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:23-43. [PMID: 23224963 DOI: 10.1007/978-1-4614-5107-5_3] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
25
|
Reflections on ten years of history of, and future prospects for, GW182 and GW/P body research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 768:261-70. [PMID: 23224975 DOI: 10.1007/978-1-4614-5107-5_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
26
|
Mamon LA, Kliver SF, Golubkova EV. Evolutionarily conserved features of the retained intron in alternative transcripts of the <i>nxf1</i> (nuclear export factor) genes in different organisms. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojgen.2013.33018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
27
|
Goldie BJ, Cairns MJ. Post-transcriptional trafficking and regulation of neuronal gene expression. Mol Neurobiol 2011; 45:99-108. [PMID: 22167484 PMCID: PMC3259350 DOI: 10.1007/s12035-011-8222-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 11/22/2011] [Indexed: 11/24/2022]
Abstract
Intracellular messenger RNA (mRNA) traffic and translation must be highly regulated, both temporally and spatially, within eukaryotic cells to support the complex functional partitioning. This capacity is essential in neurons because it provides a mechanism for rapid input-restricted activity-dependent protein synthesis in individual dendritic spines. While this feature is thought to be important for synaptic plasticity, the structures and mechanisms that support this capability are largely unknown. Certainly specialized RNA binding proteins and binding elements in the 3′ untranslated region (UTR) of translationally regulated mRNA are important, but the subtlety and complexity of this system suggests that an intermediate “specificity” component is also involved. Small non-coding microRNA (miRNA) are essential for CNS development and may fulfill this role by acting as the guide strand for mediating complex patterns of post-transcriptional regulation. In this review we examine post-synaptic gene regulation, mRNA trafficking and the emerging role of post-transcriptional gene silencing in synaptic plasticity.
Collapse
Affiliation(s)
- Belinda J Goldie
- School of Biomedical Sciences and Pharmacy, Faculty of Health and the Hunter Medical Research Institute, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia
| | | |
Collapse
|
28
|
Zheng D, Chen CYA, Shyu AB. Unraveling regulation and new components of human P-bodies through a protein interaction framework and experimental validation. RNA (NEW YORK, N.Y.) 2011; 17:1619-34. [PMID: 21750099 PMCID: PMC3162328 DOI: 10.1261/rna.2789611] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The cellular factors involved in mRNA degradation and translation repression can aggregate into cytoplasmic domains known as GW bodies or mRNA processing bodies (P-bodies). However, current understanding of P-bodies, especially the regulatory aspect, remains relatively fragmentary. To provide a framework for studying the mechanisms and regulation of P-body formation, maintenance, and disassembly, we compiled a list of P-body proteins found in various species and further grouped both reported and predicted human P-body proteins according to their functions. By analyzing protein-protein interactions of human P-body components, we found that many P-body proteins form complex interaction networks with each other and with other cellular proteins that are not recognized as P-body components. The observation suggests that these other cellular proteins may play important roles in regulating P-body dynamics and functions. We further used siRNA-mediated gene knockdown and immunofluorescence microscopy to demonstrate the validity of our in silico analyses. Our combined approach identifies new P-body components and suggests that protein ubiquitination and protein phosphorylation involving 14-3-3 proteins may play critical roles for post-translational modifications of P-body components in regulating P-body dynamics. Our analyses provide not only a global view of human P-body components and their physical interactions but also a wealth of hypotheses to help guide future research on the regulation and function of human P-bodies.
Collapse
Affiliation(s)
- Dinghai Zheng
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School, Houston, Texas 77021, USA
| | - Chyi-Ying A. Chen
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School, Houston, Texas 77021, USA
| | - Ann-Bin Shyu
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School, Houston, Texas 77021, USA
- Corresponding author.E-mail .
| |
Collapse
|
29
|
Kurischko C, Kuravi VK, Herbert CJ, Luca FC. Nucleocytoplasmic shuttling of Ssd1 defines the destiny of its bound mRNAs. Mol Microbiol 2011; 81:831-49. [PMID: 21762218 DOI: 10.1111/j.1365-2958.2011.07731.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mechanisms that control mRNA metabolism are critical for cell function, development and stress response. The Saccharomyces cerevisiae mRNA-binding protein Ssd1 has been implicated in mRNA processing, ageing, stress response and maintenance of cell integrity. Ssd1 is a substrate of the LATS/NDR tumour suppressor orthologue Cbk1 kinase. Previous data indicate that Ssd1 localizes to the cytoplasm; however, biochemical interactions suggest that Ssd1 at least transiently localizes to the nucleus. We therefore explored whether nuclear localization is important for Ssd1 cytoplasmic functions. We identified a functional NLS in the N-terminal domain of Ssd1. An Ssd1-derived NLS-GFP fusion protein and several C-terminally truncated Ssd1 proteins, which presumably lack nuclear export sequences, accumulate in the nucleus. Alanine substitution of the Ssd1 NLS prevents Ssd1 nuclear entry, mRNA binding and disrupts Srl1 mRNA localization. Moreover, Ssd1-NLS mutations abolish Ssd1 toxicity in the absence of Cbk1 phosphorylation and cause Ssd1 to localize prominently to cytoplasmic puncta. These data indicate that nuclear shuttling is critical for Ssd1 mRNA binding and Ssd1-mRNA localization in the cytoplasm. Collectively these data support the model that Ssd1 functions analogously to hnRNPs, which bind mRNA co-transcriptionally, are exported to the cytoplasm and target mRNAs to sites of localized translation and P-bodies.
Collapse
Affiliation(s)
- Cornelia Kurischko
- Department of Animal Biology and Mari Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | | |
Collapse
|
30
|
Atsapkina AA, Golubkova EV, Kasatkina VV, Avanesyan EO, Ivankova NA, Mamon LA. Peculiarities of spermatogenesis in Drosophila melanogaster: Role of main transport receptor of mRNA (Dm NXF1). ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s1990519x10050044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
31
|
Abstract
P-bodies (processing bodies) are cytoplasmic foci visible by light microscopy in somatic cells of vertebrate and invertebrate origin as well as in yeast, plants and trypanosomes. At the molecular level, P-bodies are dynamic aggregates of specific mRNAs and proteins that serve a dual function: first, they harbour mRNAs that are translationally silenced, and such mRNA can exit again from P-bodies to re-engage in translation. Secondly, P-bodies recruit mRNAs that are targeted for deadenylation and degradation by the decapping/Xrn1 pathway. Whereas certain proteins are core constituents of P-bodies, others involved in recognizing short-lived mRNAs can only be trapped in P-bodies when mRNA decay is attenuated. This reflects the very transient interactions by which many proteins associate with P-bodies. In the present review, we summarize recent findings on the function, assembly and motility of P-bodies. An updated list of proteins and RNAs that localize to P-bodies will help in keeping track of this fast-growing field.
Collapse
|
32
|
Fujimura K, Katahira J, Kano F, Yoneda Y, Murata M. Microscopic dissection of the process of stress granule assembly. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1728-37. [DOI: 10.1016/j.bbamcr.2009.08.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 08/08/2009] [Accepted: 08/25/2009] [Indexed: 01/13/2023]
|
33
|
Kedersha N, Anderson P. Regulation of translation by stress granules and processing bodies. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 90:155-85. [PMID: 20374741 PMCID: PMC7102815 DOI: 10.1016/s1877-1173(09)90004-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Stress necessitates rapid reprogramming of translation in order to facilitate an adaptive response and promote survival. Cytoplasmic stress granules (SGs) and processing bodies (PBs) are dynamic structures that form in response to stress-induced translational arrest. PBs are linked to mRNA silencing and decay, while SGs are more closely linked to translation and the sorting of specific mRNAs for different fates. While they share some components and can interact physically, SGs and PBs are regulated independently, house separate functions, and contain unique markers. SG formation is associated with numerous disease states, and the expanding list of SG-associated proteins integrates SG formation with other processes such as transcription, splicing, and survival. Growing evidence suggests that SG assembly is initiated by translational arrest, and mediates cross talk with many other signaling pathways.
Collapse
Affiliation(s)
- Nancy Kedersha
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
34
|
Chang WL, Tarn WY. A role for transportin in deposition of TTP to cytoplasmic RNA granules and mRNA decay. Nucleic Acids Res 2009; 37:6600-12. [PMID: 19729507 PMCID: PMC2770677 DOI: 10.1093/nar/gkp717] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Importin-β family members, which shuttle between the nucleus and the cytoplasm, are essential for nucleocytoplasmic transport of macromolecules. We attempted to explore whether importin-β family proteins change their cellular localization in response to environmental change. In this report, we show that transportin (TRN) was minimally detected in cytoplasmic processing bodies (P-bodies) under normal cell conditions but largely translocated to stress granules (SGs) in stressed cells. Fluorescence recovery after photobleaching analysis indicated that TRN moves rapidly in and out of cytoplasmic granules. Depletion of TRN greatly enhanced P-body formation but did not affect the number or size of SGs, suggesting that TRN or its cargo(es) participates in cellular function of P-bodies. Accordingly, TRN associated with tristetraprolin (TTP) and its AU-rich element (ARE)-containing mRNA substrates. Depletion of TRN increased the number of P-bodies and stabilized ARE-containing mRNAs, as observed with knockdown of the 5′–3′ exonuclease Xrn1. Moreover, depletion of TRN retained TTP in P-bodies and meanwhile reduced the fraction of mobile TTP to SGs. Therefore, our data together suggest that TRN plays a role in trafficking of TTP between the cytoplasmic granules and whereby modulates the stability of ARE-containing mRNAs.
Collapse
Affiliation(s)
- Wei-Lun Chang
- Graduate Institute of Life Sciences, National Defense Medical Center and Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | | |
Collapse
|
35
|
Fujimura K, Katahira J, Kano F, Yoneda Y, Murata M. Selective localization of PCBP2 to cytoplasmic processing bodies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:878-87. [PMID: 19230839 DOI: 10.1016/j.bbamcr.2009.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 01/29/2009] [Accepted: 02/02/2009] [Indexed: 12/16/2022]
Abstract
Processing bodies (P-bodies) are cytoplasmic domains that have been implicated in critical steps of the regulation of gene expression, including mRNA decay and post-transcriptional gene silencing. Previously, we reported that PCBP2 (Poly-(rC) Binding Protein 2), a facilitator of IRES-mediated translation, is a novel P-body component. Interestingly, PCBP2 is recruited to only a subset of Dcp1a-positive P-bodies, which may reflect functional diversity among these structures. In this study, we examined the selective P-body localization of PCBP2 in detail. Co-localization studies between Dcp1a and PCBP2 revealed that PCBP2 is present in approximately 40% of P-bodies. While PCBP2 was more likely to reside in larger P-bodies, P-body size did not seem to be the sole determinant, and puromycin-induced enlargement of P-bodies only modestly increased the percentage of PCBP2-positive P-bodies. Photobleaching experiments demonstrated that the accumulation of PCBP2 to specific P-bodies is a dynamic process, which does not involve the protein's transcription-dependent nucleo-cytoplasmic shuttling activity. Finally, we found that PCBP1, a close relative of PCBP2, localizes to P-bodies in a similar manner to PCBP2. Taken together, these results establish the compositional diversity among P-bodies, and that PCBP2, probably in complex with other mRNP factors, may dynamically recognize such differences and accumulate to specific P-bodies.
Collapse
Affiliation(s)
- Ken Fujimura
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | | | | | | | | |
Collapse
|
36
|
Adaptor Aly and co-adaptor Thoc5 function in the Tap-p15-mediated nuclear export of HSP70 mRNA. EMBO J 2009; 28:556-67. [PMID: 19165146 DOI: 10.1038/emboj.2009.5] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Accepted: 01/05/2009] [Indexed: 11/08/2022] Open
Abstract
In metazoans, nuclear export of bulk mRNA is mediated by Tap-p15, a conserved heterodimeric export receptor that cooperates with adaptor RNA-binding proteins. In this article, we show that Thoc5, a subunit of the mammalian TREX complex, binds to a distinct surface on the middle (Ntf2-like) domain of Tap. Notably, adaptor protein Aly and Thoc5 can simultaneously bind to non-overlapping binding sites on Tap-p15. In vivo, Thoc5 was not required for bulk mRNA export. However, nuclear export of HSP70 mRNA depends on both Thoc5 and Aly. Consistent with a function as a specific export adaptor, Thoc5 exhibits in vitro RNA-binding activity and is associated with HSP70 mRNPs in vivo as a component of the stable THO complex. Thus, through the combinatorial use of an adaptor (e.g., Aly) and co-adapter (e.g., Thoc5), Tap-p15 could function as an export receptor for different classes of mRNAs.
Collapse
|