1
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Petrauskas A, Fortunati DL, Kandi AR, Pothapragada SS, Agrawal K, Singh A, Huelsmeier J, Hillebrand J, Brown G, Chaturvedi D, Lee J, Lim C, Auburger G, VijayRaghavan K, Ramaswami M, Bakthavachalu B. Structured and disordered regions of Ataxin-2 contribute differently to the specificity and efficiency of mRNP granule formation. PLoS Genet 2024; 20:e1011251. [PMID: 38768217 PMCID: PMC11166328 DOI: 10.1371/journal.pgen.1011251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 06/11/2024] [Accepted: 04/05/2024] [Indexed: 05/22/2024] Open
Abstract
Ataxin-2 (ATXN2) is a gene implicated in spinocerebellar ataxia type II (SCA2), amyotrophic lateral sclerosis (ALS) and Parkinsonism. The encoded protein is a therapeutic target for ALS and related conditions. ATXN2 (or Atx2 in insects) can function in translational activation, translational repression, mRNA stability and in the assembly of mRNP-granules, a process mediated by intrinsically disordered regions (IDRs). Previous work has shown that the LSm (Like-Sm) domain of Atx2, which can help stimulate mRNA translation, antagonizes mRNP-granule assembly. Here we advance these findings through a series of experiments on Drosophila and human Ataxin-2 proteins. Results of Targets of RNA Binding Proteins Identified by Editing (TRIBE), co-localization and immunoprecipitation experiments indicate that a polyA-binding protein (PABP) interacting, PAM2 motif of Ataxin-2 may be a major determinant of the mRNA and protein content of Ataxin-2 mRNP granules. Experiments with transgenic Drosophila indicate that while the Atx2-LSm domain may protect against neurodegeneration, structured PAM2- and unstructured IDR- interactions both support Atx2-induced cytotoxicity. Taken together, the data lead to a proposal for how Ataxin-2 interactions are remodelled during translational control and how structured and non-structured interactions contribute differently to the specificity and efficiency of RNP granule condensation as well as to neurodegeneration.
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Affiliation(s)
- Arnas Petrauskas
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Daniel L. Fortunati
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Arvind Reddy Kandi
- School of Biosciences and Bioengineering, Indian Institute of Technology, Mandi, India
| | | | - Khushboo Agrawal
- Tata Institute for Genetics and Society Centre at inStem, Bellary Road, Bangalore, India
- School of Biotechnology, Amrita Vishwa Vidyapeetham University, Kollam, Kerala, India
| | - Amanjot Singh
- National Centre for Biological Sciences, TIFR, Bangalore, India
- Manipal Institute of Regenerative Medicine, MAHE-Bengaluru, Govindapura, Bengaluru, India
| | - Joern Huelsmeier
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Jens Hillebrand
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Georgia Brown
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | | | - Jongbo Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, Republic of Korea
| | - Chunghun Lim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulsan, Republic of Korea
| | - Georg Auburger
- Experimental Neurology, Medical School, Goethe University, Frankfurt, Germany
| | | | - Mani Ramaswami
- Trinity College Institute of Neuroscience, School of Genetics and Microbiology, Smurfit Institute of Genetics and School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
- National Centre for Biological Sciences, TIFR, Bangalore, India
| | - Baskar Bakthavachalu
- School of Biosciences and Bioengineering, Indian Institute of Technology, Mandi, India
- Tata Institute for Genetics and Society Centre at inStem, Bellary Road, Bangalore, India
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2
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Apostolopoulos A, Kawamoto N, Chow SYA, Tsuiji H, Ikeuchi Y, Shichino Y, Iwasaki S. dCas13-mediated translational repression for accurate gene silencing in mammalian cells. Nat Commun 2024; 15:2205. [PMID: 38467613 PMCID: PMC10928199 DOI: 10.1038/s41467-024-46412-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 02/27/2024] [Indexed: 03/13/2024] Open
Abstract
Current gene silencing tools based on RNA interference (RNAi) or, more recently, clustered regularly interspaced short palindromic repeats (CRISPR)‒Cas13 systems have critical drawbacks, such as off-target effects (RNAi) or collateral mRNA cleavage (CRISPR‒Cas13). Thus, a more specific method of gene knockdown is needed. Here, we develop CRISPRδ, an approach for translational silencing, harnessing catalytically inactive Cas13 proteins (dCas13). Owing to its tight association with mRNA, dCas13 serves as a physical roadblock for scanning ribosomes during translation initiation and does not affect mRNA stability. Guide RNAs covering the start codon lead to the highest efficacy regardless of the translation initiation mechanism: cap-dependent, internal ribosome entry site (IRES)-dependent, or repeat-associated non-AUG (RAN) translation. Strikingly, genome-wide ribosome profiling reveals the ultrahigh gene silencing specificity of CRISPRδ. Moreover, the fusion of a translational repressor to dCas13 further improves the performance. Our method provides a framework for translational repression-based gene silencing in eukaryotes.
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Grants
- JP20H05784 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP21H05278 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP21H05734 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP23H04268 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP20H05786 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP23H02415 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP20K07016 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP23K05648 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP21K15023 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP23KJ2175 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- JP23gm6910005h0001 Japan Agency for Medical Research and Development (AMED)
- JP23gm6910005 Japan Agency for Medical Research and Development (AMED)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- Pioneering Projects MEXT | RIKEN
- Pioneering Projects MEXT | RIKEN
- Exploratory Research Center on Life and Living Systems (ExCELLS), 23EX601
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Affiliation(s)
- Antonios Apostolopoulos
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Naohiro Kawamoto
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Siu Yu A Chow
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hitomi Tsuiji
- Education and Research Division of Pharmacy, School of Pharmacy, Aichi Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Yoshiho Ikeuchi
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for AI and Beyond, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.
| | - Shintaro Iwasaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan.
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.
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3
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Nakashima M, Suga N, Ikeda Y, Yoshikawa S, Matsuda S. Circular RNAs, Noncoding RNAs, and N6-methyladenosine Involved in the Development of MAFLD. Noncoding RNA 2024; 10:11. [PMID: 38392966 PMCID: PMC10893449 DOI: 10.3390/ncrna10010011] [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: 12/08/2023] [Revised: 01/19/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
Noncoding RNAs (ncRNAs), including circular RNAs (circRNAs) and N6-methyladenosine (m6A), have been shown to play a critical role in the development of various diseases including obesity and metabolic disorder-associated fatty liver disease (MAFLD). Obesity is a chronic disease caused by excessive fat accumulation in the body, which has recently become more prevalent and is the foremost risk factor for MAFLD. Causes of obesity may involve the interaction of genetic, behavioral, and social factors. m6A RNA methylation might add a novel inspiration for understanding the development of obesity and MAFLD with post-transcriptional regulation of gene expression. In particular, circRNAs, microRNAs (miRNAs), and m6A might be implicated in the progression of MAFLD. Interestingly, m6A modification can modulate the translation, degradation, and other functions of ncRNAs. miRNAs/circRNAs can also modulate m6A modifications by affecting writers, erasers, and readers. In turn, ncRNAs could modulate the expression of m6A regulators in different ways. However, there is limited evidence on how these ncRNAs and m6A interact to affect the promotion of liver diseases. It seems that m6A can occur in DNA, RNA, and proteins that may be associated with several biological properties. This study provides a mechanistic understanding of the association of m6A modification and ncRNAs with liver diseases, especially for MAFLD. Comprehension of the association between m6A modification and ncRNAs may contribute to the development of treatment tactics for MAFLD.
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Affiliation(s)
| | | | | | | | - Satoru Matsuda
- Department of Food Science and Nutrition, Nara Women’s University, Kita-Uoya Nishimachi, Nara 630-8506, Japan
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Kamble VS, Pachpor TA, Khandagale SB, Wagh VV, Khare SP. Translation initiation and dysregulation of initiation factors in rare diseases. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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5
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Ma W, Wang X, Sun H, Xu B, Song R, Tian Y, Zhao L, Xu Y, Zhao Y, Yang F, Chen H, Gong R, Yu Y, Li X, Li S, Zhang W, Zhang T, Ne J, Cai B. Oxidant stress-sensitive circRNA Mdc1 controls cardiomyocyte chromosome stability and cell cycle re-entry during heart regeneration. Pharmacol Res 2022; 184:106422. [PMID: 36058431 DOI: 10.1016/j.phrs.2022.106422] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/18/2022] [Accepted: 08/30/2022] [Indexed: 11/29/2022]
Abstract
Targeting cardiomyocyte plasticity has emerged as a new strategy for promoting heart repair after myocardial infarction. However, the precise mechanistic network underlying heart regeneration is not completely understood. As noncoding RNAs, circular RNAs (circRNAs) play essential roles in regulating cardiac physiology and pathology. The present study aimed to investigate the potential roles of circMdc1 in cardiac repair after injury and elucidate its underlying mechanisms. Here, we identified that circMdc1 levels were upregulated in postnatal mouse hearts but downregulated in the regenerative myocardium. The expression of circMdc1 in cardiomyocytes is sensitive to oxidative stress, which was attenuated by N-acetyl-cysteine. Enforced circMdc1 expression inhibited cardiomyocyte proliferation, while circMdc1 silencing led to cardiomyocyte cell cycle re-entry. In vivo, the cardiac-specific adeno-associated virus-mediated knockdown of circMdc1 promoted cardiac regeneration and heart repair accompanied by improved heart function. Conversely, circMdc1 overexpression blunted the regenerative capacity of neonatal hearts after apex resection. Moreover, circMdc1 was able to block the translation of its host gene Mdc1 specifically by binding to PABP, affecting DNA damage and the chromosome stability of cardiomyocytes. Furthermore, overexpression of Mdc1 caused damaged mouse hearts to regenerate and repair after myocardial infarction in vivo. Oxidative stress-sensitive circMdc1 plays an important role in cardiac regeneration and heart repair after injury by regulating DNA damage and chromosome stability in cardiomyocytes by blocking the translation of the host gene Mdc1.
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Affiliation(s)
- Wenya Ma
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Xiuxiu Wang
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Hongyue Sun
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Binbin Xu
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Ruijie Song
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Yanan Tian
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Liang Zhao
- Department of Basic Medicine, Chengde Medical College, Chengde 067000, China
| | - Yan Xu
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Yiming Zhao
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Fan Yang
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Hongyang Chen
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Rui Gong
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Yang Yu
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Xingda Li
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Shuainan Li
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Wenwen Zhang
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Tingting Zhang
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Jingwen Ne
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China
| | - Benzhi Cai
- Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (The Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin 150086, China; Institute of Clinical Pharmacy, the Heilongjiang Key Laboratory of Drug Research, Harbin Medical University, Harbin 150086, China; Research Unit of Noninfectious Chronic Diseases in Frigid Zone, Chinese Academy of Medical Sciences, Harbin 150086, China.
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6
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Gu S, Jeon HM, Nam SW, Hong KY, Rahman MS, Lee JB, Kim Y, Jang SK. The flip-flop configuration of the PABP-dimer leads to switching of the translation function. Nucleic Acids Res 2021; 50:306-321. [PMID: 34904669 PMCID: PMC8754640 DOI: 10.1093/nar/gkab1205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/14/2022] Open
Abstract
Poly(A)-binding protein (PABP) is a translation initiation factor that interacts with the poly(A) tail of mRNAs. PABP bound to poly(A) stimulates translation by interacting with the eukaryotic initiation factor 4G (eIF4G), which brings the 3′ end of an mRNA close to its 5′ m7G cap structure through consecutive interactions of the 3′-poly(A)–PABP-eIF4G-eIF4E-5′ m7G cap. PABP is a highly abundant translation factor present in considerably larger quantities than mRNA and eIF4G in cells. However, it has not been elucidated how eIF4G, present in limited cellular concentrations, is not sequestered by mRNA-free PABP, present at high cellular concentrations, but associates with PABP complexed with the poly(A) tail of an mRNA. Here, we report that RNA-free PABPs dimerize with a head-to-head type configuration of PABP, which interferes in the interaction between PABP and eIF4G. We identified the domains of PABP responsible for PABP–PABP interaction. Poly(A) RNA was shown to convert the PABP–PABP complex into a poly(A)–PABP complex, with a head-to-tail-type configuration of PABP that facilitates the interaction between PABP and eIF4G. Lastly, we showed that the transition from the PABP dimer to the poly(A)–PABP complex is necessary for the translational activation function.
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Affiliation(s)
- Sohyun Gu
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Hyung-Min Jeon
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Seung Woo Nam
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Ka Young Hong
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Md Shafiqur Rahman
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Jong-Bong Lee
- School of Interdisciplinary Bioscience & Bioengineering, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea.,Department of Physices, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Youngjin Kim
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
| | - Sung Key Jang
- Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea.,School of Interdisciplinary Bioscience & Bioengineering, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Republic of Korea
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7
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A forward genetic screen identifies modifiers of rocaglate responsiveness. Sci Rep 2021; 11:18516. [PMID: 34531456 PMCID: PMC8445955 DOI: 10.1038/s41598-021-97765-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/27/2021] [Indexed: 12/13/2022] Open
Abstract
Rocaglates are a class of eukaryotic translation initiation inhibitors that are being explored as chemotherapeutic agents. They function by targeting eukaryotic initiation factor (eIF) 4A, an RNA helicase critical for recruitment of the 40S ribosome (and associated factors) to mRNA templates. Rocaglates perturb eIF4A activity by imparting a gain-of-function activity to eIF4A and mediating clamping to RNA. To appreciate how rocaglates could best be enabled in the clinic, an understanding of resistance mechanisms is important, as this could inform on strategies to bypass such events as well as identify responsive tumor types. Here, we report on the results of a positive selection, ORFeome screen aimed at identifying cDNAs capable of conferring resistance to rocaglates. Two of the most potent modifiers of rocaglate response identified were the transcription factors FOXP3 and NR1I3, both of which have been implicated in ABCB1 regulation-the gene encoding P-glycoprotein (Pgp). Pgp has previously been implicated in conferring resistance to silvestrol, a naturally occurring rocaglate, and we show here that this extends to additional synthetic rocaglate derivatives. In addition, FOXP3 and NR1I3 impart a multi-drug resistant phenotype that is reversed upon inhibition of Pgp, suggesting a potential therapeutic combination strategy.
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8
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Sanderson MR, Badior KE, Fahlman RP, Wevrick R. The necdin interactome: evaluating the effects of amino acid substitutions and cell stress using proximity-dependent biotinylation (BioID) and mass spectrometry. Hum Genet 2020; 139:1513-1529. [PMID: 32529326 DOI: 10.1007/s00439-020-02193-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/03/2020] [Indexed: 02/07/2023]
Abstract
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder caused by the loss of function of a set of imprinted genes on chromosome 15q11-15q13. One of these genes, NDN, encodes necdin, a protein that is important for neuronal differentiation and survival. Loss of Ndn in mice causes defects in the formation and function of the nervous system. Necdin is a member of the melanoma-associated antigen gene (MAGE) protein family. The functions of MAGE proteins depend highly on their interactions with other proteins, and in particular MAGE proteins interact with E3 ubiquitin ligases and deubiquitinases to form MAGE-RING E3 ligase-deubiquitinase complexes. Here, we used proximity-dependent biotin identification (BioID) and mass spectrometry (MS) to determine the network of protein-protein interactions (interactome) of the necdin protein. This process yielded novel as well as known necdin-proximate proteins that cluster into a protein network. Next, we used BioID-MS to define the interactomes of necdin proteins carrying coding variants. Variant necdin proteins had interactomes that were distinct from wildtype necdin. BioID-MS is not only a useful tool to identify protein-protein interactions, but also to analyze the effects of variants of unknown significance on the interactomes of proteins involved in genetic disease.
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Affiliation(s)
| | - Katherine E Badior
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton, AB, Canada
| | - Richard P Fahlman
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.,Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada.
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9
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Wu N, Yuan Z, Du KY, Fang L, Lyu J, Zhang C, He A, Eshaghi E, Zeng K, Ma J, Du WW, Yang BB. Translation of yes-associated protein (YAP) was antagonized by its circular RNA via suppressing the assembly of the translation initiation machinery. Cell Death Differ 2019; 26:2758-2773. [PMID: 31092884 PMCID: PMC7224378 DOI: 10.1038/s41418-019-0337-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/17/2019] [Accepted: 04/12/2019] [Indexed: 01/04/2023] Open
Abstract
Yap is the key component of Hippo pathway which plays crucial roles in tumorigenesis. Inhibition of Yap activity could promote apoptosis, suppress proliferation, and restrain metastasis of cancer cells. However, how Yap is regulated is not fully understood. Here, we reported Yap being negatively regulated by its circular RNA (circYap) through the suppression of the assembly of Yap translation initiation machinery. Overexpression of circYap in cancer cells significantly decreased Yap protein but did not affect its mRNA levels. As a consequence, it remarkably suppressed proliferation, migration and colony formation of the cells. We found that circYap could bind with Yap mRNA and the translation initiation associated proteins, eIF4G and PABP. The complex containing overexpressed circYap abolished the interaction of PABP on the poly(A) tail with eIF4G on the 5′-cap of the Yap mRNA, which functionally led to the suppression of Yap translation initiation. Individually blocking the binding sites of circYap on Yap mRNA or respectively mutating the binding sites for PABP and eIF4G derepressed Yap translation. Significantly, breast cancer tissue from patients in the study manifested dysregulation of circYap expression. Collectively, our study uncovered a novel molecular mechanism in the regulation of Yap and implicated a new function of circular RNA, supporting the pursuit of circYap as a potential tool for future cancer intervention.
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Affiliation(s)
- Nan Wu
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Zhidong Yuan
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,School of Basic Medicine, Gannan Medical University, Ganzhou, Jiangxi, China
| | - Kevin Y Du
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Ling Fang
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,China-Japan Union Hospital of Jilin University, Jilin, China
| | - Juanjuan Lyu
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Chao Zhang
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Alina He
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Esra Eshaghi
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Kaixuan Zeng
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Jian Ma
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - William W Du
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Burton B Yang
- Sunnybrook Research Institute, S-Wing Research Building, 2075 Bayview Ave, Toronto, M4N 3M5, Canada. .,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
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10
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Kachaev ZM, Lebedeva LA, Shaposhnikov AV, Moresco JJ, Yates JR, Schedl P, Shidlovskii YV. Paip2 cooperates with Cbp80 at an active promoter and participates in RNA Polymerase II phosphorylation in Drosophila. FEBS Lett 2019; 593:1102-1112. [PMID: 31001806 DOI: 10.1002/1873-3468.13391] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/28/2019] [Accepted: 04/09/2019] [Indexed: 01/01/2023]
Abstract
The Paip2 protein is a factor regulating mRNA translation and stability in the cytoplasm. It has also been found in the nuclei of several cell types in Drosophila. Here, we aim to elucidate the functions of Paip2 in the cell nucleus. We find that nuclear Paip2 is a component of an ~300-kDa protein complex. Paip2 interacts with mRNA capping factor and factors of RNA polymerase II (Pol II) transcription initiation and early elongation. Paip2 functionally cooperates with the Cbp80 subunit of the cap-binding complex, with both proteins ensuring proper Pol II C-terminal domain (CTD) Ser5 phosphorylation at the promoter. Thus, Paip2 is a novel player at the stage of mRNA capping and early Pol II elongation.
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Affiliation(s)
- Zaur M Kachaev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Lyubov A Lebedeva
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - James J Moresco
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Paul Schedl
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Yulii V Shidlovskii
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.,I.M. Sechenov First Moscow State Medical University, Russia
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11
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Ivanov A, Shuvalova E, Egorova T, Shuvalov A, Sokolova E, Bizyaev N, Shatsky I, Terenin I, Alkalaeva E. Polyadenylate-binding protein-interacting proteins PAIP1 and PAIP2 affect translation termination. J Biol Chem 2019; 294:8630-8639. [PMID: 30992367 DOI: 10.1074/jbc.ra118.006856] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 03/29/2019] [Indexed: 12/29/2022] Open
Abstract
Polyadenylate-binding protein (PABP) stimulates translation termination via interaction of its C-terminal domain with eukaryotic polypeptide chain release factor, eRF3. Additionally, two other proteins, poly(A)-binding protein-interacting proteins 1 and 2 (PAIP1 and PAIP2), bind the same domain of PABP and regulate its translation-related activity. To study the biochemistry of eRF3 and PAIP1/2 competition for PABP binding, we quantified the effects of PAIPs on translation termination in the presence or absence of PABP. Our results demonstrated that both PAIP1 and PAIP2 prevented translation termination at the premature termination codon, by controlling PABP activity. Moreover, PAIP1 and PAIP2 inhibited the activity of free PABP on translation termination in vitro However, after binding the poly(A) tail, PABP became insensitive to suppression by PAIPs and efficiently activated translation termination in the presence of eRF3a. Additionally, we revealed that PAIP1 binds eRF3 in solution, which stabilizes the post-termination complex. These results indicated that PAIP1 and PAIP2 participate in translation termination and are important regulators of readthrough at the premature termination codon.
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Affiliation(s)
- Alexandr Ivanov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia; Faculty of Bioengineering and Bioinformatics, M. V. Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ekaterina Shuvalova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Tatiana Egorova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Elizaveta Sokolova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Nikita Bizyaev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Ivan Shatsky
- Belozersky Institute of Physico-Chemical Biology, M. V. Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ilya Terenin
- Belozersky Institute of Physico-Chemical Biology, M. V. Lomonosov Moscow State University, Moscow 119234, Russia; Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Moscow 119146, Russia.
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia.
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12
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Tahmasebi S, Amiri M, Sonenberg N. Translational Control in Stem Cells. Front Genet 2019; 9:709. [PMID: 30697227 PMCID: PMC6341023 DOI: 10.3389/fgene.2018.00709] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/17/2018] [Indexed: 11/13/2022] Open
Abstract
Simultaneous measurements of mRNA and protein abundance and turnover in mammalian cells, have revealed that a significant portion of the cellular proteome is controlled by mRNA translation. Recent studies have demonstrated that both embryonic and somatic stem cells are dependent on low translation rates to maintain an undifferentiated state. Conversely, differentiation requires increased protein synthesis and failure to do so prevents differentiation. Notably, the low translation in stem cell populations is independent of the cell cycle, indicating that stem cells use unique strategies to decouple these fundamental cellular processes. In this chapter, we discuss different mechanisms used by stem cells to control translation, as well as the developmental consequences of translational deregulation.
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Affiliation(s)
- Soroush Tahmasebi
- Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, United States
| | - Mehdi Amiri
- Goodman Cancer Research Center, McGill University, Montreal, QC, Canada.,Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Nahum Sonenberg
- Goodman Cancer Research Center, McGill University, Montreal, QC, Canada.,Department of Biochemistry, McGill University, Montreal, QC, Canada
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13
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Dynamic interaction of poly(A)-binding protein with the ribosome. Sci Rep 2018; 8:17435. [PMID: 30487538 PMCID: PMC6261967 DOI: 10.1038/s41598-018-35753-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/09/2018] [Indexed: 01/15/2023] Open
Abstract
Eukaryotic mRNA has a cap structure and a poly(A) tail at the 5′ and 3′ ends, respectively. The cap structure is recognized by eIF (eukaryotic translation initiation factor) 4 F, while the poly(A) tail is bound by poly(A)-binding protein (PABP). PABP has four RNA recognition motifs (RRM1–4), and RRM1-2 binds both the poly(A) tail and eIF4G component of eIF4F, resulting in enhancement of translation. Here, we show that PABP interacts with the 40S and 60S ribosomal subunits dynamically via RRM2-3 or RRM3-4. Using a reconstituted protein expression system, we demonstrate that wild-type PABP activates translation in a dose-dependent manner, while a PABP mutant that binds poly(A) RNA and eIF4G, but not the ribosome, fails to do so. From these results, functional significance of the interaction of PABP with the ribosome is discussed.
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14
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Böhm BB, Fehrl Y, Janczi T, Schneider N, Burkhardt H. Cell adhesion-induced transient interaction of ADAM15 with poly(A) binding protein at the cell membrane colocalizes with mRNA translation. PLoS One 2018; 13:e0203847. [PMID: 30265671 PMCID: PMC6161846 DOI: 10.1371/journal.pone.0203847] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/28/2018] [Indexed: 12/15/2022] Open
Abstract
The regulation of temporo-spatial compartmentalization of protein synthesis is of crucial importance for a variety of physiologic cellular functions. Here, we demonstrate that the cell membrane-anchored disintegrin metalloproteinase ADAM15, upregulated in a variety of aggressively growing tumor cells, in the hyperproliferative synovial membrane of inflamed joints as well as in osteoarthritic chondrocytes, transiently binds to poly(A) binding protein 1 (PABP) in cells undergoing adhesion. The cytoplasmic domain of ADAM15 was shown to selectively interact with the proline-rich linker of PABP. Immunostainings of adhesion-triggered cells demonstrate an ADAM15-dependent recruitment of PABP to cell membrane foci coinciding with ongoing mRNA translation as visualized by the detection of puromycin-terminated polypeptides. Moreover, the increase in cell membrane-associated neosynthesis of puromycylated proteins upon induction of cell adhesion was proven linked to ADAM15 expression in HeLa and ADAM15-transfected chondrocytic cells. Thus, down regulation of ADAM15 by siRNA and/or the use of a cell line transfected with a mutant ADAM15-construct lacking the cytoplasmic tail resulted in a considerable reduction in the amount of cell membrane-associated puromycylated proteins formed during induced cell adhesion. These results provide first direct evidence for a regulatory role of ADAM15 on mRNA translation at the cell membrane that transiently emerges in response to triggering cell adhesion and might have potential implications under pathologic conditions of matrix remodeling associated with ADAM15 upregulation.
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Affiliation(s)
- Beate B. Böhm
- Division of Rheumatology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Yuliya Fehrl
- Division of Rheumatology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Tomasz Janczi
- Division of Rheumatology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Nadine Schneider
- Project Group Translational Medicine & Pharmacology TMP, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Frankfurt am Main, Germany
| | - Harald Burkhardt
- Division of Rheumatology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
- Project Group Translational Medicine & Pharmacology TMP, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Frankfurt am Main, Germany
- * E-mail:
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15
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Chen JH, Zhang RH, Lin SL, Li PF, Lan JJ, Song SS, Gao JM, Wang Y, Xie ZJ, Li FC, Jiang SJ. The Functional Role of the 3' Untranslated Region and Poly(A) Tail of Duck Hepatitis A Virus Type 1 in Viral Replication and Regulation of IRES-Mediated Translation. Front Microbiol 2018; 9:2250. [PMID: 30319572 PMCID: PMC6167517 DOI: 10.3389/fmicb.2018.02250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 09/04/2018] [Indexed: 01/04/2023] Open
Abstract
The duck hepatitis A virus type 1 (DHAV-1) is a member of Picornaviridae family, the genome of the virus contains a 5′ untranslated region (5′ UTR), a large open reading frame that encodes a polyprotein precursor and a 3′ UTR followed by a poly(A) tail. The translation initiation of virus proteins depends on the internal ribosome-entry site (IRES) element within the 5′ UTR. So far, little information is known about the role of the 3′ UTR and poly(A) tail during the virus proliferation. In this study, the function of the 3′ UTR and poly(A) tail of DHAV-1 in viral replication and IRES-mediated translation was investigated. The results showed that both 3′ UTR and poly(A) tail are important for maintaining viral genome RNA stability and viral genome replication. During DHAV-1 proliferation, at least 20 adenines were required for the optimal genome replication and the virus replication could be severely impaired when the poly (A) tail was curtailed to 10 adenines. In addition to facilitating viral genome replication, the presence of 3′ UTR and poly(A) tail significantly enhance IRES-mediated translation efficiency. Furthermore, 3′ UTR or poly(A) tail could function as an individual element to enhance the DHAV-1 IRES-mediated translation, during which process, the 3′ UTR exerts a greater initiation efficiency than the poly(A)25 tail.
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Affiliation(s)
- Jun-Hao Chen
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Rui-Hua Zhang
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Shao-Li Lin
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Peng-Fei Li
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Jing-Jing Lan
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Sha-Sha Song
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Ji-Ming Gao
- Department of Basic Medical Sciences, Taishan Medical College, Tai'an, China
| | - Yu Wang
- Department of Basic Medical Sciences, Taishan Medical College, Tai'an, China
| | - Zhi-Jing Xie
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
| | - Fu-Chang Li
- College of Animal Science and Technology, Shandong Agricultural University, Tai'an, China
| | - Shi-Jin Jiang
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an, China
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16
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Moore KS, Yagci N, van Alphen F, Meijer AB, ‘t Hoen PAC, von Lindern M. Strap associates with Csde1 and affects expression of select Csde1-bound transcripts. PLoS One 2018; 13:e0201690. [PMID: 30138317 PMCID: PMC6107111 DOI: 10.1371/journal.pone.0201690] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 07/22/2018] [Indexed: 02/06/2023] Open
Abstract
Erythropoiesis is regulated at many levels, including control of mRNA translation. Changing environmental conditions, such as hypoxia or the availability of nutrients and growth factors, require a rapid response enacted by the enhanced or repressed translation of existing transcripts. Cold shock domain protein e1 (Csde1/Unr) is an RNA-binding protein required for erythropoiesis and strongly upregulated in erythroblasts relative to other hematopoietic progenitors. The aim of this study is to identify the Csde1-containing protein complexes and investigate their role in post-transcriptional expression control of Csde1-bound transcripts. We show that Serine/Threonine kinase receptor-associated protein (Strap/Unrip), was the protein most strongly associated with Csde1 in erythroblasts. Strap is a WD40 protein involved in signaling and RNA splicing, but its role when associated with Csde1 is unknown. Reduced expression of Strap did not alter the pool of transcripts bound by Csde1. Instead, it altered the mRNA and/or protein expression of several Csde1-bound transcripts that encode for proteins essential for translational regulation during hypoxia, such as Hmbs, eIF4g3 and Pabpc4. Also affected by Strap knockdown were Vim, a Gata-1 target crucial for erythrocyte enucleation, and Elavl1, which stabilizes Gata-1 mRNA. The major cellular processes affected by both Csde1 and Strap were ribosome function and cell cycle control.
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Affiliation(s)
- Kat S. Moore
- Sanquin Research, Department of Hematopoiesis, and Landsteiner Laboratory Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Nurcan Yagci
- Sanquin Research, Department of Hematopoiesis, and Landsteiner Laboratory Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Floris van Alphen
- Sanquin Research, Department of Research Facilities, Amsterdam, The Netherlands
| | - Alexander B. Meijer
- Sanquin Research, Department of Research Facilities, Amsterdam, The Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Peter A. C. ‘t Hoen
- Centre for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marieke von Lindern
- Sanquin Research, Department of Hematopoiesis, and Landsteiner Laboratory Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
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17
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Kachaev ZM, Lebedeva LA, Kozlov EN, Toropygin IY, Schedl P, Shidlovskii YV. Paip2 is localized to active promoters and loaded onto nascent mRNA in Drosophila. Cell Cycle 2018; 17:1708-1720. [PMID: 29995569 DOI: 10.1080/15384101.2018.1496738] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Paip2 (Poly(A)-binding protein - interacting protein 2) is a conserved metazoan-specific protein that has been implicated in regulating the translation and stability of mRNAs. However, we have found that Paip2 is not restricted to the cytoplasm but is also found in the nucleus in Drosophila embryos, salivary glands, testes, and tissue culture cells. Nuclear Paip2 is associated with chromatin, and in chromatin immunoprecipitation experiments it maps to the promoter regions of active genes. However, this chromatin association is indirect, as it is RNA-dependent. Thus, Paip2 is one more item in the growing list of translation factors that are recruited to mRNAs co-transcriptionally.
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Affiliation(s)
- Zaur M Kachaev
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Lyubov A Lebedeva
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Eugene N Kozlov
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Ilya Y Toropygin
- d Center of Common Use "Human Proteome" , V.I. Orekhovich Research Institute of Biomedical Chemistry , Moscow , Russia
| | - Paul Schedl
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia.,b Department of Molecular Biology , Princeton University , Princeton , NJ , USA
| | - Yulii V Shidlovskii
- a Laboratory of Gene Expression Regulation in Development , Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia.,c Department of Biology and General Genetics , I.M. Sechenov First Moscow State Medical University , Moscow , Russia
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18
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Ozturk S, Uysal F. Potential roles of the poly(A)-binding proteins in translational regulation during spermatogenesis. J Reprod Dev 2018; 64:289-296. [PMID: 29780056 PMCID: PMC6105736 DOI: 10.1262/jrd.2018-026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Spermatogenesis is briefly defined as the production of mature spermatozoa from spermatogonial stem cells at the end of a strictly regulated process. It is well known that, to a large
extent, transcriptional activity ceases at mid-spermiogenesis. Several mRNAs transcribed during early stages of spermatogenesis are stored as ribonucleoproteins (RNPs). During the later
stages, translational control of these mRNAs is mainly carried out in a time dependent-manner by poly(A)-binding proteins (PABPs) in cooperation with other RNA-binding proteins and
translation-related factors. Conserved PABPs specifically bind to poly(A) tails at the 3′ ends of mRNAs to regulate their translational activity in spermatogenic cells. Studies in this field
have revealed that PABPs, particularly poly(A)-binding protein cytoplasmic 1 (Pabpc1), Pabpc2, and the embryonic poly(A)-binding protein (Epab), play roles in the translational regulation of
mRNAs required at later stages of spermatogenesis. In this review article, we evaluated the spatial and temporal expression patterns and potential functions of these PABPs in spermatogenic
cells during spermatogenesis. The probable relationship between alterations in PABP expression and the development of male infertility is also reviewed.
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Affiliation(s)
- Saffet Ozturk
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey
| | - Fatma Uysal
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey
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19
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Harvey RF, Smith TS, Mulroney T, Queiroz RML, Pizzinga M, Dezi V, Villenueva E, Ramakrishna M, Lilley KS, Willis AE. Trans-acting translational regulatory RNA binding proteins. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1465. [PMID: 29341429 PMCID: PMC5947564 DOI: 10.1002/wrna.1465] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/31/2017] [Accepted: 12/04/2017] [Indexed: 12/13/2022]
Abstract
The canonical molecular machinery required for global mRNA translation and its control has been well defined, with distinct sets of proteins involved in the processes of translation initiation, elongation and termination. Additionally, noncanonical, trans-acting regulatory RNA-binding proteins (RBPs) are necessary to provide mRNA-specific translation, and these interact with 5' and 3' untranslated regions and coding regions of mRNA to regulate ribosome recruitment and transit. Recently it has also been demonstrated that trans-acting ribosomal proteins direct the translation of specific mRNAs. Importantly, it has been shown that subsets of RBPs often work in concert, forming distinct regulatory complexes upon different cellular perturbation, creating an RBP combinatorial code, which through the translation of specific subsets of mRNAs, dictate cell fate. With the development of new methodologies, a plethora of novel RNA binding proteins have recently been identified, although the function of many of these proteins within mRNA translation is unknown. In this review we will discuss these methodologies and their shortcomings when applied to the study of translation, which need to be addressed to enable a better understanding of trans-acting translational regulatory proteins. Moreover, we discuss the protein domains that are responsible for RNA binding as well as the RNA motifs to which they bind, and the role of trans-acting ribosomal proteins in directing the translation of specific mRNAs. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes Translation > Translation Regulation Translation > Translation Mechanisms.
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Affiliation(s)
| | - Tom S. Smith
- Cambridge Centre for Proteomics, Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | - Rayner M. L. Queiroz
- Cambridge Centre for Proteomics, Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | | | - Eneko Villenueva
- Cambridge Centre for Proteomics, Department of BiochemistryUniversity of CambridgeCambridgeUK
| | | | - Kathryn S. Lilley
- Cambridge Centre for Proteomics, Department of BiochemistryUniversity of CambridgeCambridgeUK
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20
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Fukao A, Fujiwara T. The coupled and uncoupled mechanisms by which trans-acting factors regulate mRNA stability and translation. J Biochem 2017; 161:309-314. [PMID: 28039391 DOI: 10.1093/jb/mvw086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/11/2016] [Indexed: 12/25/2022] Open
Abstract
In mammals, spatiotemporal control of protein synthesis plays a key role in the post-transcriptional regulation of gene expression during cell proliferation, development and differentiation and RNA-binding proteins (RBPs) and microRNAs (miRNAs) are required for this phenomenon. RBPs and miRNAs control the levels of mRNA protein products by regulating mRNA stability and translation. Recent studies have shown that RBPs and miRNAs simultaneously regulate mRNA stability and translation, and that the differential functions of RBPs and miRNAs are dependent on their interaction partners. Here, we summarize the coupled- and uncoupled mechanisms by which trans-acting factors regulate mRNA stability and translation.
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21
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Bukhari SIA, Vasudevan S. FXR1a-associated microRNP: A driver of specialized non-canonical translation in quiescent conditions. RNA Biol 2016; 14:137-145. [PMID: 27911187 DOI: 10.1080/15476286.2016.1265197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Eukaryotic protein synthesis is a multifaceted process that requires coordination of a set of translation factors in a particular cellular state. During normal growth and proliferation, cells generally make their proteome via conventional translation that utilizes canonical translation factors. When faced with environmental stress such as growth factor deprivation, or in response to biological cues such as developmental signals, cells can reduce canonical translation. In this situation, cells adapt alternative modes of translation to make specific proteins necessary for required biological functions under these distinct conditions. To date, a number of alternative translation mechanisms have been reported, which include non-canonical, cap dependent translation and cap independent translation such as IRES mediated translation. Here, we discuss one of the alternative modes of translation mediated by a specialized microRNA complex, FXR1a-microRNP that promotes non-canonical, cap dependent translation in quiescent conditions, where canonical translation is reduced due to low mTOR activity.
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Affiliation(s)
- Syed I A Bukhari
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - Shobha Vasudevan
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
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22
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Ivanov A, Mikhailova T, Eliseev B, Yeramala L, Sokolova E, Susorov D, Shuvalov A, Schaffitzel C, Alkalaeva E. PABP enhances release factor recruitment and stop codon recognition during translation termination. Nucleic Acids Res 2016; 44:7766-76. [PMID: 27418677 PMCID: PMC5027505 DOI: 10.1093/nar/gkw635] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 07/01/2016] [Indexed: 01/01/2023] Open
Abstract
Poly(A)-binding protein (PABP) is a major component of the messenger RNA–protein complex. PABP is able to bind the poly(A) tail of mRNA, as well as translation initiation factor 4G and eukaryotic release factor 3a (eRF3a). PABP has been found to stimulate translation initiation and to inhibit nonsense-mediated mRNA decay. Using a reconstituted mammalian in vitro translation system, we show that PABP directly stimulates translation termination. PABP increases the efficiency of translation termination by recruitment of eRF3a and eRF1 to the ribosome. PABP's function in translation termination depends on its C-terminal domain and its interaction with the N-terminus of eRF3a. Interestingly, we discover that full-length eRF3a exerts a different mode of function compared to its truncated form eRF3c, which lacks the N-terminal domain. Pre-association of eRF3a, but not of eRF3c, with pre-termination complexes (preTCs) significantly increases the efficiency of peptidyl–tRNA hydrolysis by eRF1. This implicates new, additional interactions of full-length eRF3a with the ribosomal preTC. Based on our findings, we suggest that PABP enhances the productive binding of the eRF1–eRF3 complex to the ribosome, via interactions with the N-terminal domain of eRF3a which itself has an active role in translation termination.
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Affiliation(s)
- Alexandr Ivanov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia Faculty of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Tatyana Mikhailova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Boris Eliseev
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, 38042 Grenoble, France
| | - Lahari Yeramala
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, 38042 Grenoble, France
| | - Elizaveta Sokolova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Denis Susorov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia Faculty of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Christiane Schaffitzel
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, 38042 Grenoble, France School of Biochemistry, University of Bristol, BS8 1TD, UK
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
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23
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Flamand MN, Wu E, Vashisht A, Jannot G, Keiper BD, Simard MJ, Wohlschlegel J, Duchaine TF. Poly(A)-binding proteins are required for microRNA-mediated silencing and to promote target deadenylation in C. elegans. Nucleic Acids Res 2016; 44:5924-35. [PMID: 27095199 PMCID: PMC4937315 DOI: 10.1093/nar/gkw276] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 01/08/2023] Open
Abstract
Cytoplasmic poly(A)-binding proteins (PABPs) link mRNA 3' termini to translation initiation factors, but they also play key roles in mRNA regulation and decay. Reports from mice, zebrafish and Drosophila further involved PABPs in microRNA (miRNA)-mediated silencing, but through seemingly distinct mechanisms. Here, we implicate the two Caenorhabditis elegans PABPs (PAB-1 and PAB-2) in miRNA-mediated silencing, and elucidate their mechanisms of action using concerted genetics, protein interaction analyses, and cell-free assays. We find that C. elegans PABPs are required for miRNA-mediated silencing in embryonic and larval developmental stages, where they act through a multi-faceted mechanism. Depletion of PAB-1 and PAB-2 results in loss of both poly(A)-dependent and -independent translational silencing. PABPs accelerate miRNA-mediated deadenylation, but this contribution can be modulated by 3'UTR sequences. While greater distances with the poly(A) tail exacerbate dependency on PABP for deadenylation, more potent miRNA-binding sites partially suppress this effect. Our results refine the roles of PABPs in miRNA-mediated silencing and support a model wherein they enable miRNA-binding sites by looping the 3'UTR poly(A) tail to the bound miRISC and deadenylase.
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Affiliation(s)
- Mathieu N Flamand
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada Goodman Cancer Research Center, McGill University, Montreal, QC H3A 1A3, Canada
| | - Edlyn Wu
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada Division of Experimental Medicine & Goodman Cancer Research Center, McGill University, Montreal, QC H3A 1A3, Canada
| | - Ajay Vashisht
- Department of Biological Chemistry David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Guillaume Jannot
- St-Patrick Research Group in Basic Oncology, Centre Hospitalier Universitaire de Québec-Université Laval (Hôtel-Dieu de Québec), Laval University Cancer Research Centre, Quebec City, QC G1R 2J6, Canada
| | - Brett D Keiper
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
| | - Martin J Simard
- St-Patrick Research Group in Basic Oncology, Centre Hospitalier Universitaire de Québec-Université Laval (Hôtel-Dieu de Québec), Laval University Cancer Research Centre, Quebec City, QC G1R 2J6, Canada
| | - James Wohlschlegel
- Department of Biological Chemistry David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Thomas F Duchaine
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada Division of Experimental Medicine & Goodman Cancer Research Center, McGill University, Montreal, QC H3A 1A3, Canada
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24
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The molecular choreography of protein synthesis: translational control, regulation, and pathways. Q Rev Biophys 2016; 49:e11. [PMID: 27658712 DOI: 10.1017/s0033583516000056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Translation of proteins by the ribosome regulates gene expression, with recent results underscoring the importance of translational control. Misregulation of translation underlies many diseases, including cancer and many genetic diseases. Decades of biochemical and structural studies have delineated many of the mechanistic details in prokaryotic translation, and sketched the outlines of eukaryotic translation. However, translation may not proceed linearly through a single mechanistic pathway, but likely involves multiple pathways and branchpoints. The stochastic nature of biological processes would allow different pathways to occur during translation that are biased by the interaction of the ribosome with other translation factors, with many of the steps kinetically controlled. These multiple pathways and branchpoints are potential regulatory nexus, allowing gene expression to be tuned at the translational level. As research focus shifts toward eukaryotic translation, certain themes will be echoed from studies on prokaryotic translation. This review provides a general overview of the dynamic data related to prokaryotic and eukaryotic translation, in particular recent findings with single-molecule methods, complemented by biochemical, kinetic, and structural findings. We will underscore the importance of viewing the process through the viewpoints of regulation, translational control, and heterogeneous pathways.
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25
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Sutherland JM, Siddall NA, Hime GR, McLaughlin EA. RNA binding proteins in spermatogenesis: an in depth focus on the Musashi family. Asian J Androl 2016; 17:529-36. [PMID: 25851660 PMCID: PMC4492041 DOI: 10.4103/1008-682x.151397] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Controlled gene regulation during gamete development is vital for maintaining reproductive potential. During the complex process of mammalian spermatogenesis, male germ cells experience extended periods of the inactive transcription despite heavy translational requirements for continued growth and differentiation. Hence, spermatogenesis is highly reliant on mechanisms of posttranscriptional regulation of gene expression, facilitated by RNA binding proteins (RBPs), which remain abundantly expressed throughout this process. One such group of proteins is the Musashi family, previously identified as critical regulators of testis germ cell development and meiosis in Drosophila, and also shown to be vital to sperm development and reproductive potential in the mouse. This review describes the role and function of RBPs within the scope of male germ cell development, focusing on our recent knowledge of the Musashi proteins in spermatogenesis. The functional mechanisms utilized by RBPs within the cell are outlined in depth, and the significance of sub-cellular localization and stage-specific expression in relation to the mode and impact of posttranscriptional regulation is also highlighted. We emphasize the historical role of the Musashi family of RBPs in stem cell function and cell fate determination, as originally characterized in Drosophila and Xenopus, and conclude with our current understanding of the differential roles and functions of the mammalian Musashi proteins, Musashi-1 and Musashi-2, with a primary focus on our findings in spermatogenesis. This review highlights both the essential contribution of RBPs to posttranscriptional regulation and the importance of the Musashi family as master regulators of male gamete development.
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Affiliation(s)
| | | | | | - Eileen A McLaughlin
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
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26
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Yoshikawa T, Wu J, Otsuka M, Kishikawa T, Ohno M, Shibata C, Takata A, Han F, Kang YJ, Chen CYA, Shyu AB, Han J, Koike K. ROCK inhibition enhances microRNA function by promoting deadenylation of targeted mRNAs via increasing PAIP2 expression. Nucleic Acids Res 2015; 43:7577-89. [PMID: 26187994 PMCID: PMC4551943 DOI: 10.1093/nar/gkv728] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 07/03/2015] [Indexed: 12/11/2022] Open
Abstract
The reduced expression levels and functional impairment of global miRNAs are related to various human diseases, including cancers. However, relatively little is known about how global miRNA function may be upregulated. Here, we report that global miRNA function can be enhanced by Rho-associated, coiled-coil-containing protein kinase (ROCK) inhibitors. The regulation of miRNA function by ROCK inhibitors is mediated, at least in part, by poly(A)-binding protein-interacting protein 2 (PAIP2), which enhances poly(A)-shortening of miRNA-targeted mRNAs and leads to global upregulation of miRNA function. In the presence of a ROCK inhibitor, PAIP2 expression is enhanced by the transcription factor hepatocyte nuclear factor 4 alpha (HNF4A) through increased ROCK1 nuclear localization and enhanced ROCK1 association with HNF4A. Our data reveal an unexpected role of ROCK1 as a cofactor of HNF4A in enhancing PAIP2 transcription. ROCK inhibitors may be useful for the various pathologies associated with the impairment of global miRNA function.
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Affiliation(s)
- Takeshi Yoshikawa
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Jianfeng Wu
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Motoyuki Otsuka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama 332-0012, Japan
| | - Takahiro Kishikawa
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Motoko Ohno
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Chikako Shibata
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Akemi Takata
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Felicia Han
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Young Jun Kang
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Chyi-Ying A Chen
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School, Houston, TX, USA
| | - Ann-Bin Shyu
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School, Houston, TX, USA
| | - Jiahuai Han
- State Key Laboratory of Cellular Stress Biology and School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
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27
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Buffington SA, Huang W, Costa-Mattioli M. Translational control in synaptic plasticity and cognitive dysfunction. Annu Rev Neurosci 2015; 37:17-38. [PMID: 25032491 DOI: 10.1146/annurev-neuro-071013-014100] [Citation(s) in RCA: 251] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Activity-dependent changes in the strength of synaptic connections are fundamental to the formation and maintenance of memory. The mechanisms underlying persistent changes in synaptic strength in the hippocampus, specifically long-term potentiation and depression, depend on new protein synthesis. Such changes are thought to be orchestrated by engaging the signaling pathways that regulate mRNA translation in neurons. In this review, we discuss the key regulatory pathways that govern translational control in response to synaptic activity and the mRNA populations that are specifically targeted by these pathways. The critical contribution of regulatory control over new protein synthesis to proper cognitive function is underscored by human disorders associated with either silencing or mutation of genes encoding proteins that directly regulate translation. In light of these clinical implications, we also consider the therapeutic potential of targeting dysregulated translational control to treat cognitive disorders of synaptic dysfunction.
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Affiliation(s)
- Shelly A Buffington
- Department of Neuroscience, Memory and Brain Research Center, Baylor College of Medicine, Houston, Texas 77030; , ,
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28
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Hauser B, Zhao Y, Pang X, Ling Z, Myers E, Wang P, Califano J, Gu X. Functions of MiRNA-128 on the regulation of head and neck squamous cell carcinoma growth and apoptosis. PLoS One 2015; 10:e0116321. [PMID: 25764126 PMCID: PMC4357443 DOI: 10.1371/journal.pone.0116321] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 12/08/2014] [Indexed: 02/06/2023] Open
Abstract
Background Incidence of head and neck squamous cell carcinoma (HNSCC) has continuously increased in past years while its survival rate has not been significantly improved. There is a critical need to better understand the genetic regulation of HNSCC tumorigenesis and progression. In this study, we comprehensively analyzed the function of miRNA-128 (miR-128) in the regulation of HNSCC growth and its putative targets in vitro and in vivo systems. Methods The function and targets of miR-128 were investigated in human HNSCC cell lines (JHU-13 and JHU-22), which were stably transfected with the miR-128 gene using a lentiviral delivery system. The expression levels of miR-128 and its targeted proteins were analyzed with qRT-PCR, Western blotting and flow cytometry. The binding capacity of miRNA-128 to its putative targets was determined using a luciferase report assay. MTT, colony formation, and a tumor xenograft model further evaluated the effects of miR-128 on HNSCC growth. Results We generated two miR-128 stably transfected human HNSCC cell lines (JHU-13miR-128 and JHU-22miR-128). Enforced expression of miR-128 was detected in both cultured JHU-13miR-128 and JHU-22miR-128 cell lines, approximately seventeen to twenty folds higher than in vector control cell lines. miRNA-128 was able to bind with the 3′-untranslated regions of BMI-1, BAG-2, BAX, H3f3b, and Paip2 mRNAs, resulting in significant reduction of the targeted protein levels. We found that upregulated miR-128 expression significantly inhibited both JHU-13miR-128 and JHU-22miR-128 cell viability approximately 20 to 40%, and the JHU-22miR-128 tumor xenograft growth compared to the vector control groups. Conclusions miR-128 acted as a tumor suppressor inhibiting the HNSCC growth by directly mediating the expression of putative targets. Our results provide a better understanding of miRNA-128 function and its potential targets, which may be valuable for developing novel diagnostic markers and targeted therapy.
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Affiliation(s)
- Belinda Hauser
- Department of Genetics and Human Genetics, Howard University, Washington, DC, United States of America
| | - Yuan Zhao
- Department of Oral Pathology, Howard University, Washington DC, United States of America
| | - Xiaowu Pang
- Department of Oral Pathology, Howard University, Washington DC, United States of America
| | | | - Ernest Myers
- Department of Otolaryngology-Head and Neck Surgery, Howard University, Washington, DC, United States of America
| | - Paul Wang
- Department of Radiology, Howard University, Washington DC, United States of America
- Cancer Center, Howard University, Washington, District of Columbia, United States of America
| | - Joseph Califano
- Departments of Otolaryngology-Head and Neck Surgery, and Head & Neck Research Division, Johns Hopkins University, Baltimore, Maryland, United states of America
| | - Xinbin Gu
- Department of Genetics and Human Genetics, Howard University, Washington, DC, United States of America
- Department of Oral Pathology, Howard University, Washington DC, United States of America
- Cancer Center, Howard University, Washington, District of Columbia, United States of America
- * E-mail:
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29
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Wilczynska A, Bushell M. The complexity of miRNA-mediated repression. Cell Death Differ 2014; 22:22-33. [PMID: 25190144 DOI: 10.1038/cdd.2014.112] [Citation(s) in RCA: 322] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 06/10/2014] [Accepted: 06/25/2014] [Indexed: 01/01/2023] Open
Abstract
Since their discovery 20 years ago, miRNAs have attracted much attention from all areas of biology. These short (∼22 nt) non-coding RNA molecules are highly conserved in evolution and are present in nearly all eukaryotes. They have critical roles in virtually every cellular process, particularly determination of cell fate in development and regulation of the cell cycle. Although it has long been known that miRNAs bind to mRNAs to trigger translational repression and degradation, there had been much debate regarding their precise mode of action. It is now believed that translational control is the primary event, only later followed by mRNA destabilisation. This review will discuss the most recent advances in our understanding of the molecular underpinnings of miRNA-mediated repression. Moreover, we highlight the multitude of regulatory mechanisms that modulate miRNA function.
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Affiliation(s)
- A Wilczynska
- MRC Toxicology Unit, University of Leicester, Leicester, UK
| | - M Bushell
- MRC Toxicology Unit, University of Leicester, Leicester, UK
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30
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Fehler O, Singh P, Haas A, Ulrich D, Müller JP, Ohnheiser J, Klempnauer KH. An evolutionarily conserved interaction of tumor suppressor protein Pdcd4 with the poly(A)-binding protein contributes to translation suppression by Pdcd4. Nucleic Acids Res 2014; 42:11107-18. [PMID: 25190455 PMCID: PMC4176178 DOI: 10.1093/nar/gku800] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The tumor suppressor protein programmed cell death 4 (Pdcd4) has been implicated in the translational regulation of specific mRNAs, however, the identities of the natural Pdcd4 target mRNAs and the mechanisms by which Pdcd4 affects their translation are not well understood. Pdcd4 binds to the eukaryotic translation initiation factor eIF4A and inhibits its helicase activity, which has suggested that Pdcd4 suppresses translation initiation of mRNAs containing structured 5′-untranslated regions. Recent work has revealed a second inhibitory mechanism, which is eIF4A-independent and involves direct RNA-binding of Pdcd4 to the target mRNAs. We have now identified the poly(A)-binding protein (PABP) as a novel direct interaction partner of Pdcd4. The ability to interact with PABP is shared between human and Drosophila Pdcd4, indicating that it has been highly conserved during evolution. Mutants of Pdcd4 that have lost the ability to interact with PABP fail to stably associate with ribosomal complexes in sucrose density gradients and to suppress translation, as exemplified by c-myb mRNA. Overall, our work identifies PABP as a novel functionally relevant Pdcd4 interaction partner that contributes to the regulation of translation by Pdcd4.
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Affiliation(s)
- Olesja Fehler
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Priyanka Singh
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Astrid Haas
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Diana Ulrich
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Jan P Müller
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Johanna Ohnheiser
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Karl-Heinz Klempnauer
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
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31
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Joncourt R, Eberle AB, Rufener SC, Mühlemann O. Eukaryotic initiation factor 4G suppresses nonsense-mediated mRNA decay by two genetically separable mechanisms. PLoS One 2014; 9:e104391. [PMID: 25148142 PMCID: PMC4141738 DOI: 10.1371/journal.pone.0104391] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 07/08/2014] [Indexed: 11/19/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD), which is best known for degrading mRNAs with premature termination codons (PTCs), is thought to be triggered by aberrant translation termination at stop codons located in an environment of the mRNP that is devoid of signals necessary for proper termination. In mammals, the cytoplasmic poly(A)-binding protein 1 (PABPC1) has been reported to promote correct termination and therewith antagonize NMD by interacting with the eukaryotic release factors 1 (eRF1) and 3 (eRF3). Using tethering assays in which proteins of interest are recruited as MS2 fusions to a NMD reporter transcript, we show that the three N-terminal RNA recognition motifs (RRMs) of PABPC1 are sufficient to antagonize NMD, while the eRF3-interacting C-terminal domain is dispensable. The RRM1-3 portion of PABPC1 interacts with eukaryotic initiation factor 4G (eIF4G) and tethering of eIF4G to the NMD reporter also suppresses NMD. We identified the interactions of the eIF4G N-terminus with PABPC1 and the eIF4G core domain with eIF3 as two genetically separable features that independently enable tethered eIF4G to inhibit NMD. Collectively, our results reveal a function of PABPC1, eIF4G and eIF3 in translation termination and NMD suppression, and they provide additional evidence for a tight coupling between translation termination and initiation.
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Affiliation(s)
- Raphael Joncourt
- University of Bern, Department of Chemistry and Biochemistry, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Andrea B. Eberle
- University of Bern, Department of Chemistry and Biochemistry, Bern, Switzerland
| | - Simone C. Rufener
- University of Bern, Department of Chemistry and Biochemistry, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Oliver Mühlemann
- University of Bern, Department of Chemistry and Biochemistry, Bern, Switzerland
- * E-mail:
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The "tale" of poly(A) binding protein: the MLLE domain and PAM2-containing proteins. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:1062-8. [PMID: 25120199 DOI: 10.1016/j.bbagrm.2014.08.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/11/2014] [Accepted: 08/04/2014] [Indexed: 11/21/2022]
Abstract
The cytoplasmic poly(A) binding protein 1 (PABPC1) is an essential eukaryotic translational initiation factor first described over 40 years ago. Most studies of PABPC1 have focused on its N-terminal RRM domains, which bind the mRNA 3' poly(A) tail and 5' translation complex eIF4F via eIF4G; however, the protein also contains a C-terminal MLLE domain that binds a peptide motif, termed PAM2, found in many proteins involved in translation regulation and mRNA metabolism. Studies over the past decade have revealed additional functions of PAM2-containing proteins (PACs) in neurodegenerative diseases, circadian rhythms, innate defense, and ubiquitin-mediated protein degradation. Here, we summarize functional and structural studies of the MLLE/PAM2 interaction and discuss the diverse roles of PACs.
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Weidmann CA, Raynard NA, Blewett NH, Van Etten J, Goldstrohm AC. The RNA binding domain of Pumilio antagonizes poly-adenosine binding protein and accelerates deadenylation. RNA (NEW YORK, N.Y.) 2014; 20:1298-319. [PMID: 24942623 PMCID: PMC4105754 DOI: 10.1261/rna.046029.114] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 05/20/2014] [Indexed: 05/24/2023]
Abstract
PUF proteins are potent repressors that serve important roles in stem cell maintenance, neurological processes, and embryonic development. These functions are driven by PUF protein recognition of specific binding sites within the 3' untranslated regions of target mRNAs. In this study, we investigated mechanisms of repression by the founding PUF, Drosophila Pumilio, and its human orthologs. Here, we evaluated a previously proposed model wherein the Pumilio RNA binding domain (RBD) binds Argonaute, which in turn blocks the translational activity of the eukaryotic elongation factor 1A. Surprisingly, we found that Argonautes are not necessary for repression elicited by Drosophila and human PUFs in vivo. A second model proposed that the RBD of Pumilio represses by recruiting deadenylases to shorten the mRNA's polyadenosine tail. Indeed, the RBD binds to the Pop2 deadenylase and accelerates deadenylation; however, this activity is not crucial for regulation. Rather, we determined that the poly(A) is necessary for repression by the RBD. Our results reveal that poly(A)-dependent repression by the RBD requires the poly(A) binding protein, pAbp. Furthermore, we show that repression by the human PUM2 RBD requires the pAbp ortholog, PABPC1. Pumilio associates with pAbp but does not disrupt binding of pAbp to the mRNA. Taken together, our data support a model wherein the Pumilio RBD antagonizes the ability of pAbp to promote translation. Thus, the conserved function of the PUF RBD is to bind specific mRNAs, antagonize pAbp function, and promote deadenylation.
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Affiliation(s)
- Chase A Weidmann
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA Genetics Training Program, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Nathan A Raynard
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA Genetics Training Program, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Nathan H Blewett
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Jamie Van Etten
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Aaron C Goldstrohm
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA Genetics Training Program, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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Lee SH, Oh J, Park J, Paek KY, Rho S, Jang SK, Lee JB. Poly(A) RNA and Paip2 act as allosteric regulators of poly(A)-binding protein. Nucleic Acids Res 2013; 42:2697-707. [PMID: 24293655 PMCID: PMC3936760 DOI: 10.1093/nar/gkt1170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
When bound to the 3′ poly(A) tail of mRNA, poly(A)-binding protein (PABP) modulates mRNA translation and stability through its association with various proteins. By visualizing individual PABP molecules in real time, we found that PABP, containing four RNA recognition motifs (RRMs), adopts a conformation on poly(A) binding in which RRM1 is in proximity to RRM4. This conformational change is due to the bending of the region between RRM2 and RRM3. PABP-interacting protein 2 actively disrupts the bent structure of PABP to the extended structure, resulting in the inhibition of PABP-poly(A) binding. These results suggest that the changes in the configuration of PABP induced by interactions with various effector molecules, such as poly(A) and PABP-interacting protein 2, play pivotal roles in its function.
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Affiliation(s)
- Seung Hwan Lee
- School of Interdisciplinary Bioscience & Bioengineering, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Korea, Department of Physics, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Korea, Department of Life Sciences, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Korea and Division of Integrative Biosciences & Biotechnology, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Korea
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35
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McKinney C, Yu D, Mohr I. A new role for the cellular PABP repressor Paip2 as an innate restriction factor capable of limiting productive cytomegalovirus replication. Genes Dev 2013; 27:1809-20. [PMID: 23964095 PMCID: PMC3759697 DOI: 10.1101/gad.221341.113] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Here, Mohr and colleagues establish a role for the poly(A)-binding protein (PABP) repressor Paip2 in viral infection. The investigators find that human cytomegalovirus (HCMV) infection causes the up-regulation of Paip2 as well as PABP. The data indicate that Paip2 accumulation represents an innate host response to counteract the virus-induced increase in PABP abundance, limit the assembly of translation initiation factor complexes, and restrict viral growth. Paip2 thus plays a significant role in an innate defense mechanism to restrict viral protein synthesis and replication. The capacity of polyadenylate-binding protein PABPC1 (PABP1) to stimulate translation is regulated by its repressor, Paip2. Paradoxically, while PABP accumulation promotes human cytomegalovirus (HCMV) protein synthesis, we show that this is accompanied by an analogous increase in the abundance of Paip2 and EDD1, an E3 ubiquitin ligase that destabilizes Paip2. Coordinate control of PABP1, Paip2, and EDD1 required the virus-encoded UL38 mTORC1 activator and resulted in augmented Paip2 synthesis, stability, and association with PABP1. Paip2 synthesis also increased following serum stimulation of uninfected normal fibroblasts, suggesting that this coregulation may play a role in how uninfected cells respond to stress. Significantly, Paip2 accumulation was dependent on PABP accrual, as preventing PABP1 accumulation suppressed viral replication and inhibited the corresponding Paip2 increase. Furthermore, depleting Paip2 restored the ability of infected cells to assemble the translation initiation factor eIF4F, promoting viral protein synthesis and replication without increasing PABP1. This establishes a new role for the cellular PABP1 inhibitor Paip2 as an innate defense that restricts viral protein synthesis and replication. Moreover, it illustrates how a stress-induced rise in PABP1 triggered by virus infection can counter and surpass a corresponding increase in Paip2 abundance and stability.
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Affiliation(s)
- Caleb McKinney
- Department of Microbiology, New York University Cancer Institute, New York University School of Medicine, New York, New York 10016, USA
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Khoutorsky A, Yanagiya A, Gkogkas CG, Fabian MR, Prager-Khoutorsky M, Cao R, Gamache K, Bouthiette F, Parsyan A, Sorge RE, Mogil JS, Nader K, Lacaille JC, Sonenberg N. Control of synaptic plasticity and memory via suppression of poly(A)-binding protein. Neuron 2013; 78:298-311. [PMID: 23622065 DOI: 10.1016/j.neuron.2013.02.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2013] [Indexed: 10/26/2022]
Abstract
Control of protein synthesis is critical for synaptic plasticity and memory formation. However, the molecular mechanisms linking neuronal activity to activation of mRNA translation are not fully understood. Here, we report that the translational repressor poly(A)-binding protein (PABP)-interacting protein 2A (PAIP2A), an inhibitor of PABP, is rapidly proteolyzed by calpains in stimulated neurons and following training for contextual memory. Paip2a knockout mice exhibit a lowered threshold for the induction of sustained long-term potentiation and an enhancement of long-term memory after weak training. Translation of CaMKIIα mRNA is enhanced in Paip2a⁻/⁻ slices upon tetanic stimulation and in the hippocampus of Paip2a⁻/⁻ mice following contextual fear learning. We demonstrate that activity-dependent degradation of PAIP2A relieves translational inhibition of memory-related genes through PABP reactivation and conclude that PAIP2A is a pivotal translational regulator of synaptic plasticity and memory.
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Affiliation(s)
- Arkady Khoutorsky
- Department of Biochemistry and Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, QC H3A 1A3, Canada
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Svitkin YV, Yanagiya A, Karetnikov AE, Alain T, Fabian MR, Khoutorsky A, Perreault S, Topisirovic I, Sonenberg N. Control of translation and miRNA-dependent repression by a novel poly(A) binding protein, hnRNP-Q. PLoS Biol 2013; 11:e1001564. [PMID: 23700384 PMCID: PMC3660254 DOI: 10.1371/journal.pbio.1001564] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/10/2013] [Indexed: 02/05/2023] Open
Abstract
The heterogeneous nuclear ribonucleoprotein Q2 competitively binds mRNA poly(A) tails to regulate translational and miRNA-related functions of PABP. Translation control often operates via remodeling of messenger ribonucleoprotein particles. The poly(A) binding protein (PABP) simultaneously interacts with the 3′ poly(A) tail of the mRNA and the eukaryotic translation initiation factor 4G (eIF4G) to stimulate translation. PABP also promotes miRNA-dependent deadenylation and translational repression of target mRNAs. We demonstrate that isoform 2 of the mouse heterogeneous nuclear protein Q (hnRNP-Q2/SYNCRIP) binds poly(A) by default when PABP binding is inhibited. In addition, hnRNP-Q2 competes with PABP for binding to poly(A) in vitro. Depleting hnRNP-Q2 from translation extracts stimulates cap-dependent and IRES-mediated translation that is dependent on the PABP/poly(A) complex. Adding recombinant hnRNP-Q2 to the extracts inhibited translation in a poly(A) tail-dependent manner. The displacement of PABP from the poly(A) tail by hnRNP-Q2 impaired the association of eIF4E with the 5′ m7G cap structure of mRNA, resulting in the inhibition of 48S and 80S ribosome initiation complex formation. In mouse fibroblasts, silencing of hnRNP-Q2 stimulated translation. In addition, hnRNP-Q2 impeded let-7a miRNA-mediated deadenylation and repression of target mRNAs, which require PABP. Thus, by competing with PABP, hnRNP-Q2 plays important roles in the regulation of global translation and miRNA-mediated repression of specific mRNAs. The regulation of mRNA translation and stability is of paramount importance for almost every cellular function. In eukaryotes, the poly(A) binding protein (PABP) is a central regulator of both global and mRNA-specific translation. PABP simultaneously interacts with the 3′ poly(A) tail of the mRNA and the eukaryotic translation initiation factor 4G (eIF4G). These interactions circularize the mRNA and stimulate translation. PABP also regulates specific mRNAs by promoting miRNA-dependent deadenylation and translational repression. A key step in understanding PABP's functions is to identify factors that affect its association with the poly(A) tail. Here we show that the cytoplasmic isoform of the mouse heterogeneous nuclear ribonucleoprotein Q (hnRNP-Q2/SYNCRIP), which exhibits binding preference to poly(A), interacts with the poly(A) tail by default when PABP binding is inhibited. In addition, hnRNP-Q2 competes with PABP for binding to the poly(A) tail. Depleting hnRNP-Q2 stimulates translation in cell-free extracts and in cultured cells, in agreement with its function as translational repressor. In addition, hnRNP-Q2 impeded miRNA-mediated deadenylation and repression of target mRNAs, which requires PABP. Thus, competition from hnRNP-Q2 provides a novel mechanism by which multiple functions of PABP are regulated. This regulation could play important roles in various biological processes, such as development, viral infection, and human disease.
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Affiliation(s)
- Yuri V. Svitkin
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Akiko Yanagiya
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Alexey E. Karetnikov
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Tommy Alain
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Marc R. Fabian
- Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Oncology, McGill University, Montreal, Quebec, Canada
| | - Arkady Khoutorsky
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Sandra Perreault
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
| | - Ivan Topisirovic
- Lady Davis Institute for Medical Research, Jewish General Hospital, Department of Oncology, McGill University, Montreal, Quebec, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
- * E-mail:
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LABRECQUE RÉMI, VIGNEAULT CHRISTIAN, BLONDIN PATRICK, SIRARD MARCANDRÉ. Gene Expression Analysis of Bovine Oocytes With High Developmental Competence Obtained From FSH-Stimulated Animals. Mol Reprod Dev 2013; 80:428-40. [DOI: 10.1002/mrd.22177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 03/21/2013] [Indexed: 11/11/2022]
Affiliation(s)
- RÉMI LABRECQUE
- Centre de recherche en biologie de la reproduction, Faculté des sciences de l'Agriculture et de l'Alimentation, Département des Sciences Animales, Pavillon INAF; Université Laval; Québec; Québec; Canada
| | | | | | - MARC-ANDRÉ SIRARD
- Centre de recherche en biologie de la reproduction, Faculté des sciences de l'Agriculture et de l'Alimentation, Département des Sciences Animales, Pavillon INAF; Université Laval; Québec; Québec; Canada
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Yoon TD, Lee HW, Kim YS, Choi HJ, Moon JO, Yoon S. Identification and analysis of expressed genes using a cDNA library from rat thymus during regeneration following cyclophosphamide-induced T cell depletion. Int J Mol Med 2013; 31:731-9. [PMID: 23314113 DOI: 10.3892/ijmm.2013.1238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 12/12/2012] [Indexed: 11/05/2022] Open
Abstract
Understanding the mechanisms of thymus regeneration is necessary for designing strategies to enhance host immunity when immune function is suppressed due to T cell depletion. In this study, expressed sequence tag (EST) analysis was performed following generation of a regenerating thymus cDNA library to identify genes expressed in thymus regeneration. A total of 1,000 ESTs were analyzed, of which 770 (77%) matched to known genes, 178 matched to unknown genes (17.8%) and 52 (5.2%) did not match any known sequences. The ESTs matched to known genes were grouped into eight functional categories: gene/protein synthesis (28%), metabolism (24%), cell signaling and communication (17%), cell structure and motility (6%), cell/organism defense and homeostasis (6%), cell division (3%), cell death/apoptosis (2%), and unclassified genes (14%). Based on the data of RT-PCR analysis, the expression of TLP, E2IG2, pincher, Paip2, TGF-β1, 4-1BB and laminin α3 genes was increased during thymus regeneration. These results provide extensive molecular information, for the first time, on thymus regeneration indicating that the regenerating thymus cDNA library may be a useful source for identifying various genes expressed during thymus regeneration.
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Affiliation(s)
- Tae-Deuk Yoon
- Department of Anatomy, Pusan National University, School of Medicine, Yangsan, Gyeongsangnam-do 626-870, Republic of Korea
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Delbes G, Yanagiya A, Sonenberg N, Robaire B. PABP interacting protein 2A (PAIP2A) regulates specific key proteins during spermiogenesis in the mouse. Biol Reprod 2012; 86:95. [PMID: 22190698 DOI: 10.1095/biolreprod.111.092619] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
During spermiogenesis, expression of the specific proteins needed for proper differentiation of male germ cells is under translational control. We have shown that PAIP2A is a major translational regulator involved in the maturation of male germ cells and male fertility. To identify the proteins controlled by PAIP2A during spermiogenesis, we characterized the proteomic profiles of elongated spermatids from wild-type (WT) mice and mice that were Paip2a/Paip2b double-null mutants (DKO). Elongated spermatid populations were obtained and proteins were extracted and separated on gradient polyacrylamide gels. The gels were digested with trypsin and peptides were identified by mass spectrometry. We identified 632 proteins with at least two unique peptides and a confidence level of 95%. Only 209 proteins were consistently detected in WT or DKO replicates with more than five spectra. Twenty-nine proteins were differentially expressed with at least a 1.5-fold change; 10 and 19 proteins were down- and up-regulated, respectively, in DKO compared to WT mice. We confirmed the significantly different expression levels of three proteins, EIF4G1, AKAP4, and HK1, by Western blot analysis. We have characterized novel proteins that have their expression controlled by PAIP2A; of these, 50% are involved in flagellar structure and sperm motility. Although several proteins affected by abrogation of Paip2a have established roles in reproduction, the roles of many others remain to be determined.
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Affiliation(s)
- Geraldine Delbes
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
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Kikuchi K, Shimizu S, Sato Y, Morishita EC, Takénaka A. Crystallization of oligonucleotides containing A-rich repeats suggests a structural contribution to the autoregulation mechanism of PABP translation. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:185-9. [PMID: 22297995 PMCID: PMC3274399 DOI: 10.1107/s1744309111052110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 12/02/2011] [Indexed: 11/10/2022]
Abstract
Eukaryotic poly(A)-binding protein (PABP) commonly binds to the 3'-UTR poly(A) tail of every mRNA, but it also binds to the 5'-UTR of PABP mRNA for autoregulation of its expression. In the sequence of the latter binding site, the contiguous A residues are segmented discretely by the insertion of short pyrimidine oligonucleotides as linkers, so that (A)(6-8) segments are repeated six times. This differs from the poly(A)-tail sequence, which has a higher binding affinity for PABP. In order to examine whether the A-rich repeats have a functional structure, several RNA/DNA analogues were subjected to crystallization. It was found that some of them could be crystallized. Single crystals thus obtained diffracted to 4.1 Å resolution. The fact that the repeated sequences can be crystallized suggests the possibility that the autoregulatory sequence in PABP mRNA has a specific structure which impedes the binding of PABP. When PABP is excessively produced, it could bind to this sequence by releasing the structure in order to interfere with initiation-complex formation for suppression of PABP translation. Otherwise, PABP at low concentration preferentially binds to the poly(A) tail of PABP mRNA.
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Affiliation(s)
- Keita Kikuchi
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 226-8501, Japan
| | - Satoru Shimizu
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 226-8501, Japan
| | - Yoshiteru Sato
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 226-8501, Japan
| | - Ella Czarina Morishita
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 226-8501, Japan
| | - Akio Takénaka
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuda, Midori-ku, Yokohama 226-8501, Japan
- Graduate School of Science and Engineering, Iwaki-Meisei University, Chuodai-iino, Iwaki, Fukushima 970-8551, Japan
- Faculty of Pharmacy, Iwaki-Meisei University, Chuodai-iino, Iwaki, Fukushima 970-8551, Japan
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Aalto MK, Helenius E, Kariola T, Pennanen V, Heino P, Hõrak H, Puzõrjova I, Kollist H, Palva ET. ERD15--an attenuator of plant ABA responses and stomatal aperture. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 182:19-28. [PMID: 22118612 DOI: 10.1016/j.plantsci.2011.08.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 04/10/2011] [Accepted: 08/23/2011] [Indexed: 05/24/2023]
Abstract
Plants are continuously challenged by abiotic and biotic stress factors and need to mount appropriate responses to ensure optimal growth and survival. We have identified ERD15 as a central component in several stress responses in Arabidopsis thaliana. Comparative genomics demonstrates that ERD15 is a member of a small but highly conserved protein family ubiquitous but specific to the plant kingdom. The origin of ERD15 family of proteins can be traced to the time of emergence of land plants. The presence of the conserved PAM2 motif in ERD15 proteins is indicative of a possible interaction with poly(A) binding proteins and could suggest a role in posttranscriptional regulation of gene expression. The function of the other highly conserved motifs in ERD15 remains to be elucidated. The biological role of all ERD15 family members studied so far appears associated to stress responses and stress adaptation. Studies in Arabidopsis demonstrate a role in abiotic stress tolerance where ERD15 is a negative regulator of ABA signaling. The role in ABA signaling may also explain how ERD15 regulates stomatal aperture and consequently controls plant water relations.
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Affiliation(s)
- Markku K Aalto
- Department of Biosciences, Division of Genetics, POB 56, Viikki Biocenter, University of Helsinki, FI-00014 Helsinki, Finland.
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Functional genomic and advanced genetic studies reveal novel insights into the metabolism, regulation, and biology of Haloferax volcanii. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2011; 2011:602408. [PMID: 22190865 PMCID: PMC3235422 DOI: 10.1155/2011/602408] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 07/04/2011] [Accepted: 09/06/2011] [Indexed: 11/18/2022]
Abstract
The genome sequence of Haloferax volcanii is available and several comparative genomic in silico studies were performed that yielded novel insight for example into protein export, RNA modifications, small non-coding RNAs, and ubiquitin-like Small Archaeal Modifier Proteins. The full range of functional genomic methods has been established and results from transcriptomic, proteomic and metabolomic studies are discussed. Notably, Hfx. volcanii is together with Halobacterium salinarum the only prokaryotic species for which a translatome analysis has been performed. The results revealed that the fraction of translationally-regulated genes in haloarchaea is as high as in eukaryotes. A highly efficient genetic system has been established that enables the application of libraries as well as the parallel generation of genomic deletion mutants. Facile mutant generation is complemented by the possibility to culture Hfx. volcanii in microtiter plates, allowing the phenotyping of mutant collections. Genetic approaches are currently used to study diverse biological questions–from replication to posttranslational modification—and selected results are discussed. Taken together, the wealth of functional genomic and genetic tools make Hfx. volcanii a bona fide archaeal model species, which has enabled the generation of important results in recent years and will most likely generate further breakthroughs in the future.
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Miroci H, Schob C, Kindler S, Ölschläger-Schütt J, Fehr S, Jungenitz T, Schwarzacher SW, Bagni C, Mohr E. Makorin ring zinc finger protein 1 (MKRN1), a novel poly(A)-binding protein-interacting protein, stimulates translation in nerve cells. J Biol Chem 2011; 287:1322-34. [PMID: 22128154 DOI: 10.1074/jbc.m111.315291] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The poly(A)-binding protein (PABP), a key component of different ribonucleoprotein complexes, plays a crucial role in the control of mRNA translation rates, stability, and subcellular targeting. In this study we identify RING zinc finger protein Makorin 1 (MKRN1), a bona fide RNA-binding protein, as a binding partner of PABP that interacts with PABP in an RNA-independent manner. In rat brain, a so far uncharacterized short MKRN1 isoform, MKRN1-short, predominates and is detected in forebrain nerve cells. In neuronal dendrites, MKRN1-short co-localizes with PABP in granule-like structures, which are morphological correlates of sites of mRNA metabolism. Moreover, in primary rat neurons MKRN1-short associates with dendritically localized mRNAs. When tethered to a reporter mRNA, MKRN1-short significantly enhances reporter protein synthesis. Furthermore, after induction of synaptic plasticity via electrical stimulation of the perforant path in vivo, MKRN1-short specifically accumulates in the activated dendritic lamina, the middle molecular layer of the hippocampal dentate gyrus. Collectively, these data indicate that in mammalian neurons MKRN1-short interacts with PABP to locally control the translation of dendritic mRNAs at synapses.
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Affiliation(s)
- Hatmone Miroci
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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Fukaya T, Tomari Y. PABP is not essential for microRNA-mediated translational repression and deadenylation in vitro. EMBO J 2011; 30:4998-5009. [PMID: 22117217 DOI: 10.1038/emboj.2011.426] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 11/07/2011] [Indexed: 12/31/2022] Open
Abstract
MicroRNAs silence their complementary target genes via formation of the RNA-induced silencing complex (RISC) that contains an Argonaute (Ago) protein at its core. It was previously proposed that GW182, an Ago-associating protein, directly binds to poly(A)-binding protein (PABP) and interferes with its function, leading to silencing of the target mRNAs. Here we show that Drosophila Ago1-RISC induces silencing via two independent pathways: shortening of the poly(A) tail and pure repression of translation. Our data suggest that although PABP generally modulates poly(A) length and translation efficiency, neither PABP function nor GW182-PABP interaction is a prerequisite for these two silencing pathways. Instead, we propose that each of the multiple functional domains within GW182 has a potential for silencing, and yet they need to act together in the context of full-length GW182 to exert maximal silencing.
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Affiliation(s)
- Takashi Fukaya
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan
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46
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Peixeiro I, Inácio Â, Barbosa C, Silva AL, Liebhaber SA, Romão L. Interaction of PABPC1 with the translation initiation complex is critical to the NMD resistance of AUG-proximal nonsense mutations. Nucleic Acids Res 2011; 40:1160-73. [PMID: 21989405 PMCID: PMC3273812 DOI: 10.1093/nar/gkr820] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a surveillance pathway that recognizes and rapidly degrades mRNAs containing premature termination codons (PTC). The strength of the NMD response appears to reflect multiple determinants on a target mRNA. We have previously reported that mRNAs containing PTCs in close proximity to the translation initiation codon (AUG-proximal PTCs) can substantially evade NMD. Here, we explore the mechanistic basis for this NMD resistance. We demonstrate that translation termination at an AUG-proximal PTC lacks the ribosome stalling that is evident in an NMD-sensitive PTC. This difference is associated with demonstrated interactions of the cytoplasmic poly(A)-binding protein 1, PABPC1, with the cap-binding complex subunit, eIF4G and the 40S recruitment factor eIF3 as well as the ribosome release factor, eRF3. These interactions, in combination, underlie critical 3′–5′ linkage of translation initiation with efficient termination at the AUG-proximal PTC and contribute to an NMD-resistant PTC definition at an early phase of translation elongation.
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Affiliation(s)
- Isabel Peixeiro
- Departamento de Genética, Instituto Nacional de Saúde Dr. Ricardo Jorge, 1649-016 Lisboa, Portugal
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Suppression of cellular transformation by poly (A) binding protein interacting protein 2 (Paip2). PLoS One 2011; 6:e25116. [PMID: 21957478 PMCID: PMC3177865 DOI: 10.1371/journal.pone.0025116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/24/2011] [Indexed: 12/28/2022] Open
Abstract
Controlling translation is crucial for the homeostasis of a cell. Its deregulation can facilitate the development and progression of many diseases including cancer. Poly (A) binding protein interacting protein 2 (Paip2) inhibits efficient initiation of translation by impairing formation of the necessary closed loop of mRNA. The over production of Paip2 in the presence of a constitutively active form of hRasV12 can reduce colony formation in a semi-solid matrix and focus formation on a cell monolayer. The ability of Paip2 to bind to Pabp is required to suppress the transformed phenotype mediated by hRasV12. These observations indicate that Paip2 is able to function as a tumor suppressor.
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48
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Importin alpha-mediated nuclear import of cytoplasmic poly(A) binding protein occurs as a direct consequence of cytoplasmic mRNA depletion. Mol Cell Biol 2011; 31:3113-25. [PMID: 21646427 DOI: 10.1128/mcb.05402-11] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Recent studies have found the cytoplasmic poly(A) binding protein (PABPC) to have opposing effects on gene expression when concentrated in the cytoplasm versus in the nucleus. PABPC is predominantly cytoplasmic at steady state, where it enhances protein synthesis through simultaneous interactions with mRNA and translation factors. However, it accumulates dramatically within the nucleus in response to various pathogenic and nonpathogenic stresses, leading to an inhibition of mRNA export. The molecular events that trigger relocalization of PABPC and the mechanisms by which it translocates into the nucleus to block gene expression are not understood. Here, we reveal an RNA-based mechanism of retaining PABPC in the cytoplasm. Expression either of viral proteins that promote mRNA turnover or of a cytoplasmic deadenylase drives nuclear relocalization of PABPC in a manner dependent on the PABPC RNA recognition motifs (RRMs). Using multiple independent binding sites within its RRMs, PABPC interacts with importin α, a component of the classical import pathway. Finally, we demonstrate that the direct association of PABPC with importin α is antagonized by the presence of poly(A) RNA, supporting a model in which RNA binding masks nuclear import signals within the PABPC RRMs, thereby ensuring efficient cytoplasmic retention of this protein in normal cells. These findings further suggest that cells must carefully calibrate the ratio of PABPC to mRNA, as events that offset this balance can dramatically influence gene expression.
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Huntzinger E, Braun JE, Heimstädt S, Zekri L, Izaurralde E. Two PABPC1-binding sites in GW182 proteins promote miRNA-mediated gene silencing. EMBO J 2010; 29:4146-60. [PMID: 21063388 PMCID: PMC3018788 DOI: 10.1038/emboj.2010.274] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Accepted: 10/12/2010] [Indexed: 12/14/2022] Open
Abstract
Previous studies have suggested that the mechanism of miRNA-mediated silencing may differ between human and Drosophila cells. Here, a direct comparison demonstrates that the mechanism is conserved and the GW182–PABP interaction is required for silencing in vivo. miRNA-mediated gene silencing requires the GW182 proteins, which are characterized by an N-terminal domain that interacts with Argonaute proteins (AGOs), and a C-terminal silencing domain (SD). In Drosophila melanogaster (Dm) GW182 and a human (Hs) orthologue, TNRC6C, the SD was previously shown to interact with the cytoplasmic poly(A)-binding protein (PABPC1). Here, we show that two regions of GW182 proteins interact with PABPC1: the first contains a PABP-interacting motif 2 (PAM2; as shown before for TNRC6C) and the second contains the M2 and C-terminal sequences in the SD. The latter mediates indirect binding to the PABPC1 N-terminal domain. In D. melanogaster cells, the second binding site dominates; however, in HsTNRC6A–C the PAM2 motif is essential for binding to both Hs and DmPABPC1. Accordingly, a single amino acid substitution in the TNRC6A–C PAM2 motif abolishes the interaction with PABPC1. This mutation also impairs TNRC6s silencing activity. Our findings reveal that despite species-specific differences in the relative strength of the PABPC1-binding sites, the interaction between GW182 proteins and PABPC1 is critical for miRNA-mediated silencing in animal cells.
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Affiliation(s)
- Eric Huntzinger
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
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Yanagiya A, Delbes G, Svitkin YV, Robaire B, Sonenberg N. The poly(A)-binding protein partner Paip2a controls translation during late spermiogenesis in mice. J Clin Invest 2010; 120:3389-400. [PMID: 20739757 DOI: 10.1172/jci43350] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 07/14/2010] [Indexed: 11/17/2022] Open
Abstract
Translational control plays a key role in late spermiogenesis. A number of mRNAs encoding proteins required for late spermiogenesis are expressed in early spermatids but are stored as translationally inactive messenger ribonucleoprotein particles (mRNPs). The translation of these mRNAs is associated with shortening of their poly(A) tail in late spermiogenesis. Poly(A)-binding protein (Pabp) plays an important role in mRNA stabilization and translation. Three Pabp-interacting proteins, Paip1, Paip2a, and Paip2b, have been described. Paip2a is expressed in late spermatids. To investigate the role of Paip2 in spermiogenesis, we generated mice with knockout of either Paip2a or Paip2b and double-KO (DKO) mice lacking both Paip2a and Paip2b. Paip2a-KO and Paip2a/Paip2b-DKO mice exhibited male infertility. Translation of several mRNAs encoding proteins essential to male germ cell development was inhibited in late spermiogenesis in Paip2a/Paip2b-DKO mice, resulting in defective elongated spermatids. Inhibition of translation in Paip2a/Paip2b-DKO mice was caused by aberrant increased expression of Pabp, which impaired the interaction between eukaryotic initiation factor 4E (eIF4E) and the cap structure at the 5' end of the mRNA. We therefore propose a model whereby efficient mRNA translation in late spermiogenesis occurs at an optimal concentration of Pabp, a condition not fulfilled in Paip2a/Paip2b-DKO mice.
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Affiliation(s)
- Akiko Yanagiya
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, Montreal, Quebec, Canada
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