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Taniguchi I, Hirose T, Ohno M. The RNA helicase DDX39 contributes to the nuclear export of spliceosomal U snRNA by loading of PHAX onto RNA. Nucleic Acids Res 2024; 52:10668-10682. [PMID: 39011894 PMCID: PMC11417407 DOI: 10.1093/nar/gkae622] [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: 09/28/2023] [Revised: 07/01/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024] Open
Abstract
RNA helicases are involved in RNA metabolism in an ATP-dependent manner. Although many RNA helicases unwind the RNA structure and/or remove proteins from the RNA, some can load their interacting proteins onto RNAs. Here, we developed an in vitro strategy to identify the ATP-dependent factors involved in spliceosomal uridine-rich small nuclear RNA (U snRNA) export. We identified the RNA helicase UAP56/DDX39B, a component of the mRNA export complex named the transcription-export (TREX) complex, and its closely related RNA helicase URH49/DDX39A as the factors that stimulated RNA binding of PHAX, an adapter protein for U snRNA export. ALYREF, another TREX component, acted as a bridge between PHAX and UAP56/DDX39B. We also showed that UAP56/DDX39B and ALYREF participate in U snRNA export through a mechanism distinct from that of mRNA export. This study describes a novel aspect of the TREX components for U snRNP biogenesis and highlights the loading activity of RNA helicases.
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Affiliation(s)
- Ichiro Taniguchi
- Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Tetsuro Hirose
- Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
- Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Suita 565-0871, Japan
| | - Mutsuhito Ohno
- Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
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2
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Tapescu I, Cherry S. DDX RNA helicases: key players in cellular homeostasis and innate antiviral immunity. J Virol 2024:e0004024. [PMID: 39212449 DOI: 10.1128/jvi.00040-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
RNA helicases are integral in RNA metabolism, performing important roles in cellular homeostasis and stress responses. In particular, the DExD/H-box (DDX) helicase family possesses a conserved catalytic core that binds structural features rather than specific sequences in RNA targets. DDXs have critical roles in all aspects of RNA metabolism including ribosome biogenesis, translation, RNA export, and RNA stability. Importantly, functional specialization within this family arises from divergent N and C termini and is driven at least in part by gene duplications with 18 of the 42 human helicases having paralogs. In addition to their key roles in the homeostatic control of cellular RNA, these factors have critical roles in RNA virus infection. The canonical RIG-I-like receptors (RLRs) play pivotal roles in cytoplasmic sensing of viral RNA structures, inducing antiviral gene expression. Additional RNA helicases function as viral sensors or regulators, further diversifying the innate immune defense arsenal. Moreover, some of these helicases have been coopted by viruses to facilitate their replication. Altogether, DDX helicases exhibit functional specificity, playing intricate roles in RNA metabolism and host defense. This review will discuss the mechanisms by which these RNA helicases recognize diverse RNA structures in cellular and viral RNAs, and how this impacts RNA processing and innate immune responses.
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Affiliation(s)
- Iulia Tapescu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Biophysics Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sara Cherry
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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3
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Banerjee S, Nagasawa C, Widen S, Garcia-Blanco M. Parsing the roles of DExD-box proteins DDX39A and DDX39B in alternative RNA splicing. Nucleic Acids Res 2024; 52:8534-8551. [PMID: 38801080 PMCID: PMC11317157 DOI: 10.1093/nar/gkae431] [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: 01/28/2024] [Revised: 05/01/2024] [Accepted: 05/12/2024] [Indexed: 05/29/2024] Open
Abstract
DExD-box RNA proteins DDX39A and DDX39B are highly homologous paralogs that are conserved in vertebrates. They are required for energy-driven reactions involved in RNA processing. Although we have some understanding of how their functions overlap in RNA nuclear export, our knowledge of whether or not these proteins have specific or redundant functions in RNA splicing is limited. Our previous work has shown that DDX39B is responsible for regulating the splicing of important immune transcripts IL7R and FOXP3. In this study, we aimed to investigate whether DDX39A, a highly homologous paralog of DDX39B, plays a similar role in regulating alternative RNA splicing. We find that DDX39A and DDX39B have significant redundancy in their gene targets, but there are targets that uniquely require one or the other paralog. For instance, DDX39A is incapable of complementing defective splicing of IL7R exon 6 when DDX39B is depleted. This exon and other cassette exons that specifically depend on DDX39B have U-poor/C-rich polypyrimidine tracts in the upstream intron and this variant polypyrimidine tract is required for DDX39B dependency. This study provides evidence that despite a high degree of functional redundancy, DDX39A and DDX39B are selectively required for the splicing of specific pre-mRNAs.
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Affiliation(s)
- Shefali Banerjee
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Chloe K Nagasawa
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
- Human Pathophysiology and Translational Medicine Program, Institute for Translational Sciences, University of Texas Medical Branch, Galveston, TX 77555-5302, USA
| | - Steven G Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
| | - Mariano A Garcia-Blanco
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, VA 22903, USA
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77550, USA
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Fujita KI, Yamazaki T, Mayeda A, Masuda S. Terminal regions of UAP56 and URH49 are required for their distinct complex formation functioning to an essential role in mRNA processing and export. Biochem Biophys Res Commun 2024; 703:149682. [PMID: 38377942 DOI: 10.1016/j.bbrc.2024.149682] [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: 02/03/2024] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/22/2024]
Abstract
UAP56 and URH49 are closely related RNA helicases that function in selective mRNA processing and export pathways to fine-tune gene expression through distinct complex formations. The complex formation of UAP56 and URH49 is believed to play a crucial role in regulating target mRNAs. However, the mechanisms underlying this complex formation have not been fully elucidated. Here we identified the regions essential for the complex formation of both helicases. The terminal regions of UAP56 and the C-terminal region of URH49 were indispensable for their respective complex formation. Further analysis revealed that a specific amino acid at the C-terminus of UAP56 is critical for its complex formation. Alanine substitution of this amino acid impairs its complex formation and subsequently affected its mRNA processing and export activity. Our study provides a deeper understanding of the basis for the complex formation between UAP56 and URH49.
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Affiliation(s)
- Ken-Ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan; Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan; Division of Cancer Stem Cell, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan
| | - Tomohiro Yamazaki
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan; Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara, 631-8505, Japan; Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, Nara, Nara, Japan; Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara, 631-8505, Japan; Antiaging Center, Kindai University, Higashiosaka, Osaka, 577-8502, Japan.
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5
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Fujita KI, Ito M, Irie M, Harada K, Fujiwara N, Ikeda Y, Yoshioka H, Yamazaki T, Kojima M, Mikami B, Mayeda A, Masuda S. Structural differences between the closely related RNA helicases, UAP56 and URH49, fashion distinct functional apo-complexes. Nat Commun 2024; 15:455. [PMID: 38225262 PMCID: PMC10789772 DOI: 10.1038/s41467-023-44217-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 12/05/2023] [Indexed: 01/17/2024] Open
Abstract
mRNA export is an essential pathway for the regulation of gene expression. In humans, closely related RNA helicases, UAP56 and URH49, shape selective mRNA export pathways through the formation of distinct complexes, known as apo-TREX and apo-AREX complexes, and their subsequent remodeling into similar ATP-bound complexes. Therefore, defining the unidentified components of the apo-AREX complex and elucidating the molecular mechanisms underlying the formation of distinct apo-complexes is key to understanding their functional divergence. In this study, we identify additional apo-AREX components physically and functionally associated with URH49. Furthermore, by comparing the structures of UAP56 and URH49 and performing an integrated analysis of their chimeric mutants, we exhibit unique structural features that would contribute to the formation of their respective complexes. This study provides insights into the specific structural and functional diversification of these two helicases that diverged from the common ancestral gene Sub2.
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Affiliation(s)
- Ken-Ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan.
- Division of Cancer Stem Cell, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
| | - Misa Ito
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Midori Irie
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Kotaro Harada
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Naoko Fujiwara
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Yuya Ikeda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Hanae Yoshioka
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Tomohiro Yamazaki
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Masaki Kojima
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Bunzo Mikami
- Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, 611-0011, Japan
- Institute of Advanced Energy, Kyoto University, Kyoto, 611-0011, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara, 631-8505, Japan.
- Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara, 631-8505, Japan.
- Antiaging Center, Kindai University, Higashiosaka, Osaka, 577-8502, Japan.
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6
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SRSF3 facilitates replication of influenza A virus via binding and promoting the transport of viral mRNA. Vet Microbiol 2022; 266:109343. [DOI: 10.1016/j.vetmic.2022.109343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 01/11/2022] [Accepted: 01/16/2022] [Indexed: 12/17/2022]
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7
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Yamanaka Y, Ishizuka T, Fujita KI, Fujiwara N, Kurata M, Masuda S. CHERP Regulates the Alternative Splicing of pre-mRNAs in the Nucleus. Int J Mol Sci 2022; 23:ijms23052555. [PMID: 35269695 PMCID: PMC8910253 DOI: 10.3390/ijms23052555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/23/2022] [Accepted: 02/23/2022] [Indexed: 12/17/2022] Open
Abstract
Calcium homeostasis endoplasmic reticulum protein (CHERP) is colocalized with the inositol 1,4,5-trisphosphate receptor (IP3R) in the endoplasmic reticulum or perinuclear region, and has been involved in intracellular calcium signaling. Structurally, CHERP carries the nuclear localization signal and arginine/serine-dipeptide repeats, like domain, and interacts with the spliceosome. However, the exact function of CHERP in the nucleus remains unknown. Here, we showed that poly(A)+ RNAs accumulated in the nucleus of CHERP-depleted U2OS cells. Our global analysis revealed that CHERP regulated alternative mRNA splicing events by interaction with U2 small nuclear ribonucleoproteins (U2 snRNPs) and U2 snRNP-related proteins. Among the five alternative splicing patterns analyzed, intron retention was the most frequently observed event. This was in accordance with the accumulation of poly(A)+ RNAs in the nucleus. Furthermore, intron retention and cassette exon choices were influenced by the strength of the 5′ or 3′ splice site, the branch point site, GC content, and intron length. In addition, CHERP depletion induced anomalies in the cell cycle progression into the M phase, and abnormal cell division. These results suggested that CHERP is involved in the regulation of alternative splicing.
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Affiliation(s)
- Yasutaka Yamanaka
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; (Y.Y.); (T.I.); (K.-i.F.); (N.F.); (M.K.)
| | - Takaki Ishizuka
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; (Y.Y.); (T.I.); (K.-i.F.); (N.F.); (M.K.)
| | - Ken-ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; (Y.Y.); (T.I.); (K.-i.F.); (N.F.); (M.K.)
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan
| | - Naoko Fujiwara
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; (Y.Y.); (T.I.); (K.-i.F.); (N.F.); (M.K.)
| | - Masashi Kurata
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; (Y.Y.); (T.I.); (K.-i.F.); (N.F.); (M.K.)
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan; (Y.Y.); (T.I.); (K.-i.F.); (N.F.); (M.K.)
- Department of Food Science and Nutrition, Faculty of Agriculture, Kindai University, Nara 631-8505, Japan
- Correspondence: ; Tel.: +81-742-43-1713
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8
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Caba L, Florea L, Gug C, Dimitriu DC, Gorduza EV. Circular RNA-Is the Circle Perfect? Biomolecules 2021; 11:biom11121755. [PMID: 34944400 PMCID: PMC8698871 DOI: 10.3390/biom11121755] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022] Open
Abstract
Circular RNA (circRNA) is a distinct class of non-coding RNA produced, in principle, using a back-splicing mechanism, conserved during evolution, with increased stability and a tissue-dependent expression. Circular RNA represents a functional molecule with roles in the regulation of transcription and splicing, microRNA sponge, and the modulation of protein–protein interaction. CircRNAs are involved in essential processes of life such as apoptosis, cell cycle, and proliferation. Due to the regulatory role (upregulation/downregulation) in pathogenic mechanisms of some diseases (including cancer), its potential roles as a biomarker or therapeutic target in these diseases were studied. This review focuses on the importance of circular RNA in cancer.
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Affiliation(s)
- Lavinia Caba
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
- Correspondence:
| | - Laura Florea
- Department of Nephrology-Internal Medicine, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
| | - Cristina Gug
- Microscopic Morphology Department, “Victor Babes” University of Medicine and Pharmacy, 300041 Timișoara, Romania;
| | - Daniela Cristina Dimitriu
- Department of Morpho-Functional Sciences II, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
| | - Eusebiu Vlad Gorduza
- Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania;
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The Mammalian Ecdysoneless Protein Interacts with RNA Helicase DDX39A To Regulate Nuclear mRNA Export. Mol Cell Biol 2021; 41:e0010321. [PMID: 33941617 PMCID: PMC8224239 DOI: 10.1128/mcb.00103-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The mammalian orthologue of ecdysoneless (ECD) protein is required for embryogenesis, cell cycle progression, and mitigation of endoplasmic reticulum stress. Here, we identified key components of the mRNA export complexes as binding partners of ECD and characterized the functional interaction of ECD with key mRNA export-related DEAD BOX protein helicase DDX39A. We find that ECD is involved in RNA export through its interaction with DDX39A. ECD knockdown (KD) blocks mRNA export from the nucleus to the cytoplasm, which is rescued by expression of full-length ECD but not an ECD mutant that is defective in interaction with DDX39A. We have previously shown that ECD protein is overexpressed in ErbB2+ breast cancers (BC). In this study, we extended the analyses to two publicly available BC mRNA The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) data sets. In both data sets, ECD mRNA overexpression correlated with short patient survival, specifically ErbB2+ BC. In the METABRIC data set, ECD overexpression also correlated with poor patient survival in triple-negative breast cancer (TNBC). Furthermore, ECD KD in ErbB2+ BC cells led to a decrease in ErbB2 mRNA level due to a block in its nuclear export and was associated with impairment of oncogenic traits. These findings provide novel mechanistic insight into the physiological and pathological functions of ECD.
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DEAD-Box RNA Helicases in Cell Cycle Control and Clinical Therapy. Cells 2021; 10:cells10061540. [PMID: 34207140 PMCID: PMC8234093 DOI: 10.3390/cells10061540] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 12/11/2022] Open
Abstract
Cell cycle is regulated through numerous signaling pathways that determine whether cells will proliferate, remain quiescent, arrest, or undergo apoptosis. Abnormal cell cycle regulation has been linked to many diseases. Thus, there is an urgent need to understand the diverse molecular mechanisms of how the cell cycle is controlled. RNA helicases constitute a large family of proteins with functions in all aspects of RNA metabolism, including unwinding or annealing of RNA molecules to regulate pre-mRNA, rRNA and miRNA processing, clamping protein complexes on RNA, or remodeling ribonucleoprotein complexes, to regulate gene expression. RNA helicases also regulate the activity of specific proteins through direct interaction. Abnormal expression of RNA helicases has been associated with different diseases, including cancer, neurological disorders, aging, and autosomal dominant polycystic kidney disease (ADPKD) via regulation of a diverse range of cellular processes such as cell proliferation, cell cycle arrest, and apoptosis. Recent studies showed that RNA helicases participate in the regulation of the cell cycle progression at each cell cycle phase, including G1-S transition, S phase, G2-M transition, mitosis, and cytokinesis. In this review, we discuss the essential roles and mechanisms of RNA helicases in the regulation of the cell cycle at different phases. For that, RNA helicases provide a rich source of targets for the development of therapeutic or prophylactic drugs. We also discuss the different targeting strategies against RNA helicases, the different types of compounds explored, the proposed inhibitory mechanisms of the compounds on specific RNA helicases, and the therapeutic potential of these compounds in the treatment of various disorders.
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