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Yang BZ, Liu MY, Chiu KL, Chien YL, Cheng CA, Chen YL, Tsui LY, Lin KR, Chu HPC, Wu CSP. DHX9 SUMOylation is required for the suppression of R-loop-associated genome instability. Nat Commun 2024; 15:6009. [PMID: 39019926 PMCID: PMC11255299 DOI: 10.1038/s41467-024-50428-4] [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: 09/04/2023] [Accepted: 07/09/2024] [Indexed: 07/19/2024] Open
Abstract
RNA helicase DHX9 is essential for genome stability by resolving aberrant R-loops. However, its regulatory mechanisms remain unclear. Here we show that SUMOylation at lysine 120 (K120) is crucial for DHX9 function. Preventing SUMOylation at K120 leads to R-loop dysregulation, increased DNA damage, and cell death. Cells expressing DHX9 K120R mutant which cannot be SUMOylated are more sensitive to genotoxic agents and this sensitivity is mitigated by RNase H overexpression. Unlike the mutant, wild-type DHX9 interacts with R-loop-associated proteins such as PARP1 and DDX21 via SUMO-interacting motifs. Fusion of SUMO2 to the DHX9 K120R mutant enhances its association with these proteins, reduces R-loop accumulation, and alleviates survival defects of DHX9 K120R. Our findings highlight the critical role of DHX9 SUMOylation in maintaining genome stability by regulating protein interactions necessary for R-loop balance.
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Affiliation(s)
- Bing-Ze Yang
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | - Mei-Yin Liu
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | - Kuan-Lin Chiu
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, 106319, Taiwan
| | - Yuh-Ling Chien
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | - Ching-An Cheng
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | - Yu-Lin Chen
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | - Li-Yu Tsui
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | - Keng-Ru Lin
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
| | | | - Ching-Shyi Peter Wu
- Department and Graduate Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan.
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Jin T, Yang L, Chang C, Luo H, Wang R, Gan Y, Sun Y, Guo Y, Tang R, Chen S, Meng D, Dai P, Liu M. HnRNPA2B1 ISGylation Regulates m6A-Tagged mRNA Selective Export via ALYREF/NXF1 Complex to Foster Breast Cancer Development. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307639. [PMID: 38626369 PMCID: PMC11200088 DOI: 10.1002/advs.202307639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/07/2024] [Indexed: 04/18/2024]
Abstract
Regulating nuclear export precisely is essential for maintaining mRNA homeostasis and impacts tumor progression. However, the mechanisms governing nuclear mRNA export remain poorly elucidated. Herein, it is revealed that the enhanced hypoxic long no-ncoding RNA (lncRNA prostate cancer associated transcript 6 (PCAT6) in breast cancer (BC) promotes the nuclear export of m6A-modified mRNAs, bolstering breast cancer stem cells (BCSCs) stemness and doxorubicin resistance. Clinically, hypoxic PCAT6 correlates with malignant BC features and poor prognosis. Mechanically, PCAT6 functions as a scaffold between interferon-stimulated gene 15 (ISG15) and heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2B1), leading to ISGylation of hnRNPA2B1, thus protecting hnRNPA2B1 from ubiquitination-mediated proteasomal degradation. Interestingly, as an m6A reader, hnRNPA2B1 selectively mediates m6A-tagged mRNAs nuclear export via the Aly/REF export factor (ALYREF)/ nuclear RNA export factor 1 (NXF1) complex, which promotes stemness-related genes expression. HnRNPA2B1 knockdown or mRNA export inhibition can result in the retention of nuclear m6A-tagged mRNA associated with stemness maintenance, which suppresses BCSCs self-renewal and effectively improves the efficacy of doxorubicin therapy. These findings demonstrate the pivotal role of m6A-modified mRNA nuclear export in BC progression, highlighting that the inhibition of m6A-tagged mRNA and its nuclear export is a potential therapeutic strategy for the amelioration of cancer chemotherapy.
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Affiliation(s)
- Ting Jin
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Liping Yang
- Department of Laboratory Medicinethe Second Affiliated Hospital of Chongqing Medical UniversityChongqing400010China
| | - Chao Chang
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Haojun Luo
- Department of Breast and Thyroid Surgerythe Second Affiliated Hospital of Chongqing Medical UniversityChongqing400010China
| | - Rui Wang
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Yubi Gan
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Yan Sun
- Department of Cell Biology and Medical Genetics, Basic Medical SchoolChongqing Medical UniversityChongqing400016China
| | - Yuetong Guo
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Rui Tang
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Shanchun Chen
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Die Meng
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Peijin Dai
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
| | - Manran Liu
- Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of EducationChongqing Medical UniversityChongqing400016China
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First person – Poulomi Banerjee. J Cell Sci 2022. [DOI: 10.1242/jcs.259867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Poulomi Banerjee is first author on ‘ SUMOylation modulates the function of DDX19 in mRNA export’, published in JCS. Poulomi is a PhD student in the lab of Dr Jomon Joseph at National Centre for Cell Science, NCCS Complex, Maharashtra, India, where she is interested in delineating the molecular mechanisms involved in regulation of eukaryotic gene expression in health and diseases.
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