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Subramani PG, Fraszczak J, Helness A, Estall JL, Möröy T, Di Noia JM. Conserved role of hnRNPL in alternative splicing of epigenetic modifiers enables B cell activation. EMBO Rep 2024; 25:2662-2697. [PMID: 38744970 PMCID: PMC11169469 DOI: 10.1038/s44319-024-00152-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
The multifunctional RNA-binding protein hnRNPL is implicated in antibody class switching but its broader function in B cells is unknown. Here, we show that hnRNPL is essential for B cell activation, germinal center formation, and antibody responses. Upon activation, hnRNPL-deficient B cells show proliferation defects and increased apoptosis. Comparative analysis of RNA-seq data from activated B cells and another eight hnRNPL-depleted cell types reveals common effects on MYC and E2F transcriptional programs required for proliferation. Notably, while individual gene expression changes are cell type specific, several alternative splicing events affecting histone modifiers like KDM6A and SIRT1, are conserved across cell types. Moreover, hnRNPL-deficient B cells show global changes in H3K27me3 and H3K9ac. Epigenetic dysregulation after hnRNPL loss could underlie differential gene expression and upregulation of lncRNAs, and explain common and cell type-specific phenotypes, such as dysfunctional mitochondria and ROS overproduction in mouse B cells. Thus, hnRNPL is essential for the resting-to-activated B cell transition by regulating transcriptional programs and metabolism, at least in part through the alternative splicing of several histone modifiers.
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Affiliation(s)
- Poorani Ganesh Subramani
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada
| | - Jennifer Fraszczak
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Anne Helness
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Jennifer L Estall
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada
- Molecular Biology Programs, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
- Department of Medicine, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
| | - Tarik Möröy
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada
- Molecular Biology Programs, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, 2900 Boul Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Javier M Di Noia
- Institut de Recherches Cliniques de Montréal, 110 avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.
- Department of Medicine, Division of Experimental Medicine, McGill University, 1001 Boulevard Decarie, Montreal, QC, H4A 3J1, Canada.
- Molecular Biology Programs, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada.
- Department of Medicine, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada.
- Département de microbiologie, infectiologie et immunologie, Université de Montréal, 2900 Boul Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
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Tao Y, Zhang Q, Wang H, Yang X, Mu H. Alternative splicing and related RNA binding proteins in human health and disease. Signal Transduct Target Ther 2024; 9:26. [PMID: 38302461 PMCID: PMC10835012 DOI: 10.1038/s41392-024-01734-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 12/18/2023] [Accepted: 12/27/2023] [Indexed: 02/03/2024] Open
Abstract
Alternative splicing (AS) serves as a pivotal mechanism in transcriptional regulation, engendering transcript diversity, and modifications in protein structure and functionality. Across varying tissues, developmental stages, or under specific conditions, AS gives rise to distinct splice isoforms. This implies that these isoforms possess unique temporal and spatial roles, thereby associating AS with standard biological activities and diseases. Among these, AS-related RNA-binding proteins (RBPs) play an instrumental role in regulating alternative splicing events. Under physiological conditions, the diversity of proteins mediated by AS influences the structure, function, interaction, and localization of proteins, thereby participating in the differentiation and development of an array of tissues and organs. Under pathological conditions, alterations in AS are linked with various diseases, particularly cancer. These changes can lead to modifications in gene splicing patterns, culminating in changes or loss of protein functionality. For instance, in cancer, abnormalities in AS and RBPs may result in aberrant expression of cancer-associated genes, thereby promoting the onset and progression of tumors. AS and RBPs are also associated with numerous neurodegenerative diseases and autoimmune diseases. Consequently, the study of AS across different tissues holds significant value. This review provides a detailed account of the recent advancements in the study of alternative splicing and AS-related RNA-binding proteins in tissue development and diseases, which aids in deepening the understanding of gene expression complexity and offers new insights and methodologies for precision medicine.
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Affiliation(s)
- Yining Tao
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
- Shanghai Bone Tumor Institution, 200000, Shanghai, China
| | - Qi Zhang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
| | - Haoyu Wang
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
- Shanghai Bone Tumor Institution, 200000, Shanghai, China
| | - Xiyu Yang
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
- Shanghai Bone Tumor Institution, 200000, Shanghai, China
| | - Haoran Mu
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China.
- Shanghai Bone Tumor Institution, 200000, Shanghai, China.
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Tompkins VS, Xue Z, Peterson JM, Rouse WB, O’Leary CA, Moss WN. Identification of MYC intron 2 regions that modulate expression. PLoS One 2024; 19:e0296889. [PMID: 38236931 PMCID: PMC10795982 DOI: 10.1371/journal.pone.0296889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 12/19/2023] [Indexed: 01/22/2024] Open
Abstract
MYC pre-mRNA is spliced with high fidelity to produce the transcription factor known to regulate cellular differentiation, proliferation, apoptosis, and alternative splicing. The mechanisms underpinning the pre-mRNA splicing of MYC, however, remain mostly unexplored. In this study, we examined the interaction of heterogeneous nuclear ribonucleoprotein C (HNRNPC) with MYC intron 2. Building off published eCLIP studies, we confirmed this interaction with poly(U) regions in intron 2 of MYC and found that full binding is correlated with optimal protein production. The interaction appears to be compensatory, as mutational disruption of all three poly(U) regions was required to reduce both HNRNPC binding capacity and fidelity of either splicing or translation. Poly(U) sequences in MYC intron 2 were relatively conserved across sequences from several different species. Lastly, we identified a short sequence just upstream of an HNRNPC binding region that when removed enhances MYC translation.
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Affiliation(s)
- Van S. Tompkins
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Zheng Xue
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Jake M. Peterson
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Warren B. Rouse
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Collin A. O’Leary
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Walter N. Moss
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
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Wang Y, Liu J, Zhou F. The role of TIA1 and TIAL1 in germinal center B cell function and survival. Cell Mol Immunol 2023; 20:1090-1092. [PMID: 37626212 PMCID: PMC10468532 DOI: 10.1038/s41423-023-01067-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 08/27/2023] Open
Affiliation(s)
- Yongqiang Wang
- Department of Otolaryngology Head and Neck Surgery, The First Affiliated Hospital of Soochow University, Suzhou, 215123, China
- Institutes of Biology and Medical Science, Soochow University, Suzhou, 215123, China
| | - Jisheng Liu
- Department of Otolaryngology Head and Neck Surgery, The First Affiliated Hospital of Soochow University, Suzhou, 215123, China.
| | - Fangfang Zhou
- Institutes of Biology and Medical Science, Soochow University, Suzhou, 215123, China.
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