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Park J, Desai H, Liboy-Lugo JM, Gu S, Jowhar Z, Xu A, Floor SN. IGHMBP2 deletion suppresses translation and activates the integrated stress response. Life Sci Alliance 2024; 7:e202302554. [PMID: 38803225 PMCID: PMC11109757 DOI: 10.26508/lsa.202302554] [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: 12/22/2023] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/29/2024] Open
Abstract
IGHMBP2 is a nonessential, superfamily 1 DNA/RNA helicase that is mutated in patients with rare neuromuscular diseases SMARD1 and CMT2S. IGHMBP2 is implicated in translational and transcriptional regulation via biochemical association with ribosomal proteins, pre-rRNA processing factors, and tRNA-related species. To uncover the cellular consequences of perturbing IGHMBP2, we generated full and partial IGHMBP2 deletion K562 cell lines. Using polysome profiling and a nascent protein synthesis assay, we found that IGHMBP2 deletion modestly reduces global translation. We performed Ribo-seq and RNA-seq and identified diverse gene expression changes due to IGHMBP2 deletion, including ATF4 up-regulation. With recent studies showing the integrated stress response (ISR) can contribute to tRNA metabolism-linked neuropathies, we asked whether perturbing IGHMBP2 promotes ISR activation. We generated ATF4 reporter cell lines and found IGHMBP2 knockout cells demonstrate basal, chronic ISR activation. Our work expands upon the impact of IGHMBP2 in translation and elucidates molecular mechanisms that may link mutant IGHMBP2 to severe clinical phenotypes.
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Affiliation(s)
- Jesslyn Park
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Hetvee Desai
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
| | - José M Liboy-Lugo
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Sohyun Gu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Ziad Jowhar
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Albert Xu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
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Park JE, Desai H, Liboy-Lugo J, Gu S, Jowhar Z, Xu A, Floor SN. IGHMBP2 deletion suppresses translation and activates the integrated stress response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.11.571166. [PMID: 38168189 PMCID: PMC10760061 DOI: 10.1101/2023.12.11.571166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
IGHMBP2 is a non-essential, superfamily 1 DNA/RNA helicase that is mutated in patients with rare neuromuscular diseases SMARD1 and CMT2S. IGHMBP2 is implicated in translational and transcriptional regulation via biochemical association with ribosomal proteins, pre-rRNA processing factors, and tRNA-related species. To uncover the cellular consequences of perturbing IGHMBP2, we generated full and partial IGHMBP2 deletion K562 cell lines. Using polysome profiling and a nascent protein synthesis assay, we found that IGHMBP2 deletion modestly reduces global translation. We performed Ribo-seq and RNA-seq and identified diverse gene expression changes due to IGHMBP2 deletion, including ATF4 upregulation. With recent studies showing the ISR can contribute to tRNA metabolism-linked neuropathies, we asked whether perturbing IGHMBP2 promotes ISR activation. We generated ATF4 reporter cell lines and found IGHMBP2 knockout cells demonstrate basal, chronic ISR activation. Our work expands upon the impact of IGHMBP2 in translation and elucidates molecular mechanisms that may link mutant IGHMBP2 to severe clinical phenotypes.
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Affiliation(s)
- Jesslyn E. Park
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Hetvee Desai
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
| | - José Liboy-Lugo
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Sohyun Gu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Ziad Jowhar
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Albert Xu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, California, USA, 94143
| | - Stephen N. Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, USA, 94143
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California, USA, 94143
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