{"title":"DHX36 maintains genomic integrity by unwinding G-quadruplexes","authors":"Ayaka Mizumoto, Yuta Yokoyama, Tomoichiro Miyoshi, Masahiro Takikawa, Fuyuki Ishikawa, Mahito Sadaie","doi":"10.1111/gtc.13061","DOIUrl":null,"url":null,"abstract":"<p>The guanine-rich stretch of single-stranded DNA (ssDNA) forms a G-quadruplex (G4) in a fraction of genic and intergenic chromosomal regions. The probability of G4 formation increases during events causing ssDNA generation, such as transcription and replication. In turn, G4 abrogates these events, leading to DNA damage. DHX36 unwinds G4-DNA in vitro and in human cells. However, its spatial correlation with G4-DNA in vivo and its role in genome maintenance remain unclear. Here, we demonstrate a connection between DHX36 and G4-DNA and its implications for genomic integrity. The nuclear localization of DHX36 overlapped with that of G4-DNA, RNA polymerase II, and a splicing-related factor. Depletion of DHX36 resulted in accumulated DNA damage, slower cell growth, and enhanced cell growth inhibition upon treatment with a G4-stabilizing compound; DHX36 expression reversed these defects. In contrast, the reversal upon expression of DHX36 mutants that could not bind G4 was imperfect. Thus, DHX36 may suppress DNA damage by promoting the clearance of G4-DNA for cell growth and survival. Our findings deepen the understanding of G4 resolution in the maintenance of genomic integrity.</p>","PeriodicalId":12742,"journal":{"name":"Genes to Cells","volume":null,"pages":null},"PeriodicalIF":1.3000,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gtc.13061","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Genes to Cells","FirstCategoryId":"99","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/gtc.13061","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The guanine-rich stretch of single-stranded DNA (ssDNA) forms a G-quadruplex (G4) in a fraction of genic and intergenic chromosomal regions. The probability of G4 formation increases during events causing ssDNA generation, such as transcription and replication. In turn, G4 abrogates these events, leading to DNA damage. DHX36 unwinds G4-DNA in vitro and in human cells. However, its spatial correlation with G4-DNA in vivo and its role in genome maintenance remain unclear. Here, we demonstrate a connection between DHX36 and G4-DNA and its implications for genomic integrity. The nuclear localization of DHX36 overlapped with that of G4-DNA, RNA polymerase II, and a splicing-related factor. Depletion of DHX36 resulted in accumulated DNA damage, slower cell growth, and enhanced cell growth inhibition upon treatment with a G4-stabilizing compound; DHX36 expression reversed these defects. In contrast, the reversal upon expression of DHX36 mutants that could not bind G4 was imperfect. Thus, DHX36 may suppress DNA damage by promoting the clearance of G4-DNA for cell growth and survival. Our findings deepen the understanding of G4 resolution in the maintenance of genomic integrity.
期刊介绍:
Genes to Cells provides an international forum for the publication of papers describing important aspects of molecular and cellular biology. The journal aims to present papers that provide conceptual advance in the relevant field. Particular emphasis will be placed on work aimed at understanding the basic mechanisms underlying biological events.