{"title":"Microhomology-Mediated End-Joining Chronicles: Tracing the Evolutionary Footprints of Genome Protection.","authors":"Agnel Sfeir, Marcel Tijsterman, Mitch McVey","doi":"10.1146/annurev-cellbio-111822-014426","DOIUrl":null,"url":null,"abstract":"<p><p>The fidelity of genetic information is essential for cellular function and viability. DNA double-strand breaks (DSBs) pose a significant threat to genome integrity, necessitating efficient repair mechanisms. While the predominant repair strategies are usually accurate, paradoxically, error-prone pathways also exist. This review explores recent advances and our understanding of microhomology-mediated end joining (MMEJ), an intrinsically mutagenic DSB repair pathway conserved across organisms. Central to MMEJ is the activity of DNA polymerase theta (Polθ), a specialized polymerase that fuels MMEJ mutagenicity. We examine the molecular intricacies underlying MMEJ activity and discuss its function during mitosis, where the activity of Polθ emerges as a last-ditch effort to resolve persistent DSBs, especially when homologous recombination is compromised. We explore the promising therapeutic applications of targeting Polθ in cancer treatment and genome editing. Lastly, we discuss the evolutionary consequences of MMEJ, highlighting its delicate balance between protecting genome integrity and driving genomic diversity.</p>","PeriodicalId":7944,"journal":{"name":"Annual review of cell and developmental biology","volume":null,"pages":null},"PeriodicalIF":11.4000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annual review of cell and developmental biology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1146/annurev-cellbio-111822-014426","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/9/21 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The fidelity of genetic information is essential for cellular function and viability. DNA double-strand breaks (DSBs) pose a significant threat to genome integrity, necessitating efficient repair mechanisms. While the predominant repair strategies are usually accurate, paradoxically, error-prone pathways also exist. This review explores recent advances and our understanding of microhomology-mediated end joining (MMEJ), an intrinsically mutagenic DSB repair pathway conserved across organisms. Central to MMEJ is the activity of DNA polymerase theta (Polθ), a specialized polymerase that fuels MMEJ mutagenicity. We examine the molecular intricacies underlying MMEJ activity and discuss its function during mitosis, where the activity of Polθ emerges as a last-ditch effort to resolve persistent DSBs, especially when homologous recombination is compromised. We explore the promising therapeutic applications of targeting Polθ in cancer treatment and genome editing. Lastly, we discuss the evolutionary consequences of MMEJ, highlighting its delicate balance between protecting genome integrity and driving genomic diversity.
期刊介绍:
The Annual Review of Cell and Developmental Biology, established in 1985, comprehensively addresses major advancements in cell and developmental biology. Encompassing the structure, function, and organization of cells, as well as the development and evolution of cells in relation to both single and multicellular organisms, the journal explores models and tools of molecular biology. As of the current volume, the journal has transitioned from gated to open access through Annual Reviews' Subscribe to Open program, making all articles published under a CC BY license.