Translesion synthesis (TLS) DNA polymerases were originally described as error-prone enzymes involved in the bypass of DNA lesions. However, extensive research over the past few decades has revealed that these enzymes play pivotal roles not only in lesion bypass, but also in a myriad of other cellular processes. Such processes include DNA replication, DNA repair, epigenetics, immune signaling, and even viral infection. This review discusses the wide range of functions exhibited by TLS polymerases, including their underlying biochemical mechanisms and associated mutagenicity. Given their multitasking ability to alleviate replication stress, TLS polymerases represent a cellular dependency and a critical vulnerability of cancer cells. Hence, this review also highlights current and emerging strategies for targeting TLS polymerases in cancer therapy.
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http://dx.doi.org/10.1016/j.molcel.2023.07.008 | DOI Listing |
bioRxiv
January 2025
Graduate Program in Molecular Medicine, University of Arizona, Tucson, Arizona, USA.
DNA viruses at once elicit and commandeer host pathways, including DNA repair pathways for virus replication. Despite encoding its own DNA polymerase and processivity factor, human cytomegalovirus (HCMV) recruits the cellular processivity factor, proliferating cell nuclear antigen (PCNA) and specialized host DNA polymerases involved in translesion synthesis (TLS) to replication compartments (RCs) where viral DNA (vDNA) is synthesized. While the recruitment of TLS polymerases is important for viral genome stability, the role of PCNA is poorly understood.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 44919, Republic of Korea.
In a comprehensive study to decipher the multi-layered response to the chemotherapeutic agent temozolomide (TMZ), we analyzed 427 genomes and determined mutational patterns in a collection of ∼40 isogenic DNA repair-deficient human TK6 lymphoblast cell lines. We first demonstrate that the spontaneous mutational background is very similar to the aging-associated mutational signature SBS40 and mainly caused by polymerase zeta-mediated translesion synthesis (TLS). MSH2-/- mismatch repair (MMR) knockout in conjunction with additional repair deficiencies uncovers cryptic mutational patterns.
View Article and Find Full Text PDFHum Reprod Open
October 2024
Universitat Rovira i Virgili, Departament de Bioquímica i Biotecnologia, Alimentació, Nutrició, Desenvolupament i Salut Mental (ANUT-DSM), Unitat de Nutrició Humana, Reus, Spain.
Oncogene
January 2025
Dept. of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, 7610001, Israel.
Hypoxia is common in tumors and is associated with cancer progression and drug resistance, driven, at least in part, by genetic instability. Little is known on how hypoxia affects Translesion DNA Synthesis (TLS), in which error-prone DNA polymerases bypass lesions, thereby maintaining DNA continuity at the price of increased mutations. Here we show that under acute hypoxia, PCNA monoubiquitination, a key step in TLS, and expression of error-prone DNA polymerases increased under regulation of the HIF1α transcription factor.
View Article and Find Full Text PDFGenes (Basel)
September 2024
DNA Damage Response Laboratory, Centre for Chromosome Biology, School of Biological and Chemical Sciences, University of Galway, Galway H91W2TY, Ireland.
DNA damage tolerance pathways that allow for the completion of replication following fork arrest are critical in maintaining genome stability during cell division. The main DNA damage tolerance pathways include strand switching, replication fork reversal and translesion synthesis (TLS). The TLS pathway is mediated by specialised DNA polymerases that can accommodate altered DNA structures during DNA synthesis, and are important in allowing replication to proceed after fork arrest, preventing fork collapse that can generate more deleterious double-strand breaks in the genome.
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