Translesion synthesis is an essential cell survival strategy to promote replication after DNA damage. The accumulation of Y family polymerases (pol) iota and Rev1 at the stalled replication machinery is mediated by the ubiquitin-binding motifs (UBMs) of the polymerases and enhanced by PCNA monoubiquitination. We report the solution structures of the C-terminal UBM of human pol iota and its complex with ubiquitin. Distinct from other ubiquitin-binding domains, the UBM binds to the hydrophobic surface of ubiquitin centered at L8. Accordingly, mutation of L8A, but not I44A, of ubiquitin abolishes UBM binding. Human pol iota contains two functional UBMs, both contributing to replication foci formation. In contrast, only the second UBM of Saccharomyces cerevisiae Rev1 binds to ubiquitin and is essential for Rev1-dependent cell survival and mutagenesis. Point mutations disrupting the UBM-ubiquitin interaction also impair the accumulation of pol iota in replication foci and Rev1-mediated DNA damage tolerance in vivo.
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http://dx.doi.org/10.1016/j.molcel.2009.12.038 | DOI Listing |
Front Pharmacol
November 2024
Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
DNA Repair (Amst)
September 2024
Laboratory of DNA Repair, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil. Electronic address:
Glioblastoma (GBM) is a highly aggressive brain tumor associated with poor patient survival. The current standard treatment involves invasive surgery, radiotherapy, and chemotherapy employing temozolomide (TMZ). Resistance to TMZ is, however, a major challenge.
View Article and Find Full Text PDFDNA Repair (Amst)
September 2024
Institute of Molecular Genetics, National Research Center "Kurchatov Institute", Moscow 123182, Russia; Institute of Gene Biology of Russian Academy of Sciences, Moscow 119334, Russia. Electronic address:
Epigenetic cytosine methylation covers most of genomic CpG dinucleotides in human cells. In addition to common deamination-mediated mutagenesis at CpG sites, an alternative deamination-independent pathway associated with DNA polymerase activity was previously described. This mutagenesis is characterized by the TCG→TTG mutational signature and is believed to arise from dAMP misincorporation opposite 5-methylcytosine (mC) or its oxidized derivative 5-hydroxymethylcytosine (hmC) by B-family replicative DNA polymerases with disrupted proofreading 3→5'-exonuclease activity.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Cell Res
June 2024
Laboratory of Mutagenesis and DNA Damage Tolerance, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland. Electronic address:
Human DNA polymerase ι (Polι) belongs to the Y-family of specialized DNA polymerases engaged in the DNA damage tolerance pathway of translesion DNA synthesis that is crucial to the maintenance of genome integrity. The extreme infidelity of Polι and the fact that both its up- and down-regulation correlate with various cancers indicate that Polι expression and access to the replication fork should be strictly controlled. Here, we identify RNF2, an E3 ubiquitin ligase, as a new interacting partner of Polι that is responsible for Polι stabilization in vivo.
View Article and Find Full Text PDFCell Death Dis
February 2024
Department of Radiation Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, P.R. China.
Esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancer types, with a low 5-year survival rate of ~20%. Our prior research has suggested that DNA Polymerase iota (Pol ι), a member of Y-family DNA polymerase, plays a crucial role in the invasion and metastasis of ESCC. However, the underlying mechanism is not well understood.
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