title: Posttranslational Regulation of Human DNA Polymerase ι.
abstract: Human DNA polymerases (pols) η and ι are Y-family DNA polymerase paralogs that facilitate translesion synthesis past damaged DNA. Both polη and polι can be monoubiquitinated in vivo. Polη has been shown to be ubiquitinated at one primary site. When this site is unavailable, three nearby lysines may become ubiquitinated. In contrast, mass spectrometry analysis of monoubiquitinated polι revealed that it is ubiquitinated at over 27 unique sites. Many of these sites are localized in different functional domains of the protein, including the catalytic polymerase domain, the proliferating cell nuclear antigen-interacting region, the Rev1-interacting region, and its ubiquitin binding motifs UBM1 and UBM2. Polι monoubiquitination remains unchanged after cells are exposed to DNA-damaging agents such as UV light (generating UV photoproducts), ethyl methanesulfonate (generating alkylation damage), mitomycin C (generating interstrand cross-links), or potassium bromate (generating direct oxidative DNA damage). However, when exposed to naphthoquinones, such as menadione and plumbagin, which cause indirect oxidative damage through mitochondrial dysfunction, polι becomes transiently polyubiquitinated via Lys(11)- and Lys(48)-linked chains of ubiquitin and subsequently targeted for degradation. Polyubiquitination does not occur as a direct result of the perturbation of the redox cycle as no polyubiquitination was observed after treatment with rotenone or antimycin A, which both inhibit mitochondrial electron transport. Interestingly, polyubiquitination was observed after the inhibition of the lysine acetyltransferase KATB3/p300. We hypothesize that the formation of polyubiquitination chains attached to polι occurs via the interplay between lysine acetylation and ubiquitination of ubiquitin itself at Lys(11) and Lys(48) rather than oxidative damage per se.
authors.affiliation: Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371,; Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: McIntyre
authors.affiliation: Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371.
authors.forename: Mary P
authors.initials: MP
authors.lastname: McLenigan
authors.affiliation: Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371.
authors.forename: Ekaterina G
authors.initials: EG
authors.lastname: Frank
authors.affiliation: Department of Chemistry, University of California, Riverside, California 92521-0403.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Dai
authors.affiliation: Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Chemistry, University of California, Riverside, California 92521-0403.
authors.forename: Yinsheng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-3371,. Electronic address: woodgate@nih.gov.
authors.forename: Roger
authors.initials: R
authors.lastname: Woodgate
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites / Q000235:genetics; D004249:DNA Damage; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D008239:Lysine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D054875:Ubiquitination; D000094769:DNA Polymerase iota
chemical_list: D011994:Recombinant Proteins; D004259:DNA-Directed DNA Polymerase; D008239:Lysine; D000094769:DNA Polymerase iota; C000722070:POLI protein, human
keywords: DNA polymerase ι; DNA repair; DNA synthesis; Y-family DNA polymerase; mutagenesis; posttranslational modification (PTM); ubiquitin