title: Requirement of proliferating cell nuclear antigen in RAD6-dependent postreplicational DNA repair.
abstract: The proliferating cell nuclear antigen (PCNA) acts as a processivity factor for replicative DNA polymerases and is essential for DNA replication. In vitro studies have suggested a role for PCNA-in the repair synthesis step of nucleotide excision repair, and PCNA interacts with the cyclin-dependent kinase inhibitor p21. However, because of the lack of genetic evidence, it is not clear which of the DNA repair processes are in fact affected by PCNA in vivo. Here, we describe a PCNA mutation, pol30-46, that confers ultraviolet (UV) sensitivity but has no effect on growth or cell cycle progression, and the mutant pcna interacts normally with DNA polymerase delta and epsilon. Genetic studies indicate that the pol30-46 mutation is specifically defective in RAD6-dependent postreplicational repair of UV damaged DNA, and this mutation impairs the error-free mode of bypass repair. These results implicate a role for PCNA as an intermediary between DNA replication and postreplicational DNA repair.
authors.affiliation: Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston 77555-1061, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Torres-Ramos
authors.forename: B L
authors.initials: BL
authors.lastname: Yoder
authors.forename: P M
authors.initials: PM
authors.lastname: Burgers
authors.forename: S
authors.initials: S
authors.lastname: Prakash
authors.forename: L
authors.initials: L
authors.lastname: Prakash
mesh_terms: D002499:Centrifugation, Density Gradient; D004260:DNA Repair; D004261:DNA Replication; D004843:Epistasis, Genetic; D016195:G2 Phase; D008025:Ligases / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D010957:Plasmids / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000502:physiology*; D011836:Radiation Tolerance; D016196:S Phase; D044763:Ubiquitin-Conjugating Enzymes; D014466:Ultraviolet Rays
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D044763:Ubiquitin-Conjugating Enzymes; D008025:Ligases