title: Phosphorylation of the C subunit (p66) of human DNA polymerase delta.
abstract: Of the four subunits constituting DNA polymerase delta, subunit C or p66 has been shown to mainly mediate polymerase interaction with PCNA, an auxiliary factor that greatly enhances DNA polymerase delta processivity on primed DNA templates. Here, we provide evidence that a highly conserved region located between amino acids 384 and 399 in the C-terminus of p66 is phosphorylated, most probably by Protein kinase CK2, and that another region, most probably located within the PCNA interacting domain in its extreme C-terminus, regulates its interaction with PCNA. Phosphorylation of p66 is associated with its co-localization with large subunit of DNA polymerase delta, p125, and PCNA, to the insoluble chromatin fraction at the beginning of S-phase. Taken together, the results provide evidence that concurrent phosphorylation events in p66 may positively and negatively regulate its activity and interactions with other components of the replisome during the cell cycle.
authors.affiliation: Institut Curie-CNRS, Unité de Genotoxicologie et Cycle Cellulaire, Université Paris Sud-XI, Batiment 110, 91405 Orsay Cedex, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Lemmens
authors.forename: Serge
authors.initials: S
authors.lastname: Urbach
authors.forename: Renaud
authors.initials: R
authors.lastname: Prudent
authors.forename: Claude
authors.initials: C
authors.lastname: Cochet
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Baldacci
authors.forename: Patrick
authors.initials: P
authors.lastname: Hughes
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004258:DNA Polymerase III / Q000737:chemistry* / Q000378:metabolism*; D004789:Enzyme Activation; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D011485:Protein Binding; D021122:Protein Subunits
chemical_list: D021122:Protein Subunits; D004247:DNA; D004258:DNA Polymerase III