title: Human DNA polymerase epsilon colocalizes with proliferating cell nuclear antigen and DNA replication late, but not early, in S phase.
abstract: DNA polymerase epsilon (pol epsilon) has been implicated in DNA replication, DNA repair, and cell cycle control, but its precise roles are unclear. When the subcellular localization of human pol epsilon was examined by indirect immunofluorescence, pol epsilon appeared in discrete nuclear foci that colocalized with proliferating cell nuclear antigen (PCNA) foci and sites of DNA synthesis only late in S phase. Early in S phase, pol epsilon foci were adjacent to PCNA foci. In contrast to PCNA foci that were only present in S phase, pol epsilon foci were present throughout mitosis and the G(1) phase of cycling cells. It is hypothesized from these observations that pol epsilon and PCNA have separate but associated functions early in S phase and that pol epsilon participates with PCNA in DNA replication late in S phase.
authors.affiliation: Department of Molecular and Cell Biology, Division of Biochemistry and Molecular Biology, University of California, Berkeley, California 94720-3206, USA.
authors.forename: Jill
authors.initials: J
authors.lastname: Fuss
authors.forename: Stuart
authors.initials: S
authors.lastname: Linn
mesh_terms: D000963:Antimetabolites / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D004249:DNA Damage; D004257:DNA Polymerase II / Q000737:chemistry* / Q000378:metabolism*; D004260:DNA Repair; D005347:Fibroblasts / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008938:Mitosis; D008954:Models, Biological; D015739:Nocodazole / Q000494:pharmacology; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D016196:S Phase; D014466:Ultraviolet Rays
chemical_list: D000963:Antimetabolites; D000970:Antineoplastic Agents; D018809:Proliferating Cell Nuclear Antigen; D011838:Radiation-Sensitizing Agents; D004247:DNA; D004257:DNA Polymerase II; D001973:Bromodeoxyuridine; D015739:Nocodazole