title: Cell cycle-dependent protein expression of mammalian homologs of yeast DNA double-strand break repair genes Rad51 and Rad52.
abstract: Recently, human and rodent homologs of yeast repair genes Rad51 and Rad52 have been identified and proposed to play roles in DNA double-strand break (DSB) repair. In this study, cell cycle-dependent expression of human and rodent RAD51 and RAD52 proteins was monitored using two approaches. First, flow cytometric measurements of DNA content and immunofluorescence were used to determine the phase-specific levels of RAD51 and RAD52 protein expression in irradiated and control populations. The expression of both proteins was lowest in G0/G1, increased in S and reached a maximum in G2/M. No difference was found in the whole-cell level of RAD51 or RAD52 protein expression between gamma-irradiated and control cell populations. Second, cell cycle-dependent protein expression was confirmed by Western analysis of populations synchronized in G0, G1 and G2 phases. Analysis of V3, a hamster equivalent of SCID, indicates that the protein level increases of RAD51 and RAD52 from G0 to G1/S/G2 do not require DNA-PK.
authors.affiliation: Life Sciences Division, Los Alamos National Laboratory, NM 87545, USA.
authors.forename: F
authors.initials: F
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Nastasi
authors.forename: Z
authors.initials: Z
authors.lastname: Shen
authors.forename: M
authors.initials: M
authors.lastname: Brenneman
authors.forename: H
authors.initials: H
authors.lastname: Crissman
authors.forename: D J
authors.initials: DJ
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002453:Cell Cycle / Q000235:genetics* / Q000528:radiation effects; D002478:Cells, Cultured; D002588:Cesium Radioisotopes; D006224:Cricetinae; D004260:DNA Repair / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000528:radiation effects; D005347:Fibroblasts; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000528:radiation effects; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D008969:Molecular Sequence Data; D051135:Rad51 Recombinase; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D012867:Skin
chemical_list: D002588:Cesium Radioisotopes; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C495151:RAD51 protein, S cerevisiae; C495153:RAD51 protein, human; D051135:Rad51 Recombinase