title: RAD51 and DMC1 form mixed complexes associated with mouse meiotic chromosome cores and synaptonemal complexes.
abstract: The eukaryotic RecA homologues RAD51 and DMC1 function in homology recognition and formation of joint-molecule recombination intermediates during yeast meiosis. The precise immunolocalization of these two proteins on the meiotic chromosomes of plants and animals has been complicated by their high degree of identity at the amino acid level. With antibodies that have been immunodepleted of cross-reactive epitopes, we demonstrate that RAD51 and DMC1 have identical distribution patterns in extracts of mouse spermatocytes in successive prophase I stages, suggesting coordinate functionality. Immunofluorescence and immunoelectron microscopy with these antibodies demonstrate colocalization of the two proteins on the meiotic chromosome cores at early prophase I. We also show that mouse RAD51 and DMC1 establish protein-protein interactions with each other and with the chromosome core component COR1(SCP3) in a two-hybrid system and in vitro binding analyses. These results suggest that the formation of a multiprotein recombination complex associated with the meiotic chromosome cores is essential for the development and fulfillment of the meiotic recombination process.
authors.affiliation: Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Tarsounas
authors.forename: T
authors.initials: T
authors.lastname: Morita
authors.forename: R E
authors.initials: RE
authors.lastname: Pearlman
authors.forename: P B
authors.initials: PB
authors.lastname: Moens
mesh_terms: D000251:Adenosine Triphosphatases; D000818:Animals; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins / Q000235:genetics*; D007150:Immunohistochemistry; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D009687:Nuclear Proteins; D028044:Phosphate-Binding Proteins; D051135:Rad51 Recombinase; D011995:Recombination, Genetic; D013090:Spermatocytes / Q000166:cytology / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C513032:Dmc1 protein, mouse; D009687:Nuclear Proteins; D028044:Phosphate-Binding Proteins; D051135:Rad51 Recombinase; C495154:Rad51 protein, mouse; D000251:Adenosine Triphosphatases