title: A novel interaction [corrected] of nucleolin with Rad51.
abstract: Nucleolin associates with various DNA repair, recombination, and replication proteins, and possesses DNA helicase, strand annealing, and strand pairing activities. Examination of nuclear protein extracts from human somatic cells revealed that nucleolin and Rad51 co-immunoprecipitate. Furthermore, purified recombinant Rad51 associates with in vitro transcribed and translated nucleolin. Electroporation-mediated introduction of anti-nucleolin antibody resulted in a 10- to 20-fold reduction in intra-plasmid homologous recombination activity in human fibrosarcoma cells. Additionally, introduction of anti-nucleolin antibody sensitized cells to death induced by the topoisomerase II inhibitor, amsacrine. Introduction of anti-Rad51 antibody also reduced intra-plasmid homologous recombination activity and induced hypersensitivity to amsacrine-induced cell death. Co-introduction of anti-nucleolin and anti-Rad51 antibodies did not produce additive effects on homologous recombination or on cellular sensitivity to amsacrine. The association of the two proteins raises the intriguing possibility that nucleolin binding to Rad51 may function to regulate homologous recombinational repair of chromosomal DNA.
authors.affiliation: Department of Pharmacology, The University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: Ananya
authors.initials: A
authors.lastname: De
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Donahue
authors.forename: Azah
authors.initials: A
authors.lastname: Tabah
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Castro
authors.forename: Naomi
authors.initials: N
authors.lastname: Mraz
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Cruise
authors.forename: Colin
authors.initials: C
authors.lastname: Campbell
mesh_terms: D000677:Amsacrine / Q000494:pharmacology; D000906:Antibodies / Q000494:pharmacology; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D004260:DNA Repair / Q000187:drug effects; D006801:Humans; D047468:Immunoprecipitation; D010750:Phosphoproteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051135:Rad51 Recombinase / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000097796:Nucleolin
chemical_list: D000677:Amsacrine; D000906:Antibodies; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D051135:Rad51 Recombinase; D000097796:Nucleolin