Potential role of BRCA2 in a mitotic checkpoint after phosphorylation by hBUBR1.
BRCA2, a gene responsible for inherited susceptibility to breast cancer in a number of families, is thought to be critical for replication and repair of DNA during S-phase. To elucidate the physiological functions of BRCA2, we used a yeast two-hybrid system to screen for proteins that could associate with BRCA2. Here we report interaction of BRCA2 with a mitotic checkpoint protein, hBUBR1, and its phosphorylation by hBUBR1 in vitro. After cotransfection of BRCA2 and hBUBR1 expression vectors into the COS7 cell line, both proteins were stained together in the nuclei of cells whose spindle fibers were disrupted, but not in undamaged cells. Treatment with vincristine, which disrupts microtubules, significantly increased expression of both hBUBR1 and BRCA2 in the MCF7 cells. The results suggest that BRCA2 protein might be involved in a mitotic checkpoint in vivo after it has been phosphorylated by hBUBR1.
Futamura
M
M
Laboratory of Molecular Medicine, Human Genome Center, University of Tokyo, Japan.
Arakawa
H
H
Matsuda
K
K
Katagiri
T
T
Saji
S
S
Miki
Y
Y
Nakamura
Y
Y
D000818:Animals; D024682:BRCA2 Protein; D019556:COS Cells; D018797:Cell Cycle Proteins; D005786:Gene Expression Regulation / Q000187:drug effects; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D008938:Mitosis / Q000502:physiology*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D010766:Phosphorylation; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology
D024682:BRCA2 Protein; D018797:Cell Cycle Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D014750:Vincristine; D005982:Glutathione Transferase; D011494:Protein Kinases; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases