The BRCA1-associated protein BACH1 is a DNA helicase targeted by clinically relevant inactivating mutations.
BACH1 is a nuclear protein that directly interacts with the highly conserved, C-terminal BRCT repeats of the tumor suppressor, BRCA1. Mutations within the BRCT repeats disrupt the interaction between BRCA1 and BACH1, lead to defects in DNA repair, and result in breast and ovarian cancer. BACH1 is necessary for efficient double-strand break repair in a manner that depends on its association with BRCA1. Moreover, some women with early-onset breast cancer and no abnormalities in either BRCA1 or BRCA2 carry germline BACH1 coding sequence changes, suggesting that abnormal BACH1 function contributes to tumor induction. Here, we show that BACH1 is both a DNA-dependent ATPase and a 5'-to-3' DNA helicase. In two patients with early-onset breast cancer who carry distinct germline BACH1 coding sequence changes, the resulting proteins are defective in helicase activity, indicating that these sequence changes disrupt protein function. These results reinforce the notion that mutant BACH1 participates in breast cancer development.
Cantor
Sharon
S
Department of Cancer Biology, University of Massachusetts Medical School, Lazare Research Building, Worcester, MA 01605, USA.
Drapkin
Ronny
R
Zhang
Fan
F
Lin
Yafang
Y
Han
Juliana
J
Pamidi
Sushmita
S
Livingston
David M
DM
D000251:Adenosine Triphosphatases / Q000378:metabolism; D019943:Amino Acid Substitution; D019313:BRCA1 Protein / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors; D004265:DNA Helicases / Q000378:metabolism*; D051856:Fanconi Anemia Complementation Group Proteins; D018095:Germ-Line Mutation; D006801:Humans; D016350:Leucine Zippers; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
C102108:BACH1 protein, human; D019313:BRCA1 Protein; D050976:Basic-Leucine Zipper Transcription Factors; D051856:Fanconi Anemia Complementation Group Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D000251:Adenosine Triphosphatases; D004265:DNA Helicases