Characterization of an S-Phase Specific BRCA1-Containing Complex
Abstract
The BRCA1 protein participates in multiple cellular processes, and we resolved four BRCA1-containing complexes. One of these complexes observed after treating with hydroxyurea, the HUIC (hydroxyurea induced complex) is involved with DNA damage. Following HU treatment, BRCA1 content decreased in the holo-pol (RNA polymerase II holoenzyme) and in the large complex we refer to as the Fraction 5 complex, and BRCA1 was redistributed to the HUIC. By overexpressing epitope-tagged BRCA1, full-length and deletion mutants, we characterized BRCA1 association with these complexes. We found that BARD1 is an integral holo-pol component and that the BARD1 binding domain in the BRCA1 amino-terminus is important for BRCA1 association with the holo-pol. The carboxy-terminus of BRCA1 is important for association with holo-pol, but deletion of the BRCA1 carboxy terminus resulted in low Pol II content and the absence of Pol II from the holo-pol. The HUIC was shown not to contain a number of holo-pol components, but is associated with BARD1. In a separate chromatographic fraction, BRCA1 was found associated with the Rad50/Mrell/Nbs1 complex. These data suggest that BRCA1 participates in multiple cellular processes by multiple protein complexes and that the BRCA1 content of these complexes is altered following DNA damage.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2001
- Accession Number
- ADA396679
Entities
People
- Jeffrey Parvin
- Natsuko Chiba
Organizations
- Brigham and Women's Hospital