Redistribution of BRCA1 among Four Different Protein Complexes following Replication Blockage

Natsuko Chiba, Jeffrey D. Parvin

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


The BRCA1 protein is known to participate in multiple cellular processes. In these experiments, we resolved four distinct BRCA1-containing complexes. We found BRCA1 associated with the RNA polymerase II holoenzyme (holo-pol), a large mass complex called the fraction 5 complex, the Rad50-Mre11-Nbs1 complex, and a complex that has not been described previously. We observed this new complex after treating cells with hydroxyurea, suggesting that the hydroxyurea-induced complex (HUIC) is involved with the response to DNA replication blockage. After hydroxyurea treatment of cells, BRCA1 content decreased in the holo-pol and the fraction 5 complex, and BRCA1 was redistributed to the HUIC. The HUIC was shown not to contain a number of holo-pol components or the Rad50-Mre11-Nbs1 complex but was associated with the BRCA1-associated RING domain protein BARD1. These data suggest that BRCA1 participates in multiple cellular processes by multiple protein complexes and that the BRCA1 content of these complexes is dynamically altered after DNA replication blockage.

Original languageEnglish
Pages (from-to)38549-38554
Number of pages6
JournalJournal of Biological Chemistry
Issue number42
Publication statusPublished - 2001 Oct 19
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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