• Register
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.


Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.


Expanded roles of the origin recognition complex in the architecture and function of silenced chromatin in Saccharomyces cerevisiae.

The silenced chromatin at the cryptic mating-type loci (HML and HMR) of Saccharomyces cerevisiae requires a cell cycle event between early S phase and G(2)/M phase to achieve repression. Although DNA replication per se is not essential for silencing, mutations in many of the proteins involved in DNA replication affect silencing. Each of the four silencers, which flank the silenced loci, includes an origin recognition complex (ORC) binding site (ACS). ORC directly interacted with Sir1 and recruits Sir1 to the silencers. This study describes additional roles for ORC in the architecture of silenced chromatin. Using chromatin immunoprecipitation (ChIP) analysis, we found that ORC physically interacts throughout the internal regions of HMR as well as with silencers. This interaction depended on the presence of Sir proteins and, in part, on the HMR-I silencer. ORC remained associated with the internal regions of HMR even when these regions were recombinationally separated from the silencers. Moreover, ORC could be recruited to the silencers lacking an ACS through its Sir1 interaction.

Pubmed ID: 19948882


  • Ozaydin B
  • Rine J


Molecular and cellular biology

Publication Data

February 15, 2010

Associated Grants

  • Agency: PHS HHS, Id: GMS 31105

Mesh Terms

  • Chromatin
  • DNA Replication
  • Gene Expression Regulation, Fungal
  • Gene Silencing
  • Genes, Mating Type, Fungal
  • Origin Recognition Complex
  • Saccharomyces cerevisiae
  • Silent Information Regulator Proteins, Saccharomyces cerevisiae