Complex protein-DNA dynamics at the latent origin of DNA replication of Epstein-Barr virus Academic Article uri icon

Overview

MeSH Major

  • Chromatin
  • DNA-Binding Proteins
  • Epstein-Barr Virus Nuclear Antigens
  • Herpesvirus 4, Human

abstract

  • The sequential binding of the origin recognition complex (ORC), Cdc6p and the minichromosome maintenance proteins (MCM2-7) mediates replication competence at eukaryotic origins of DNA replication. The latent origin of Epstein-Barr virus, oriP, is a viral origin known to recruit ORC. OriP also binds EBNA1, a virally encoded protein that lacks any activity predicted to be required for replication initiation. Here, we used chromatin immunoprecipitation and chromatin binding to compare the cell-cycle-dependent binding of pre-RC components and EBNA1 to oriP and to global cellular chromatin. Prereplicative-complex components such as the Mcm2p-Mcm7p proteins and HsOrc1p are regulated in a cell-cycle-dependent fashion, whereas other HsOrc subunits and EBNA1 remain constantly bound. In addition, HsOrc1p becomes sensitive to the 26S proteasome after release from DNA during S phase. These results show that the complex protein-DNA dynamics at the viral oriP are synchronized with the cell division cycle. Chromatin-binding and chromatin-immunoprecipitation experiments on G0 arrested cells indicated that the ORC core complex (ORC2-5) and EBNA1 remain bound to chromatin and oriP. HsOrc6p and the MCM2-7 complex are released in resting cells. HsOrc1p is partly liberated from chromatin. Our data suggest that origins remain marked in resting cells by the ORC core complex to ensure a rapid and regulated reentry into the cell cycle. These findings indicate that HsOrc is a dynamic complex and that its DNA binding activity is regulated differently in the various stages of the cell cycle.

publication date

  • October 2003

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1242/jcs.00708

PubMed ID

  • 12953058

Additional Document Info

start page

  • 3971

end page

  • 84

volume

  • 116

number

  • 19