Functions of fission yeast orp2 in DNA replication and checkpoint control.

Journal Article (Journal Article)

orp2 is an essential gene of the fission yeast Schizosaccharomyces pombe with 22% identity to budding yeast ORC2. We isolated temperature-sensitive alleles of orp2 using a novel plasmid shuffle based on selection against thymidine kinase. Cells bearing the temperature-sensitive allele orp2-2 fail to complete DNA replication at a restrictive temperature and undergo cell cycle arrest. Cell cycle arrest depends on the checkpoint genes rad1 and rad3. Even when checkpoint functions are wild type, the orp2-2 mutation causes high rates of chromosome and plasmid loss. These phenotypes support the idea that Orp2 is a replication initiation factor. Selective spore germination allowed analysis of orp2 deletion mutants. These experiments showed that in the absence of orp2 function, cells proceed into mitosis despite a lack of DNA replication. This suggests either that the Orp2 protein is a part of the checkpoint machinery or more likely that DNA replication initiation is required to induce the replication checkpoint signal.

Full Text

Duke Authors

Cited Authors

  • Kiely, J; Haase, SB; Russell, P; Leatherwood, J

Published Date

  • February 2000

Published In

Volume / Issue

  • 154 / 2

Start / End Page

  • 599 - 607

PubMed ID

  • 10655214

Pubmed Central ID

  • PMC1460931

Electronic International Standard Serial Number (EISSN)

  • 1943-2631

International Standard Serial Number (ISSN)

  • 0016-6731

Digital Object Identifier (DOI)

  • 10.1093/genetics/154.2.599


  • eng