Full activation of p34CDC28 histone H1 kinase activity is unable to promote entry into mitosis in checkpoint-arrested cells of the yeast Saccharomyces cerevisiae.

Journal Article (Journal Article)

In most cells, mitosis is dependent upon completion of DNA replication. The feedback mechanisms that prevent entry into mitosis by cells with damaged or incompletely replicated DNA have been termed checkpoint controls. Studies with the fission yeast Schizosaccharomyces pombe and Xenopus egg extracts have shown that checkpoint controls prevent activation of the master regulatory protein kinase, p34cdc2, that normally triggers entry into mitosis. This is achieved through inhibitory phosphorylation of the Tyr-15 residue of p34cdc2. However, studies with the budding yeast Saccharomyces cerevisiae have shown that phosphorylation of this residue is not essential for checkpoint controls to prevent mitosis. We have investigated the basis for checkpoint controls in this organism and show that these controls can prevent entry into mitosis even in cells which have fully activated the cyclin B (Clb)-associated forms of the budding yeast homolog of p34cdc2, p34CDC28, as assayed by histone H1 kinase activity. However, the active complexes in checkpoint-arrested cells are smaller than those in cycling cells, suggesting that assembly of mitosis-inducing complexes requires additional steps following histone H1 kinase activation.

Full Text

Duke Authors

Cited Authors

  • Stueland, CS; Lew, DJ; Cismowski, MJ; Reed, SI

Published Date

  • June 1, 1993

Published In

Volume / Issue

  • 13 / 6

Start / End Page

  • 3744 - 3755

PubMed ID

  • 8388545

Pubmed Central ID

  • 8388545

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/mcb.13.6.3744


  • eng

Conference Location

  • United States