Format

Send to

Choose Destination
EMBO J. 1996 Feb 15;15(4):861-72.

Fission yeast cdc21, a member of the MCM protein family, is required for onset of S phase and is located in the nucleus throughout the cell cycle.

Author information

1
Department of Zoology, University of Oxford, UK.

Abstract

The fission yeast cdc21 protein belongs to the MCM family, implicated in the once per cell cycle regulation of chromosome replication. In budding yeast, proteins in this family are eliminated from the nucleus during S phase, which has led to the suggestion that they may serve to distinguish unreplicated from replicated DNA, as in the licensing factor model. We show here that, in contrast to the situation in budding yeast, cdc21 remains in the nucleus after S phase, as is found for related proteins in mammalian cells. We suggest that regulation of nuclear import of these proteins may not be an essential aspect of their function in chromosome replication. To determine the function of cdc21+, we have analysed the phenotype of a gene deletion. cdc21+ is required for entry into S phase and, unexpectedly, a proportion of cells depleted of the gene product are able to enter mitosis in the absence of DNA replication. These results are consistent with the view that individual proteins in the MCM family are required for all initiation events, and defective initiation may impair the coordination between mitosis and S phase.

PMID:
8631307
PMCID:
PMC450284
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center