Genetics. Published Articles Ahead of Print: August 20, 2008, Copyright © 2008
doi:10.1534/genetics.108.092288


A more recent version of this article appeared on September 1, 2008.

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Sister Chromatid Cohesion Role for CDC28-CDK in Saccharomyces cerevisiae

Alex Brands 1 and Robert V. Skibbens 1*

1 Lehigh University

* To whom correspondence should be addressed. E-mail: rvs3{at}lehigh.edu.

Submitted on June 5, 2008
Revised on June 22, 2008
Accepted on 22 June 2008


Abstract

High fidelity chromosome segregation requires that the sister chromatids produced during S-phase also become paired during S-phase. Ctf7p (Eco1p) is required to establish sister chromatid pairing specifically during DNA replication. However, Ctf7p also becomes active during G2/M in response to DNA damage. Ctf7p is a phosphoprotein and an in vitro target of Cdc28p cyclin-dependent kinase (CDK), suggesting one possible mechanism for regulating the essential function of Ctf7p. Here, we report a novel synthetic lethal interaction between ctf7 and cdc28. However, neither elevated CDC28 levels nor CDC28 Cak1p-bypass alleles rescue ctf7 cell phenotypes. Moreover, cells expressing Ctf7p mutated at all full and partial consensus CDK-phosphorylation sites exhibit robust cell growth. These and other results reveal that Ctf7p regulation is more complicated than previously envisioned and suggest that CDK acts in sister chromatid cohesion in parallel to Ctf7p reactions.

Key Words: CDC28, CTF7/ECO1, Cyclin-dependent kinase (CDK), cell cycle progression, sister chromatid cohesion