Characterization of the Cdc14 phosphatase activity and regulation in budding yeast
Abstract
An association with the protein Net1 controls Cdc14 regulation in budding yeast. Net1 is a competitive inhibitor of Cdc14 activity that sequesters the phosphatase in the nucleolus until anaphase. At anaphase the phosphatase is released to promote inactivation of the mitotic cyclin dependent kinase (Cdk1) and to reverse phosphorylation previously enacted by the kinase. A detailed understanding of how Net1 interacts with Cdc14 is not known. Furthermore, the full extent of Cdc14’s ability to antagonize Cdk1 has not been investigated. We demonstrate in this report that Net1 utilizes at least two regions for interacting with Cdc14, one that primarily contributes to inhibiting Cdc14 and another that is a conserved Cdc14 binding motif. Furthermore, we show that the interaction involves a region of Cdc14 distant from the active site suggesting a nontraditional mode of competitive inhibition. Lastly, we show that activated Cdc14 specifically targets proline-directed Ser sites, as opposed to Thr or Tyr, suggesting Cdc14 can only reverse a subset of the phosphorylation events performed by Cdk1.
Degree
Ph.D.
Advisors
Charbonneau, Purdue University.
Subject Area
Biochemistry
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.