Meiotic nuclear divisions in budding yeast require PP2ACdc55-mediated antagonism of Net1 phosphorylation by Cdk

Kerr, Gary; Sarkar, Sourav; Tibbles, Katherine L.; Petronczki, Mark; Millar, Jonathan B.A.; Arumugam, Prakash

Abstract

During meiosis, one round of deoxyribonucleic acid replication is followed by two rounds of nuclear division. In Saccharomyces cerevisiae, activation of the Cdc14 early anaphase release (FEAR) network is required for exit from meiosis I but does not lead to the activation of origins of replication. The precise mechanism of how FEAR regulates meiosis is not understood. In this paper, we report that premature activation of FEAR during meiosis caused by loss of protein phosphatase PP2ACdc55 activity blocks bipolar spindle assembly and nuclear divisions. In cdc55 meiotic null (cdc55-mn) cells, the cyclin-dependent kinase (Cdk)–counteracting phosphatase Cdc14 was released prematurely from the nucleolus concomitant with hyperphosphorylation of its nucleolar anchor protein Net1. Crucially, a mutant form of Net1 that lacks six Cdk phosphorylation sites rescued the meiotic defect of cdc55-mn cells. Expression of a dominant mutant allele of CDC14 mimicked the cdc55-mn phenotype. We propose that phosphoregulation of Net1 by PP2ACdc55 is essential for preventing precocious exit from meiosis I.

• Journal Article Type: Article
• Acceptance Date: May 25, 2011
• Online Publication Date: Jun 20, 2011
• Publication Date: Jun 27, 2011
• Deposit Date: Feb 19, 2019
• Publicly Available Date: Mar 5, 2019
• Journal: Journal of Cell Biology
• Print ISSN: 0021-9525
• Publisher: Rockefeller University Press
• Peer Reviewed: Peer Reviewed
• Volume: 193
• Issue: 7
• Pages: 1157-1166
• Public URL: http://researchrepository.napier.ac.uk/Output/1596241
• Contract Date: Mar 5, 2019