title: PP2A(Cdc55)'s role in reductional chromosome segregation during achiasmate meiosis in budding yeast is independent of its FEAR function.
abstract: PP2A(Cdc55) is a highly conserved serine-threonine protein phosphatase that is involved in diverse cellular processes. In budding yeast, meiotic cells lacking PP2A(Cdc55) activity undergo a premature exit from meiosis I which results in a failure to form bipolar spindles and divide nuclei. This defect is largely due to its role in negatively regulating the Cdc Fourteen Early Anaphase Release (FEAR) pathway. PP2A(Cdc55) prevents nucleolar release of the Cdk (Cyclin-dependent kinase)-antagonising phosphatase Cdc14 by counteracting phosphorylation of the nucleolar protein Net1 by Cdk. CDC55 was identified in a genetic screen for monopolins performed by isolating suppressors of spo11Δ spo12Δ lethality suggesting that Cdc55 might have a role in meiotic chromosome segregation. We investigated this possibility by isolating cdc55 alleles that suppress spo11Δ spo12Δ lethality and show that this suppression is independent of PP2A(Cdc55)'s FEAR function. Although the suppressor mutations in cdc55 affect reductional chromosome segregation in the absence of recombination, they have no effect on chromosome segregation during wild type meiosis. We suggest that Cdc55 is required for reductional chromosome segregation during achiasmate meiosis and this is independent of its FEAR function.
authors.affiliation: School of Environment &Life Sciences, University of Salford, Manchester, UK.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Kerr
authors.affiliation: Bioinformatics Institute (A*STAR), 30 Biopolis Street, #07-01 Matrix, 138671, Singapore.
authors.forename: Jin Huei
authors.initials: JH
authors.lastname: Wong
authors.affiliation: Bioinformatics Institute (A*STAR), 30 Biopolis Street, #07-01 Matrix, 138671, Singapore.|Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore.
authors.forename: Prakash
authors.initials: P
authors.lastname: Arumugam
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D008540:Meiosis; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D018797:Cell Cycle Proteins; D004706:Endodeoxyribonucleases; D009687:Nuclear Proteins; D054648:Protein Phosphatase 2; D017027:Protein Tyrosine Phosphatases; D029701:Saccharomyces cerevisiae Proteins; C074860:CDC14 protein, S cerevisiae; C071246:CDC55 protein, S cerevisiae; C119300:Net1 protein, S cerevisiae; C416648:SPO12 protein, S cerevisiae; C518938:Spo11 protein, S cerevisiae; D000099257:Meiotic Recombination Protein SPO11