Characterization of novel mutations at the Schizosaccharomyces pombe cdc2 regulatory phosphorylation site, tyrosine 15.

AUTOR(ES)

Gould, K L

RESUMO

The cdc2 protein kinase family is regulated negatively by phosphorylation in the glycine ATP-binding loop at a conserved tyrosine residue, Y15, alone or in combination with T14 phosphorylation. In Schizosaccharomyces pombe and other systems, substitution of these residues with structurally similar but nonphosphorylatable amino acids has generated proteins (Y15F or T14AY15F) that behave as constitutively tyrosine-dephosphorylated proteins or threonine and tyrosine-dephosphorylated proteins. Here we report the characteristics of three additional mutants at Y15--Y15E, Y15S, and Y15T--in S. pombe cdc2p. All three mutant proteins are active in in vitro kinase assays, but are unable to functionally complement cdc2 loss-of-function mutations in vivo. Additionally, all three mutants are dominant negatives. A more detailed analysis of the Y15T mutant indicates that it can initiate chromosome condensation and F-actin contractile ring formation, but is unable to drive the reorganization of microtubules into a mitotic spindle.

Documentos Relacionados

• Tyrosine Phosphorylation of Cdc2 Is Required for the Replication Checkpoint in Schizosaccharomyces pombe
• The Role of Cdc2 and Other Genes in Meiosis in Schizosaccharomyces Pombe
• Phosphorylation at Thr167 is required for Schizosaccharomyces pombe p34cdc2 function.
• Mutants at Ser277 of Xenopus cdc2 protein kinase induce oocyte maturation in the absence of the positive regulatory phosphorylation site Thr161.
• p13suc1 of Schizosaccharomyces pombe regulates two distinct forms of the mitotic cdc2 kinase.