Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
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Drug
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Target Concepts:
Gene/Protein
Disease
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Query: EC:3.1.3.16 (
calcineurin
)
17,112
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The
CAK1
gene encodes the major CDK-activating kinase (CAK) in budding yeast and is required for activation of Cdc28p for cell cycle progression from G2 to M phase. Here we describe the isolation of a mutant allele of
CAK1
in a synthetic lethal screen with the Sit4
protein phosphatase
. Analysis of several different cak1 mutants shows that although the G2 to M transition appears most sensitive to loss of Cak1p function, Cak1p is also required for activation of Cdc28p for progression from G1 into S phase. Further characterization of these mutants suggests that, unlike the CAK identified from higher eukaryotes, Cak1p of budding yeast may not play a role in general transcription. Finally, although Cak1 protein levels and in vitro protein kinase activity do not fluctuate during the cell cycle, at least a fraction of Cak1p associates with higher molecular weight proteins, which may be important for its in vivo function.
...
PMID:The Cak1p protein kinase is required at G1/S and G2/M in the budding yeast cell cycle. 928 68
Activating phosphorylation of cyclin-dependent protein kinases (CDKs) is necessary for their kinase activity and cell cycle progression. This phosphorylation is carried out by the Cdk-activating kinase (CAK); in contrast, little is known about the corresponding
protein phosphatase
. We show that type 2C protein phosphatases (PP2Cs) are responsible for this dephosphorylation of Cdc28p, the major budding yeast CDK. Two yeast PP2Cs, Ptc2p and Ptc3p, display Cdc28p phosphatase activity in vitro and in vivo, and account for approximately 90% of Cdc28p phosphatase activity in yeast extracts. Overexpression of PTC2 or PTC3 results in synthetic lethality in strains temperature-sensitive for yeast
CAK1
, and disruptions of PTC2 and PTC3 suppress the growth defect of a cak1 mutant. Furthermore, PP2C-like enzymes are the predominant phosphatases toward human Cdk2 in HeLa cell extracts, indicating that the substrate specificity of PP2Cs toward CDKs is evolutionarily conserved.
...
PMID:Dephosphorylation of cyclin-dependent kinases by type 2C protein phosphatases. 1058 2
