What is the role of Cdc25?
CDC25C is a cyclin of the specific phosphatase family that activates the cyclin B1/CDK1 complex in cells for entering mitosis and regulates G2/M progression and plays an important role in checkpoint protein regulation in case of DNA damage, which can ensure accurate DNA information transmission to the daughter cells.
Does Cdc25 phosphorylate?
Phosphorylation-dependent activation of CDC25C. Several kinases phosphorylate human CDC25C during mitosis. In human, CDC25C also found to play a similar role in meiotic cells. During meiosis, CDC25C is phosphorylated and localized just like during mitotic divisions.
How is Cdk1 regulated?
Given its essential role in cell cycle progression, Cdk1 is highly regulated. Most obviously, Cdk1 is regulated by its binding with its cyclin partners. Cyclin binding alters access to the active site of Cdk1, allowing for Cdk1 activity; furthermore, cyclins impart specificity to Cdk1 activity.
What does Wee1 kinase do?
Wee1 Kinase. Wee1 is a nuclear protein involved in the regulation of the G2/M checkpoint by negatively regulating entry into mitosis by catalyzing an inhibitory tyrosine phosphorylation of the Cdc2/cyclin B kinase complex.
What does cdc25 do to cdc2?
Phosphorylation of cdc25-C in mitotic HeLa extracts or by cdc2-cyclin B increases its catalytic activity. cdc25-C is not a substrate of the cyclin A-associated kinases. cdc25-C is able to activate cdc2-cyclin B1 in Xenopus egg extracts and to induce Xenopus oocyte maturation, but only after stable thiophosphorylation.
What are CDC6 and Cdt1?
CDC6 is an ATP binding protein and a member of the pre-replicative complex (pre-RC) together with the origin recognition complex (ORC), Cdt1 and the MCM complex (containing MCM2-7p). CDC6 assembles after ORC in an ATP dependent manner and is required for loading MCM proteins onto the DNA.
Is CAK a kinase?
In budding yeast, CAK is a monomeric protein kinase and is referred to as Cak1. Cak1 is distantly homologous to Cdks. Cak1 localizes to the cytoplasm and is responsible for Cdk activation.
What activates Cdc25 phosphatase?
The M-phase inducer, Cdc25C, is a dual-specificity phosphatase that directly phosphorylates and activates the cyclin B/Cdc2 kinase complex, leading to initiation of mitosis. Cdc25 itself is activated at the G2/M transition by phosphorylation on serine and threonine residues.
What happens if CDK1 is inhibited?
Our finding that inhibition of CDK1 can damage normal cells in a cell cycle dependent manner indicates that targeting CDK1 in cancer patients may lead to toxicity in normal proliferating cells.
What does CDK1 do in the cell cycle?
CDK1 promotes multiple biological processes that are critical for cell survival, including G2/M transition, checkpoint activation, DNA repair, and DNA replication as we propose. Its activities in these processes compromise the efficacy of chemotherapeutic drugs and may contribute to chemoresistance (a).
What is the wee phenotype?
Deficiency in wee1 causes premature mitotic entry, resulting in small size in yeast (hence the “wee” phenotype).
How does Wee1 influence MPF?
MPF activity can be regulated by reversible association with the Cdk inhibitor Rum1, as well as by phosphorylation and dephosphorylation by the inhibitory kinase Wee1 and the activating phosphatase Cdc25, respectively. MPF inhibits Rum1 and Wee1, while it activates Cdc25.