Eukaryotic Cell Cycle L15/16 Flashcards
Name the four cyclin that regulate cell cycle transitions
Cyclin D (Cdk4/6)
Cyclin E (Cdk2)
Cyclin A (Cdk2)
Cyclin B (Cdk1)
Cdc25
What cyclin does Cdk4/6 bind to?
Cyclin D
…What does Cdc25 bind to?
…..
What cyclin does Cdk2 bind to?
Cyclin E
Cyclin A
What cyclin does Cdk1 bind to?
Cyclin B
Name the four cyclin dependent kinases that regulate cell cycle transitions
Cdk4/6
Cdk2
Cdk1
Cdc25
What is MPF? (not its name, what is it made up of)
Cyclin B bound to CDK1
Once cyclins have completed their job in the cell cycle, they are destroyed. What does this ensure?
That the events they control only happen at the correct moments in the cell cycle, (cell cycle stages don’t reoccur) allowing for unidirectionality
What do cell cycle cyclins accumulate in response to?
Growth factors and transcriptional activation
What are the two main roles cyclin-binding affects on a CDK?
Substrate specificity (what the kinase should phosphorylate)
Conformational change in activating T-loop, making T-loop a better substrate for cyclin dependent kinase activating kinase (CAK)
What does CDKI stand for?
Cyclin dependent kinase inhibitors (proteins)
What is p27?
A CDKI that binds to SPF during G1 to prevent promotion to S phase
Give three ways to inhibit CDKs?
Inhibitory phosphorylation
CDKIs (inhibitor proteins that bind to CDK)
Degradation of cyclin via ubiquitin mediated proteasome regulation
What cyclins are controlled by transcriptional regulation and then proteasome mediated degradation?
cyclin E, cyclin A and cyclin B
What is replication licensing?
The marking of DNA so that cells can copy it
