6: cell cycle Flashcards
When is the 1st check of the cell cycle?
late G1 phase, is cell DNA good enough to go to the Sphase → not = cell arrest
When isthe 2e check of the cell cycle?
late G2 → is all DNA Replicated for mitosis
When is the 3de check of the cell cycle?
M check → are all Chromosomes attacked to the spindles
how are the checkpoints controlled?
by Cyclin cDK
on what levels is cycli n CDK regulated?
- phosphorylation
- Ubiquitination
- inhibitory proteins
~ cyclins production (RTK growth)
key components of the cell cycle? (Cyclin)
- only active when Cdk is bound to a cyclin
- activity rice and fall during cell cycle because of different cyclin levels
- different classes of cyclin
- cyclins activate CDK and determine substrate
- can be suppressed by Var ious Mechanisms
What happens if there is to much Myc?
P53 gets activated by removal from active Mdm2 via arf
2 outcomes :
cell cycle arrest
Apoptosis last resort
what happens When p53 is not needed?
degration
what is needed for a functional CD k ?
phosphorylation
Inhibitor and activator for regulation
What is CAK?
CDK activating kinase
what is CIK?
CDK inhibitory kinase
What is CKI
inhibits through binding
What does p27 do?
in activate cyclin - CDK complex
what is the result of mutations in protein Rb?
loss of control of E2f activity causing Retinoblastoma
Where are heridetairy tumors most associated with?
Mutations of the RB1 tumor suppressor gene
