Flashcards in 30_DNA Damage & Cell Cycle Checkpoints Deck (17)
What are the cell's three reactions to DNA damage?
2) activate checkpoint, arrest cell cycle
The cell cycle halts if two critical events are incomplete; what are they?
DNA replication in S phase
Chromosome alignment during M phase
What is the inheritance pattern of ataxia-telangiectasia?
What type of radiation are patients with AT sensitive to?
ionizing radiation (causing dsDNA breaks)
Which gene is mutated in AT patients?
What are ATM and ATR activated by?
ATM: dsDNA breaks
ATR: ssDNA breaks
What type of DNA damage does UV radiation induce?
Which type of radiation induces double-stranded DNA breaks?
Which checkpoint kinases do ATM and ATR activate?
Which protein is dubbed the "guardian of the genome"? At which stage does it arrest the cell cycle?
G1 => S
Cdc25 is a (kinase/phosphatase).
What effect does phosphorylation have on cdc25?
results in its shuttling to the cytoplasm. CDK complex remains inactive, and cell cycle is arrested at G2-M.
Is p53 stable in its phosphorylated or dephosphorylated form?
As a result of phosphorylation of p53, what genes are transcribed more?
p21 - CDI & Bax
What does p21 CDI inhibit?
G1 and S CDKs
What is the consequence of Bax upregulation?