Cell Cycle Flashcards
cyclin and CDK of mid G1
cyclin D
CDK4/6
cyclin and CDK of late G1
cyclin E
CDK 2
cyclin and CDK of S
cyclin A
CDK 2
cyclin and CDK of M
cyclin A and cyclin B
CDK 1
What signal cascade leads to c-Fos transcription?
MAP kinase
What does c-Fos transcribe?
mid-G1:
cyclin D
CDK4/6
Which cyclin increases its level throughout G2 and peaks in M phase?
cyclin B
Which two CDK complexes are inhibited until DNA replication have completed?
cyclin A/CDK1
cyclin B/CDK1
What inhibits cyclin A/CDK 2?
p27KIP1
What effect does cyclin D, CDK4/6 have on Rb?
phosphorylates it and releases it from E2F
What does E2F do?
promotes the transcription of cyclin E/CDK2 and cyclin A/CDK2
When is ATM activated?
when there are double-stranded DNA breaks, caused by irradiation
When is ATR activated?
damages from UV light and certain drugs
How do ATM and ATR work?
- inhibit phosphatases that normally dephosphorylate CDK complexes which then activate S-phase and mitosis
- also promotes p53 stabilization allowing it to stimulate p21CIP1, an inhibitor of CDK1/2 (no S phase or M phase)
What disease is associated with mutation in the gene encoding ATM?
Ataxia Telangiectasia
What are PUMA, BID, BAX?
pro-apoptotic proteins
What is Bcl-2?
protein that is antiapoptotic and inhibits BAX
What is the channel-forming protein of the mitochondrial membrae?
BAX, leads to release of cytochrome c from the mitochonria
What stimulates BAX?
PUMA and BID
Which is the initiator caspase and which is excecutioner caspase?
caspase-9 (initiator caspase)»_space; caspase-3 (executioner caspase)
How does p53 trigger apoptosis?
by inducing pro-apoptotic proteins (PUMA, BID, BAX)
