Chapter 17: Cell cycle Flashcards
MPF
- Maturation promoting factor
- made up of Cyclin B and CDK1
- induces entry into M phase
When are cyclins degraded and where do they accumulate?
Cyclins accumulate in interphase and are degraded at the end of mitosis
Wee1 function?
phosphorylates CDK1, inactivating MPF
Cdc25 function?
phosphatase the dephosphorylates CDK1, activating MPF
How is Cyclin B degraded?
After mitosis via ubiquitynilation by APC/C
4 mechanisms that regulate CDK’s?
- cyclin association
- activating phosphorylation
- inhibiting phosphorylation
- CDK inhibitor association
Cyclin D is synthesized in reponse to?
growth factors
Unregulated cyclin D results in?
cancer
Properties of the Rb protein?
- First identified in patients with retinoblastoma
- absence results in cancer
- tumor suppressor gene
- activity regulated by phosphorylation
Effect of phosphorylation on Rb
- phsophorylated by CDK4,6/Cyc D
- disassociation from E2F
- activation of transcription
CDK2/Cyclin E function in what phase?
entry into S phase
p27 function?
inhibits CDK2/cyc E activity in G0 and ealry G1
MCM helicase function?
- regulate DNA replication
- require phosphorylation to be active
- phosphorylated by DDK
cell cycle arrest mediated by?
ATM and ATR
p53 is phosphorylated by?
ATM and Chk2
condensation are activated by phosphorylation by?
CDK1/ Aurora kinase B
lamins are phosphorylated by?
Cdk1/Cyclin B
golgi matrix proteins are phosphorylated by?
Cdk1/Polo-like kinases
Mitotic checkpoint complex composed of?
- BubRI
- Bub3
- Mad2
- Cdc20
Cytokinesis is mediated by?
contractile ring of myosin and actin
5 stages of recombination
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis
LZPDD
