mitosis and cell cycle Flashcards
(30 cards)
CDK subunit is normally ____ and binding of ____ makes it ____
inactive, binding of cyclin makes it active
what changes during the cell cycle to regulate CDK activity
cyclin
what, besides cyclin, helps regulate CDK activity through cell cycle
CDK inhibitors
what is Rb protein
inhibitor of cell cycle during cell division
what inhibits Rb
CDK phsphorylation
what status of Rb and CDK must exist for replication
Rb inactive by CDK phosphorylation and CDK negative
CDI means
CDK inhibitors
what are the two classes of CDI
Cip/Kip and INK4
p21 is what class of CDI
cip
p27 is what class of CDI
Kip
what do p21 and p27 do
inhibit all CDks
p15 and p16 are what class of CDI and what do they do
INK4 specifically inhibit CDK4/6-cyclin D complexes
what is the p16 CDI a tumor suppressor for
melanoma and other cancers
what do mitogens and growth factors cause
production of cyclinD1-3
what does cyclinD1-3 do
acivates CDK4/6
what does activated CDK4/6 do
phosphorylates and inhibits Rb–> entry into cell cycle and S phase
where do mitogens act
cell surface
what do mitogens cause
an increase in cyclin D1 transcription–> increase in cyclin D1-3 proteins and more CDK4/6 cyclin- D1-3 active protein kinase compiles
where is replication always regulated
origin or initiation level
what is PreRC
a multi protein complex loaded onto origins in G1 phase
a major protein in the PreRC complex is _____ and that does what and is activated by what
MCM DNA helicase- opens up DNA for replication after being actuated by S-CDK complexes
what does PreRC cycle prevent and assure
prevents rereplication and assures that S phases are always followed by an M phase because the PreRC can only be loaded during G1 and activated during S (different phases prevents re-replication)
PreRC activation in s phase requires what two protein kinases
CDK with cyclins E and E (SCDK) and DDK
during the DNA damage checkpoint, CDK cyclin complexes are inhibited by what
p53 and Chk2
