cell cycle fundamental processes Flashcards
G1
Cells only grow
G0
checkpoint
S phase
DNA synthesis + growth (more organelles made)
G2
checks made, before committing to mitosis
-‘plasia’ meaning
growth/proliferation
necrosis is …
unprogrammed cell death
How is metaphase an important checkpoint
- sensors for tension across centromere
- if tension is not equal
- signals to nucleus
- prevents uneven pulling
M cell + any other cell ….
dominant biochemical signal from mitotic cell signals other cell to divide
G1 cell + S phase cell
S phase signal is dominant
S phase cell + G2 cell
= G2 delay
cell doesn’t progress unless all all aDNA is synthesised
alternation (define + proteins involved)
- Cell cycle events occur in the right order
- cyclins and cdks
completion
one process must finish before the next one starts
cyclin binding cdk =
phosphorylation of cdk (by CAK)
cdks inhibited by phophphorylation (where and by what kinases)
at T14 and Y15
by wee1 and mik1
a promoter of mitosis
Cdc25 (phosphatase) - takes phosphate off of Cdks (and activates them?)
cdkis
cyclin dependant kinase inhibitors
CDKN2 (INK4)
bind and inhibit cdk4/6
CDKN1
inhibit E- and A- dependant cyclins
4 stages of cell cycle and the cyclin/cdk involved
- G1 - cyclin D, cdk4/6
- S - cyclin E, cdk2
- G2 - cyclin A, cdk2
- M - cyclin B, cdk1
cyclin c + cdk1 complex
phosphorylates APC
degradation of cyclin B (when tagged by Ub)
trigger for anaphase
anaphase checkpoint prevents …
aberrant mitosis (not proper chromosome separation)
growth factor signalling is required for …
passage through G1 restriction (R) checkpoint
G1 checkpoint -
draw it out
Rb is a …
transcription repressor
p27kip1 inhibits …
the cyclin E + cdk2 complex
