Cell Cycle Control

Front 1

interphase

Back 1

all periods of the cell cycle except for mitosis or meiosis

Front 2

g1 phase

Back 2

Gap 1 = period following mitosis/meiosis w/ no dna replication

Front 3

g0 phase

Back 3

secescent phase; arrested g1 phase ; cells that cease to divide go into this phase

Front 4

S phase

Back 4

synthetic phase; period of dna replication

Front 5

g2 phase

Back 5

period between dna replication completion and the onset of mitosis

Front 6

cyclins

Back 6

major cell cycle regulatory proteins, mRNA /protein levels oscillate throughout cell cycle ; cyclin degradation allows for cell cycle phases to progress

Front 7

g1 cyclins ; C,D,E

Back 7

C,D,E, expressed during G1 phase, controls progression of g1-s phase

Front 8

g2 cyclins; A,B

Back 8

A,B expressed during g2/m stages ; controls g2--> m progression

Front 9

Cyclin dependent kinases

Back 9

kinases that are activated by cyclin binding ; cdk levels dont change during cell cycle but ENZYMATIC activities DO CHANGE ; kinases PHOSPHORYLATE threonine/tyrosine residues

Front 10

G1 CDK'S

Back 10

Cdk2,4 ; activated by G1 cyclins

Front 11

cdc2 (g2 CDK)

Back 11

bound and activated by g2 cyclins

Front 12

MPF - mitotic promoting factor

Back 12

G2 CYCLIN/ cdc2 complexes induce mitosis via phosphorylation of NUCLEAR LAMINS and H1 HISTONES

Front 13

Checkpoints

Back 13

signals that decide to progress to different phases of the cell cycle
- function --> block cell cycle progression until dna damage c

Front 14

tumor suppressors

Back 14

p53/rb
- checkpoints are mediated by tumor suppressors --> inhibit cell cycle progression

Front 15

Retinoblastoma (RB)

Back 15

tmr suppressor
- blocks g1-->s progression until G1 CYCLIN/Cdk complexes reach critical level
- mid G1--> hyprphsphryltn causes release of E2F --> causes progrssion to s-phase
- e2f activtes e2f transcription as well as g1/cyclin cdk activation --> causes + feedback and faster initiation of s-phase

Front 16

p53

Back 16

-rspnds to dna damage
-blocks cc progression or induces apoptosis
- p53 actviates p21
- p21 inhibits ALL G1/G2 cyclin/cdk complexes --> thus blocking cc progression @ g1-S and g2-m transitions

Front 17

if dna damage is too bad, what happens?

Back 17

p53 initiations apoptosis via BAX