Apoptosis, Cell Cycle, And Cancer

Question 1

G1 checkpoint

Answer 1

Occurs in response to DNA damage

Question 2

Restriction point

Answer 2

Occurs in response to not enough growth factors. This restriction will keep the cell in G0 until GFs are obtained

Question 3

G2 checkpoint

Answer 3

Ensures duplication integrity

Question 4

Metaphase checkpoint

Answer 4

Ensures chromosomes are attached to mitotic spindle

Question 5

What pathways will cells follow after the cell cycle?

Answer 5

Apoptosis, cell proliferation, or cell differentiation

Question 6

Myc-TF

Answer 6

Will drive cell proliferation by activating G1-CDK to phosphorylate Rb. Rb will then release E2F that will move the cell cycle from G1 to S

Question 7

E2F drives expression of what?

Answer 7

Cyclin E and cyclin A

Question 8

CDK2 and Rb

Answer 8

CDK2 will hyperphosphorylate Rb to activate E2F

Question 9

Cyclin

Answer 9

Cyclins must interact with CDK for CDK to be activated

Question 10

What is required for full activation of Clycin-CDK?

Answer 10

CDK activating kinase

Question 11

WEE1

Answer 11

WEE1 will phosphorylate the roof of CDK to prevent cyclin from binding in its active site

Question 12

CAK

Answer 12

In the inactive state, the T loop will be covering the CDK active site. When cyclin binds, the T loop will move out of the active site and CAK will be able to bind and full activate the CDK-cyclin complex

Question 13

G1 cyclins and CDKs

Answer 13

Cyclin D, CDK 4 and 6

Question 14

G1/S cyclin and CDK

Answer 14

Cyclin E and CDK2

Question 15

S phase cyclin and CDKs

Answer 15

Cyclin A and CDK2

Question 16

M phase cyclin and CDK

Answer 16

Cyclin A and B, CDK1

Question 17

Cyclin D purpose

Answer 17

Helps passage of cells from restriction point to G1

Question 18

Cyclin E purpose

Answer 18

Helps cells commit to DNA replication and enter S phase

Question 19

Cyclin A purpose

Answer 19

Necessary for initiation of DNA synthesis

Question 20

Cyclin A ad B purpose

Answer 20

Necessary for nuclear division during mitosis

Question 21

Cdc25

Answer 21

Will dephosphorylate the roof site to increase CDK activity

Question 22

P27

Answer 22

Bind CDK and cyclin to inhibit it

CKI

Question 23

APC/C

Answer 23

Regulates progression from metaphase to anaphase because Cyclin-S and Cyclin-M need to decrease activity.

Cdc20 will activate so that cyclins can be polyubiquitinated and degraded by proteosomes

Question 24

What normally degrades p53?

Answer 24

MDM2 - an E3 ubiquitin ligase

Question 25

P21

Answer 25

Activation of p53 leads to transcription of CKI p21 that will bind and inactive cyclin-CDK and cause cell arrest Can inhibit all cyclin/CDK complexes but is mainly associated with CDK2

Question 26

Pro-apoptotic

Answer 26

P53 BAX,BAK

Question 27

Pro survival

Answer 27

BCL-1, BCL-Xl

Question 28

BRCA1 is a result of a mutation in what receptor?

Answer 28

HER2 to NEU due to a Val —> Gln mutation

Question 29

Mutated p53

Answer 29

Located on chromosome 17 and monitors check points of cell cycle. Mutation is observed in more than 50% of all human tumors

Question 30

RB mutation

Answer 30

Regulates G1 phase of cell cycle. Located on chromosome 13 and seen in retinoblastoma

Question 31

APC mutation

Answer 31

On chr 5, regulates cell proliferation. It’s observed in familial adenomatous polyposis. Leads to colon cancer

Question 32

DCC mutation

Answer 32

Plays a role in cell proliferation, migration, and apoptosis. Located on Chr 18 and mutations are seen in colon cancer

Question 33

BRCA1/BRCA2 mutation

Answer 33

Chromosome 17, plays a role in DNA repair and apoptosis Observed in breast cancer

Question 34

NF-1 mutation

Answer 34

Chr 17. Encodes GAP which will turn off activated RAS protein. Mutations in NF-1 lead to neurofibromatosis