T2- TSG's

Question 1

RB binds to and inactivates

Answer 1

E2F

Question 2

E2F can dimerize with DP and activates __

Answer 2

transcription

Question 3

RB is a major on/off switch for the

Answer 3

G1–> S checkpoint

Question 4

what happens if a person only have 1 functional gene for RB

Answer 4

can go through checkpoint much faster and more likely to develop retinoblastoma

Question 5

CDK inhibitors mainly work by

Answer 5

binding the CDK so that it can’t be phosphorylated.

Question 6

what is p53

Answer 6

a tumor supressor gene that is a DNA binding protein that regulates the transcription of several other genes.

Question 7

p53 increases expression of__

Answer 7

p21 (CDK inhibitor) and GADD45 (growth arrest and DNA damage–promotes repair)

Question 8

if DNA repair is not successful

Answer 8

p53 activates production of apoptosis–inducing BAX

Question 9

if DNA repair is successful

Answer 9

p53 activates production of MDM2, which promotes degradation of p53 since its job is done.

Question 10

syndrome in which the person is only born with 1 functional p53 allele.

Answer 10

Li-Fraumeni syndrome (LFS)

Question 11

what activates p53

Answer 11

it has to be phosphorylates

Question 12

name and describe the 3 kinases that activate p53

Answer 12

1. ATM (ataxia telangiectasia mutated)–> respond to sensors when sDNA breaks and stops cell cycle to allow for DNA repair
2. ATR–> respond to ssDNA damage
3. Chk1 and Chk2–> ser/thr kinases that are activated by ATM and ATR kinases to respond to DNA damage.

Question 13

if p53 is NOT phosphorylated it is bound to mdm2:

Answer 13

an E3 ubiquitin-protein ligase and important negative regulator of p53.
-USP7 removes ubiquitin groups form p53, thus stabilizing and promoting p53 activity.

Question 14

WNT ligands bind to the ___ receptor. WNT signals are _____ signals

Answer 14

WNT. pro growth signals

Question 15

Pitt Hopkins syndrome mutation

Answer 15

no TCF. no transcription inhibitors.

Question 16

3 isoforms of TGF-beta

Answer 16

B1, B2, B3

Question 17

TGF-beta mediates

Answer 17

an anti growth signal. activates a cascade of 2nd messengers –> the SMADS

Question 18

SMADs

Answer 18

1. r-SMAD–> receptor stimulated
2. I-SMAD–> inhibitory
3. Co-SMAD–> SMAD4

Question 19

For SMAD to bind to DNA and promote transcription it has to

Answer 19

dimerize with SMAD4

Question 20

purpose of SMURF

Answer 20

ubiquinates SMAD which promotes degradation.

Question 21

if you overexposes smurfs, you kill

Answer 21

all the SMADs and their won’t be any anti-growth signals= cancer.

Question 22

NF-1

Answer 22

gene that is mutated codes for GAP

Question 23

if you have a mutated GAP

Answer 23

then Ras will stay active much longer.

Question 24

NF-2

Answer 24

MERLIN gene–> coding coordinates membrane receptor signaling and cell:cell contact

Question 25

NF-2 deficiency results in developing of

Answer 25

benign bilateral schwannomas of the vestibular nerve

Question 26

VHL is a protein that is

Answer 26

missing a ubiquitin ligase and promotes degradation of HIF1alpha

Question 27

loss of VHL–>

Answer 27

increased HIF1alpha activity–> increased angiogenic growth factor synthesis.

Question 28

PTEN pathway

Answer 28

2nd messenger system:
-binding of ligand to membrane receptors activates PI3K.
Activated PI3K phosphorylates PIP2 to produce PIP3.
- PIP3 recruits PDK1 to the plasma membrane: PDK1 phosphorylates and activates AKT
-PTEN dephosphorylates PIP3.

Question 29

cowden syndrome is a mutation of the

Answer 29

PTEN. characterized by multiple tumor like growths

Question 30

E-cadherin acts as an

Answer 30

invasion suppressor.

Question 31

KLF6 is

Answer 31

an important TSG, mutated in 75% of prostate cancer. increases transcription of p21 and TGF-beta receptors.

Question 32

G2/M checkpoint ensures

Answer 32

that DNA damage that occurs during/after replication is repaired before cell enters mitosis.

Question 33

mutated CDC25

Answer 33

unable to be phosphorylated by CHK1–> no G2 arrest.