Lec 1 - Cell Cycle

Question 1

What are examples of transducers (also called in

Answer 1

RAS, RAF, g-proteins, non-receptor protein tyrosine kinases

Question 2

Helicase is activated via ________ by ______ activity

Answer 2

phosphorylation by g1/s activity

Question 3

what is the difference between G1 CDK activity and G1/S CDK activity

Answer 3

G1 CDK activity is activated by growth factors (also know at mitigens) and it causes pRB to be phosphorylated, releasing e2f. E@F triggers expression of g1/s cdk activity.
G1/S CDK activity - once this is expressed cell cycle beings (GF no longer required).
- g1/s cdk further phosphorylates RB, keeping e2f free
-activates helicase (which recruits polymerase)

Question 4

What type of cyclin is g1/s cyclin and when does it peak and what degrades it?

Answer 4

Cyclin E
Peaks at start of s phase
Proteolysis only (use of protease)

Question 5

Growth factors mechanism of action is ______ and bind to ____ receptors

Answer 5

receptor dimerization and bind to cognate receptors which are integral protien-tyrosine kinanses

Question 6

KRAS mutation is what type of mutation? what drug helps fix?

Answer 6

KRAS is a mutation that effects the signaling cascade. is it an oncogene mutation.

drug is Sotorasib and it works by targeting cystine in (G12C) and locking it into a signal off state - used in lung cance and pancreatic cancer

Question 7

CDK4/6 (G1/S CDK) inhibitors

Answer 7

Palbociclib binds to ATP binding pocket and blocks pRB activation and cell division in breast cancer patients

Question 8

p53 is a ____ and activates _____ and blocks ____

Answer 8

p53 is a TSG and activates p21 (a CDKi) and blocks BCL-2 which promotes cell death

Question 9

To make check points work you need these three things ___, ____, and ____. Give an example of each

Answer 9

sensors - detects problems like DSB or ssDNA. sensor protein ATM binds to DSB. ATR to ssDNA
**signal transducers **
effector

Question 10

three classifications of go or g1 cells

Answer 10

P- always G0 - nuerons, RBS
S - G0 but can be g1 (exmaple?)
Lible - always G1 (gut cells, skin cells)

Question 11

*How are check points enforces?

Answer 11

by temporarily inactivating cyclin/cdk complexes

Question 12

Every cancer cell has one or more ____

Answer 12

0ncogenes

Question 13

Oncogenic mutation is a ______ and can never be a ______

Answer 13

gain of function and can never be a null / loss of function

it is functionally dominant over wild type

ex: growth factor, RTK, signal cascade member, nuclear factor, KRAS, BCL-2

Question 14

TSG is a _____ mutation

Answer 14

loss of function mutatoin
functionally recessive
2nd allele lost by mutation in somatic cell

p53, pRB

Question 15

As a TF, p53 elevates ____, ____ and _____

Answer 15

CDKIs
expression of DNA repair genes apoptosis through downregulating BCL-2

Question 16

Aberrant ______ of signal transduction pathways is associated with cancer

Answer 16

stimulation