L12 - The discovery of oncogenes

Question 1

charecteristic of cell signalling

Answer 1

switchable - On/Off

= signals must be tuned on but just as easily turned off

Question 2

what is v-Src

Answer 2

viral oncogene found in Rous sarcoma virus

= causes cancer in chickens
= mutant form –> c-Src (cellular Src)

Question 3

what is Src in terms of V-Src and C-Src

Answer 3

tyrossine kinasde

= phosphorylates tyrosine resides on proteins to activate sigannling pathways for growth and survival

Question 4

differebce between c-Src and v-Src

Answer 4

c-Src (normal):
contains reguklatory domain that keeps kinase activity OFF unless apropriat;ey activated

v-Src (oncogenic):
lacks part of regulatory domain due to mutations

= kinase is constituitively active
= mimics constantgrowth signal –> uncontrolled proliferation and evasion of cell death

Question 5

describe the key takeway of v-Src causing cancer

Answer 5

locks the signal ON bypassing normal regulatorty mechanisms that switch off growth signals

= uncontrolled cell division