Signal Transduction Flashcards
1
Q
what does G protein type Gαq (or Gq) stimulate?
A
phospholipase C
2
Q
what does G protein type Gs do?
A
- stimulates adenylate cyclase
- increases cAMP
3
Q
what does G protein type Gi do?
A
- inhibits adenylate cyclase
- decreases cAMP
4
Q
how is cAMP synthesised?
A
within cells from ATP by enzyme adenylate cyclase
5
Q
how is cAMP degraded?
A
by enzyme cAMP phosphodiesterase
6
Q
what is cholera toxin?
A
- Oligomeric complex which after cleavage becomes active and enters intestinal epithelial cells to stimulate Gαs
- The overstimulation of cAMP production results in a release of water and ions including Na+, K+, Cl- and HCO3- into the lumen of the small intestine
7
Q
what toxin acts in reverse to cholera toxin?
A
Pertussis toxin: acts in the reverse manner inhibiting Gαi to increase cAMP production in lung epithelia
8
Q
what protein activates the MAPK (mitogen-activated protein kinase) pathway?
A
Ras
9
Q
what type of cancer is associated with EGFR overexpression?
A
- colorectal cancer
- pancreatic cancer
- lung cancer
- non-small cell lung cancer
10
Q
what is EGFR?
A
- epidermal growth factor receptor
- RTK activated by TGFα (transforming growth factor alpha)
