MCQ on GPCR Signaling (G protein Coupled Receptor)
1. GPCR is
a) an intracellular receptor
b) extracellular receptor with no intracellular
domain
c) 4 transmembrane domain receptors
d)
7 transmembrane domain
receptors
2. G protein of GPCR is located in the
a) Extracellular region
b) Cytosolic region
c) Transmembrane region
d) All of the above
3. G proteins are made up of
a) alpha, beta and gamma subunits
b) alpha and beta subunits
c) alpha subunits only
d) alpha, beta, gamma and delta subunits
4. G proteins of GPCR in its inactive state is bound
to
a) ATP
b) GDP
c) CTP
d) TTP
5. GPCR on ligand binding undergoes a confirmation
change and associated G protein gets activated by
a)
exchanging bound
GDP with GTP
b) exchanging bound GTP with GDP
c) exchanging bound ATP with ADP
d) exchanging bound ADP with ATP
6. In GPCR cAMP pathway, enzyme activated by G
protein that converts ATP to cAMP is
a) Peptidyl transferase
b)
adenyl cyclase
c) cyclic GMP-AMP synthase
d) guanyl cyclase
7. Which of the following statement is incorrect
regarding GPCR?
a) GPCR is also called as 7TM receptors
b) GPCR signals can activate second messengers like
cAMP, DAG and IP3
c) Around 30%-40% of the recommended drugs target
mainly GPCRs.
d)
GPCR is cytoplasmic
receptor
8. Which subunit of G protein is involved in the GDP-GTP
exchange upon activation by ligand binding?
a) Alpha subunit
b) Beta subunit
c) Gamma subunit
d) Both beta and gamma subunit
9. Elevated levels of second messenger; cAMP in
GPCR cAMP pathway further activates
a) Protein kinase A
b) RTK
c) Peptidyl transferase
d) phosphorylase
10.
CREB activated by GPCR signaling is
a) an enzyme
b) a transcription factor
c) is a conserved DNA sequence
d) is a kinase enzyme
This video may improve your understanding on GPCR Signaling
Answers
1. d) 7 transmembrane domain receptors
2. b) Cytosolic region
3. a) alpha, beta and gamma subunits
4. b) GDP
5. a) exchanging bound GDP with GTP
6. b) adenyl cyclase
7. d) GPCR is cytoplasmic receptor
8. a) Alpha subunit
9. a) Protein kinase A
10.b) transcription factor
