Question

Place the events related to the initial steps of GPCR signaling below in the correct order.

1) G protein binds to activate receptor forming a receptor G protein complex
2) release of GDP by the G protein
3) change in conformation of the cytoplasmic loops of the receptor
4) binding of GTP by the G protein
5) Increase in the affinity of the receptor for a G protein on the cytoplasmic surface of the membrane
6) binding of a hormone or neurotransmitter to a G protein coupled receptor
7) conformational shift in the alpha subunit of the G protein

Answer 1

The initial steps of GPCR signaling occur in the following order: hormone/ neurotransmitter binding, change in receptor conformation, binding of G protein to receptor, release of GDP by G protein, binding of GTP by G protein, conformational shift in alpha subunit, increase in receptor affinity for G protein.

Step-by-step explanation:

1. Binding of a hormone or neurotransmitter to a G protein-coupled receptor.
2. Change in conformation of the cytoplasmic loops of the receptor.
3. G protein binds to activate receptor forming a receptor G protein complex.
4. Release of GDP by the G protein.
5. Binding of GTP by the G protein.
6. Conformational shift in the alpha subunit of the G protein.
7. Increase in the affinity of the receptor for a G protein on the cytoplasmic surface of the membrane.