Question

There are 9 different types of membrane-bound adenylate cyclase (AdCy) enzyme. If you had a receptor that was linked to AdCy type II via a Gi type of G protein (i.e. a G protein for which the ? subunit is inhibitory), what would happen to signalling through this receptor if adaptation in the brain to an addictive drug caused the cell to express AdCy type VII rather than AdCy type II? Explain your answer.

Answer 1

we all know that most of the adenylate cyclase enzyme is respnsible for the formation of cAMP from ATP as a second messenger and then activates its signalling pathway.If there is a receptor specific for AdCy type II enzyme which is act through Gi type of G protein(inhibitory subunit) then that enzyme linked to its receptor and activates its pathway,But the cell express AdCy enzyme VII which had no receptor present in that cell so cell signalling will stop and no cAMP generation in that cell.