Question

What is the main consequence of cAMP pathway activation by alpha2- and beta-adrenoreceptors?

a) Inhibition of protein kinase
b) Activation of protein kinase
c) Opening of potassium channels
d) Calcium influx into the cell

Answer 1

The activation of the cAMP pathway by alpha2- and beta-adrenoreceptors triggers the activation of protein kinases, specifically A-kinase, which leads to phosphorylation and activation of target proteins.

Step-by-step explanation:

The main consequence of cAMP pathway activation by alpha2- and beta-adrenoreceptors is the activation of protein kinase. This involves the cAMP-dependent kinase (also known as A-kinase or PKA) which is a group of protein kinases. These kinases phosphorylate serine and threonine residues on their target proteins, which activates them and initiates various cellular responses. The activated G-protein linked to these receptors turns on adenylyl cyclase, which then converts ATP to cAMP. In turn, cAMP activates A-kinase, leading to the phosphorylation of substrate molecules and the mediation of changes in cellular processes.