NURSING ANM AND GNM

Detailed explanation-1: -Any change in cAMP level directly impacts on PKA function. Hence, phosphodiesterases that hydrolyze cAMP represent another mechanism controlling PKA activity. PKA also requires regulatory phosphorylation of its activation segment.

Detailed explanation-2: -This acts as a negative feedback mechanism to inhibit high levels of rMLC phosphorylation. PKA phosphorylates MLCK at two sites, A and B. Phosphorylation at site A, but not at site B, decreases the affinity of MLCK for the Ca2+–calmodulin complex, and this is responsible for desensitization.

Detailed explanation-3: -Epinephrine and glucagon affect the activity of protein kinase A by changing the levels of cAMP in a cell via the G-protein mechanism, using adenylate cyclase.