Question

What is the outcome of activation of a Gs alpha subunit?

a. Inhibition of the adenylyl cylcase/cAMP signaling cascade
b. Inhibition of the phospholipase C/DAG/IP3 signaling cascade
c. Initiation of the phospholipase C/DAG/IP3 signaling cascade
d. Initiation of the adenylyl cylcase/cAMP signaling cascade

Answer 1

Activation of a Gs alpha subunit results in the initiation of the adenylyl cyclase/cAMP signaling pathway, which leads to a phosphorylation cascade affecting cellular processes.

Step-by-step explanation:

The outcome of activation of a Gs alpha subunit is the initiation of the adenylyl cyclase/cAMP signaling cascade. When the activated alpha subunit associates with adenylyl cyclase, it catalyzes the conversion of ATP to cAMP. This cAMP then serves as a second messenger in the cell, activating protein kinases like protein kinase A (PKA), which begins a phosphorylation cascade that ultimately alters various cellular processes including gene expression.