Question

There are various types of G-protein coupled receptors. Two of the most common G-protein coupled Rc's are Gs and Gq receptors. Which enzymes and 2nd messengers do these receptor subtypes use?

Answer 1

The Gs and Gq subtypes of G-protein coupled receptors activate different enzymes: adenylate cyclase and phospholipase C, respectively. These enzymes produce second messengers cAMP for Gs and IP3 and DAG for Gq, which regulate various cellular functions through protein kinase A and protein kinase C.

Step-by-step explanation:

The G-protein coupled receptors (GPCRs) such as Gs and Gq utilize various enzymes and second messengers to transduce signals inside the cell. When activated by a ligand, the Gs subtype of GPCRs stimulates the enzyme adenylate cyclase, which consequently increases the levels of cyclic AMP (cAMP) in the cell. This cAMP serves as a second messenger, activating protein kinase A (PKA), which can then go on to phosphorylate target proteins and regulate diverse cellular processes. On the other hand, activation of Gq coupled receptors leads to the activation of the enzyme phospholipase C (PLC). PLC cleaves a membrane lipid to generate two second messengers, inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG). IP3 triggers the release of calcium ions (Ca2+) from intracellular stores, while DAG activates protein kinase C (PKC), both of which are involved in various cellular responses.