Question

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

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

Answer 1

Activation of a Gq alpha subunit initiates the phospholipase C/DAG/IP3 signaling cascade, leading to various cellular responses.

Step-by-step explanation:

The outcome of activation of a Gq alpha subunit is c. Initiation of the phospholipase C/DAG/IP3 signaling cascade. When the Gq alpha subunit is activated, it interacts with and activates the enzyme phospholipase C, which then catalyzes the formation of diacylglycerol (DAG) and inositol triphosphate (IP3).

IP3 stimulates the release of calcium ions from the smooth endoplasmic reticulum into the cytosol, while DAG, along with the released calcium ions, activates Protein Kinase C (PKC) which in turn can lead to various cellular responses including gene expression, metabolism, and cell motility.