Question

Which of the following is a major consequence of activation of phospholipase C-β (PLCβ) by the Gq trimeric GTPase?

A. Elevation of intracellular cAMP levels, leading to the activation of protein kinase A
B. Elevation of PIP3 levels in the plasma membrane, leading to the activation of protein kinase B
C. Elevation of intracellular Ca2+ levels, leading to the activation of protein kinase C
D. Elevation of IP3 in the plasma membrane, leading to the activation of protein kinase D
E. Elevation of intracellular cGMP levels, leading to the activation of protein kinase G

Answer 1

Activation of phospholipase C-β (PLCβ) by Gq trimeric GTPase leads to increased intracellular Ca2+ levels, which activates protein kinase C.

Step-by-step explanation:

The major consequence of activation of phospholipase C-β (PLCβ) by the Gq trimeric GTPase is the elevation of intracellular Ca2+ levels, leading to the activation of protein kinase C (PKC). When PLCβ is activated, it catalyzes the formation of cytosolic inositol triphosphate (IP3) and membrane-bound diacylglycerol (DAG), both serving as second messengers. IP3 then binds to receptors on the smooth endoplasmic reticulum, causing the release of Ca2+ ions into the cytoplasm. The surge in Ca2+ and the presence of DAG together activate PKC, initiating a phosphorylation cascade leading to various cell-specific responses.