In an examination of the signaling events in a myocyte cell line in culture, you find that addition of an α₁-adrenergic agonist does not lead to the expected release of stored intracellular calcium into the cytoplasm. You ascertain that the receptors for the agonist are present and that the agonist does indeed bind to the receptor. Given these results, which of the following proteins is most likely to be defective in these cells? A) a G_s-type G-protein B) a G_q-type G-protein C) phosphatidic acid phosphatase D) phosphatidylinositol-3-kinase (PI3K) E) protein kinase A (PKA)

Question

Quizplus · Accepted Answer

The α1-adrenergic receptor typically signals through a Gq-type G-protein, which activates phospholipase C, leading to the release of intracellular calcium. If calcium release is not occurring, the Gq protein may be defective.

In an Examination of the Signaling Events in a Myocyte