Which one of the following statements best describes the mechanism of action of insulin on target cells?
Ans. (C) Insulin binds to a transmembrane receptor at the outer surface of the plasma membrane, which activates the tyrosine kinase that is the cytosolic domain of the receptor.(KDT 8th/e p58)Enzymatic Receptors have two sites, the drug binds on the extracellular site and the intracellular site has enzymatic activity (mostly tyrosine kinase). This enzyme can be activated via JAK-STAT pathway. Insulin, growth hormone, prolactin and cytokines act via enzymatic receptors.
Insulin binds to cytoplasmic receptor molecule and is transferred as a hormone receptor complex to the nucleus where it acts to modulate gene expression.
Insulin binds to a receptor molecule on the outer surface of the plasma membrane and the hormone receptor complex activates adenylate cyclase through the Gs protein.
Insulin binds to a transmembrane receptor at the outer surface of the plasma membrane, which activates the tyrosine kinase that is the cytosolic domain of the receptor.
Insulin enters the cell and causes the release of calcium ions from intracellular stores.
General Pharmacology