Which of the following statements most accurately describes the role of heterotrimeric G proteins in signal transduction? Activation of G proteins by agonist-bound G protein-coupled receptors is initiated by the conversion of GDP to GTPat the a-subunit nucleotide binding site.
O Activation of G proteins by agonist-bound G protein-coupled receptors is initiated by the unbinding of GTP and
binding of GDP at the a-subunit nucleotide binding site.
Activation of G proteins by agonist-bound G protein-coupled receptors is initiated by the unbinding of GDP and
binding of GTP at the a-subunit nucleotide binding site.
Agonists binding to G proteins trigger their activation.