G proteins are a family of intracellular proteins capable of mediating signal transduction pathways by binding to receptor proteins which have bound their respective extracellular ligands (e.g. neurotransmitters and hormones).
G proteins are a family of intracellular proteins capable of mediating signal transduction pathways by binding to receptor proteins ligands (e.g. neurotransmitters). G proteins are a family of intracellular proteins capable of mediating signal transduction pathways by binding to receptor proteins ligands (hormones). These receptor proteins have bound their respective extracellular.