Identification and Analysis of Function of Heterotrimeric Guanine Nucleotide-Binding Proteins Expressed in Neural Tissue

Most neurotransmitters, hormones, and growth factors that cause alterations in the rate of synthesis of intracellular messengers interact with cell surface receptors that are members of a family of single polypeptide proteins. Secondary and tertiary structure predictions for such receptors indicate that they are glycoproteins in which highly hydrophobic blocks of amino acids produce seven trans -plasma membrane-spanning elements. In all known cases, such receptors are required to interact with members of a family of heterotrimeric guanine nucleotide-binding proteins (G proteins) before agonist-induced alterations in the enzymatic activity of intracellular messenger-generating systems can be detected.