Functional analysis of the cytoplasmic domains of the human thyrotropin receptor by site-directed mutagenesis.

摘要: The thyrotropin (TSH) receptor belongs to a family of guanine nucleotide protein-coupled receptors with seven transmembrane-spanning regions joined regulatory together by extracellular and intracellular loops. cytoplasmic domain comprises three loops tail that are likely be important in coupling the proteins. To address question which portions TSH this process, we have altered groups amino acids region site-directed mutagenesis. Because low affinity binding mutated terminus second loop tail, definitive conclusions cannot made regarding roles these signal transduction. However, our data indicate first (residues 441-450), carboxyl-terminal 528-537), (but not amino-terminal) third 617-625) ability mediate an increase cAMP production. Furthermore, two-thirds end 709-764; corresponding conserved between lutropin/chorionic gonadotropin receptors) can removed without functional impairment receptor.