[TRH receptor].

Thyrotropin-releasing hormone (TRH) receptor (TRHR) cDNAs have been cloned from several species since 1990. Sequence analysis of these cDNAs showed that TRHR belongs to the family of G-protein coupled receptors containing seven transmembrane domains. The human gene spans more than 30 kb and contains three exons and two introns, which located on chromosome 8q23. Several new evidences have been reported including primary structure of TRHRs, distribution of TRHR mRNA, three dimensional structure of the TRH binding pocket, structure of the TRHR gene promoter, G-proteins and TRHR etc. Furthermore, a patient with central hypothyroidism caused by compound mutations of the TRHR gene and a novel transcript of TRHR gene in the pituitary have been recently reported.