A cDNA encoding a putative thyroid-stimulating hormone receptor (cfTSH-R) was cloned from the testis of the African catfish (Clarias gariepinus). The cfTSH-R showed the highest amino acid sequence identity with the TSH-Rs of other fish species. In addition, an insertion of approximately 50 amino acids, specific for the TSH-R subfamily, was also present in the carboxy terminus of the amino-terminal extracellular domain of the cfTSH-R. Next to the testis and thyroid follicles, abundant cfTSH-R expression was detected in cerebellum, brain, ovary, seminal vesicles and pituitary, while weaker expression was found in muscle, stomach, intestine, head-kidney, liver, kidney and heart. HEK-T 293 cells, transiently expressing the cfTSH-R, significantly increased intracellular cAMP levels in response to human TSH. Catfish LH, human choriogonadotropin and human FSH were also able to induce this cfTSH-R-mediated response, although with considerably lower efficiency than human TSH. These results indicated that a functional cfTSH-R had been cloned from the testis of African catfish.

This article has been cited by other articles:

				N. R. Farid and M. W. Szkudlinski Minireview: Structural and Functional Evolution of the Thyrotropin Receptor Endocrinology, September 1, 2004; 145(9): 4048 - 4057. [Abstract] [Full Text] [PDF]