The amino-terminal half of the cytoplasmic tail of the thyrotropin receptor is essential for full activities of receptor function.
We investigated the role of the cytoplasmic tail of the thyrotropin receptor (TSHR) in signal transduction using mutants with truncation at the cytoplasmic tail. Mutant without residues 700-764 completely lost inositol phosphate response to agonists and showed decreased basal cAMP level. Mutant without residues 710-764 showed full cAMP responses but blunted inositol phosphate responses. However, mutant without residues 722-764 retained all signal transduction activities. These findings suggest that the amino-terminal half of the cytoplasmic tail (up to residue 721) is essential for full expression of functional activities.
Kosugi
S
S
Department of Laboratory Medicine, Kyoto University School of Medicine, Japan.
Mori
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D015153:Blotting, Western; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D015342:DNA Probes; D007295:Inositol Phosphates / Q000378:metabolism; D008961:Models, Structural; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D051381:Rats; D011989:Receptors, Thyrotropin / Q000096:biosynthesis / Q000737:chemistry* / Q000502:physiology*; D015398:Signal Transduction; D013972:Thyrotropin / Q000378:metabolism; D014162:Transfection
D015342:DNA Probes; D007295:Inositol Phosphates; D011989:Receptors, Thyrotropin; D013972:Thyrotropin; D000242:Cyclic AMP