Single subunit structure of the human thyrotropin receptor.
We have produced rabbit antibody against a synthetic peptide corresponding to N-terminal region of the extracellular domain of human thyrotropin receptor (hTSH-R) (N peptide, aminoacid residues 29-57). Western blot analysis revealed that N-peptide antibody recognized recombinant hTSH-R stably expressing in CHO-K1 cells as a mol. wt. about 104 kDa regardless in the presence or absence of disulfide-reducing agent. The band was not detected in untransfected CHO-K1 cells and no band was also stained by the antibody absorbed with N-peptide. In a reducing condition, the antibody also bound the rat receptor from FRTL5 cells as the same molecular size (104 kDa). These results clearly indicate that TSH-R is composed of a single subunit and that two subunit model for the TSH-R may reflect artifactual proteolytic cleavage of the receptor during membrane preparation.
Endo
T
T
Third Department of Internal Medicine, University of Yamanashi Medical School, Japan.
Ikeda
M
M
Ohmori
M
M
Anzai
E
E
Haraguchi
K
K
Onaya
T
T
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D004247:DNA / Q000235:genetics; D006031:Glycosylation; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D011989:Receptors, Thyrotropin / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000737:chemistry; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D000906:Antibodies; D046911:Macromolecular Substances; D010446:Peptide Fragments; D011989:Receptors, Thyrotropin; D011994:Recombinant Proteins; D004247:DNA