The calcitonin receptor on T 47D breast cancer cells. Evidence for glycosylation.
The glycosyl nature of the receptor for the peptide hormone calcitonin has been investigated in a human breast cancer cell line, T 47D. Studies have been carried out to assess the ability of various lectins and of the antibiotic tunicamycin to inhibit specific binding of calcitonin to the cells, to reduce cross-linking of photoactive calcitonin to a macromolecular receptor component and to influence calcitonin stimulation of cyclic AMP. Pre-incubation of cells with low concentrations of tunicamycin for 72 h resulted in a reduction of total specific binding by approx. 80% and a 40% reduction in calcitonin-stimulated adenylate cyclase; formation of the cross-linked receptor component was also inhibited. Wheat-germ lectin showed the most marked inhibition of total specific binding and cyclic AMP production. However, cross-linking of photoactive calcitonin to receptor component was totally inhibited by this lectin. Soya-bean lectin brought about very little reduction in total specific binding but had more profound effects on calcitonin-stimulated cyclic AMP production and cross-linking of photoactive calcitonin. Concanavalin A and lentil lectin showed some inhibition of all parameters. The data indicate that the calcitonin receptor in T 47D cells is associated with glycosyl moieties, the major contributors of which are N-acetyl-D-glucosamine residues, but N-acetyl-D-galactosamine and mannose residues are also associated.
D000262:Adenylyl Cyclases / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism*; D002116:Calcitonin / Q000378:metabolism; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006801:Humans; D037102:Lectins / Q000494:pharmacology; D046911:Macromolecular Substances; D014176:Protein Biosynthesis; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D014415:Tunicamycin / Q000494:pharmacology
D037102:Lectins; D046911:Macromolecular Substances; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; D014415:Tunicamycin; D002116:Calcitonin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases