Identification of the calcitonin receptor by chemical cross-linking and photoaffinity labeling in human cancer cell lines.
Two methods have been used to covalently cross-link [125I]-salmon calcitonin to its receptor on a human lung carcinoma cell line, BEN, and the human breast cancer cell lines T47D and MCF 7. The first method was to use a specific photoaffinity derivative of salmon calcitonin and the second employed the chemical cross-linker, disuccinimidyl suberate. In both cases a cross-linked component of approximate molecular weight 80-90,000 on BEN cells was identified by polyacrylamide gel electrophoresis. This is consistent with the size of the cross-linked component found on T47D breast cancer cells using the photoactive salmon calcitonin as described in previous work. Disuccinimidyl suberate was unable to cross-link [125I]-salmon calcitonin either on T47D or MCF cells. However, photoactive salmon calcitonin cross-linked to a component of approximately 80-90,000 Mr on the MCF 7 cells. Thus, whereas the photoactive salmon calcitonin could cross-link a similar receptor component in all cell lines, the ability of disuccinimidyl suberate to do so was apparently cell specific. These data confirm that the calcitonin receptor comprises a component of approximately 85,000 Mr in cell lines examined thus far.
Moseley
J M
JM
University of Melbourne, Department of Medicine, Repatriation General Hospital, Heidelberg, Victoria, Australia.
Smith
P
P
Martin
T J
TJ
D000345:Affinity Labels; D001943:Breast Neoplasms / Q000032:analysis; D002116:Calcitonin; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008175:Lung Neoplasms / Q000032:analysis; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000032:analysis*; D014407:Tumor Cells, Cultured / Q000032:analysis*
D000345:Affinity Labels; D003432:Cross-Linking Reagents; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; D002116:Calcitonin