Identification of the insulin receptor in undifferentiated and differentiated NB-15 mouse neuroblastoma cells by affinity labeling.
Plasma membranes prepared from clonal NB-15 mouse neuroblastoma cells were sequentially incubated with 125I-labeled insulin (10 nM) and the bifunctional cross-linking agent disuccinimidyl suberate. This treatment resulted in the cross-linking of 125I-labeled insulin to a polypeptide that gave an apparent Mr of 135 000 on a sodium dodecyl sulfate-polyacrylamide gel electrophoresed in the presence of 10% beta-mercaptoethanol. Affinity labeling of this polypeptide was inhibited by the presence of 5 microM unlabeled insulin, but not by 1 microM unlabeled nerve growth factor. Using the same affinity labeling technique, 125I-labeled nerve growth factor (1 nM) did not label any polypeptide appreciably in the plasma membranes of NB-15 cells but labeled an Mr 145 000 and an Mr 115 000 species in PC-12 rat pheochromocytoma cells. The number of insulin binding sites per cell in the intact differentiated NB-15 mouse neuroblastoma cells was approx. 6-fold greater than that in the undifferentiated NB-15 mouse neuroblastoma cells as measured by specific binding assay, suggesting an increase of the number of insulin receptors in NB-15 mouse neuroblastoma cells during differentiation.
D000310:Adrenal Gland Neoplasms / Q000032:analysis; D000345:Affinity Labels / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D002462:Cell Membrane / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D007328:Insulin / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D008970:Molecular Weight; D009447:Neuroblastoma / Q000032:analysis*; D010673:Pheochromocytoma / Q000032:analysis; D011972:Receptor, Insulin / Q000032:analysis*; D013388:Succinimides / Q000494:pharmacology
D000345:Affinity Labels; D007328:Insulin; D013388:Succinimides; D011972:Receptor, Insulin; C019358:disuccinimidyl suberate