title: Glucose starvation alters insulin but not IGF-I binding to Chinese hamster ovary (CHO) cells.
abstract: The pattern of cellular protein glycosylation can be altered in CHO cells by glucose starvation. When wild type CHO cells are deprived of glucose, 125I-insulin binding increases from a B/F of 0.033 +/- 0.004 to 0.063 +/- 0.011, due to an increase in receptor affinity. The already elevated insulin binding to mutant B4-2-1 CHO cells, whose genetic defect causes abnormal glycosylation mimicking the pattern seen in the glucose starved normal cells, is not affected by glucose starvation. In neither cell line is 125I-IGF-I binding affected by glucose starvation. These data support the hypothesis that abnormal glycosylation can alter insulin binding to its receptor. Furthermore, there is a striking difference in the susceptibility of IGF-I and insulin receptors to alterations in glycosylation.
mesh_terms: D000818:Animals; D002460:Cell Line; D005947:Glucose / Q000502:physiology*; D007328:Insulin / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D009154:Mutation; D011869:Radioligand Assay; D011972:Receptor, Insulin / Q000378:metabolism*; D013002:Somatomedins / Q000378:metabolism*
chemical_list: D007328:Insulin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin; D005947:Glucose