Figure 2.

PC-1 inhibition of IR β-subunit autophosphorylation in fibroblasts. A and B, Skin fibroblasts from the original patient with a 4-fold elevation of PC-1 were stimulated with either insulin (A) or IGF-I (B) for 5 min, and IR and IGF-IR autophosphorylation was measured by specific ELISAs. [Derived from Ref. 17.] C, 3T3 L1 mouse fibroblasts were transfected to overexpress human PC-1 4-fold. IR autophosphorylation in control 3T3 L1 and 3T3 L1 PC-1 fibroblasts was measured by specific IR ELISA.