PC1 requires PTP1B to regulate IGF-1-dependent IGF-1R activation.

Cardiomyocytes were transfected with scrambled (Scr) or PC1 siRNA (siPC1), incubated for 24 h, and then stimulated with IGF-1 (10 nM) in the presence or absence of the phosphatase inhibitors Phos Stop (1X), Na3VO4 (1 mM) or CinnGEL (10 μM) for 5 min. Upper panels are representative Western blots of (A and B) phosphorylated IGF-1R (p-IGF1R) and IGF-1R, (C) phosphorylated Akt (p-Akt) and total Akt and (D) phosphorylated ERK1/2 (p-ERK1/2) and total ERK1/2. Lower panels show the (A-B) p-IGF-1R/IGF1R, (C) p-Akt/Akt, and (D) p-ERK1/2/ERK1/2 ratios. GAPDH was used as a loading control. Values are shown as mean ± SD (n = 3–6). *p&p&&p<0.01 vs. siPC1+ IGF-1.