Interaction of Constitutive Photomorphogenesis 1 Protein with Protein-Tyrosine Phosphatase 1B Suppresses Protein-Tyrosine Phosphatase 1B Activity and Enhances Insulin Signaling

Recent studies reveal that COP1 suppresses the expression of gluconeogenetic genes and prohibits hepatic glucose production. To get more insight into COP1 in hepatic cells, we examined the impact of COP1 on insulin-responsive genes and insulin signaling. We found that COP1 increased the responsiveness of insulin-modulated genes to insulin in that it promoted the expression of insulin-induced genes and inhibited that of insulin-suppressed genes...