Low molecular weight protein tyrosine phosphatase and insulin signal transduction

The low molecular weight protein tyrosine phosphatase (LMPTP) is highly expressed in insulin-responsive tissues. LMPTP has been shown to play a role in glucose and lipid metabolism and its genetic polymorphism is associated with obesity and diabetes. Both in vitro and in vivo studies have been performed to demonstrate negative regulating effect of LMPTP on insulin signal transduction. In this study, my findings support the idea that LMPTP is a critical regulator of insulin signaling. LMPTP targets the activation segment of the insulin receptor and dephosphorylates it directly. Between the two isoforms of LMPTP, isoform 1 (IF1) seems to be catalytically more active than isoform 2 (IF2) on the insulin receptor.