Protein tyrosine phosphatases: molecular switches in metabolism and diabetes

Protein tyrosine phosphatases (PTPs) are a large family of enzymes that generally oppose the actions of protein tyrosine kinases (PTKs). Genetic polymorphisms for particular PTPs are associated with altered risk of both type 1 diabetes (T1D) and type 2 diabetes (T2D). Moreover, recent evidence suggests that PTPs play crucial roles in metabolism. They can act as regulators of liver homeostasis, food intake, or immune-mediated pancreatic beta cell death. In this review we describe the mechanisms by which different members of the non-receptor PTP (PTPN) family influence metabolic physiology. This 'metabolic job' of PTPs is discussed in depth and the role of these proteins in different cell types compared. Understanding the pathways regulated by PTPs will provide novel therapeutic strategies for the treatment of diabetes.