Functions of protein tyrosine phosphatases

Protein tyrosine phosphorylation is a dynamic and low-abundant posttranslational modification that plays critical roles in many biological processes including cell growth, proliferation, and differentiation. The appropriate level of protein tyrosine phosphorylation in vivo is maintained by both protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), while either up- or down-regulation can lead to various diseases such as cancer, diabetes, etc. Historically, studies on PTPs have lagged behind those of PTKs because most scientists believed that PTPs simply reverse modification caused by PTKs. However, more biochemical, genetic, and structural data have recently supported that PTPs also participate actively in regulation of tyrosine phosphorylation.

My laboratory is interested in studying in vivo functions of PTPs with a wide range of techniques, including synthetic chemistry, molecular biology, protein biochemistry, and proteomic tools. We will develop novel chemical approaches that can detect, inhibit, or trap a specific PTP from its native milieu. These methods will not only help us to investigate physiological roles of PTPs in cellular signal transduction and their defects in various diseases, but also provide new tools for identification of novel targets for drug discovery.