Protein tyrosine phosphatases: dephosphorylating the epidermal growth factor receptor.

Protein tyrosine phosphatases (PTPs) are a large and structurally diverse family of enzymes that are found in eukaryotes, prokaryotes, viruses, and plants. PTPs catalyse the dephosphorylation of tyrosyl phosphorylated proteins and can either antagonise or potentiate protein tyrosine kinase signalling. PTPs regulate fundamental cellular processes and have been implicated in the etiology and pathogenesis of various human diseases. The epidermal growth factor receptor (EGFR) is a widely distributed protein tyrosine kinase that regulates both normal development and plays a role in pathological conditions such as cancer. This review discusses the structure and function of PTPs and focuses on the PTPs that have been implicated in the dephosphorylation of the EGFR and the consequent suppression of EGFR signalling.