Michel L. Tremblay

Protein Tyrosine Phosphatases (PTPases) have been implicated in a variety of cellular processes such as cell growth, differentiation, and cancer. The nature of these enzymes suggests that they may be involved in cancer by acting either as anti-oncogenes or as oncogenes themselves. There is also evidence to suggest that PTPases are involved in mammalian development.

Our research interest has focused on three recently cloned enzymes and their relationship to mouse development and cancer. One of these PTPases, termed MPTP, is a ubiquitously expressed PTPase which localizes to the cell nucleus and may play a role in cell cycle events. MPTP-PEST is a ubiquitously expressed cytosolic enzyme which has been implicated in intracellular signal transduction. PTP NU-3 is a neuronal-cell specific PTPase which belongs to the receptor-type family of enzymes and is thought to play a role in neurogenesis by interacting with the extracellular matrix.

Our lab employs a variety of tools in the analysis of these PTPases. These include: cloning and identification of tissue specific and developmentally regulated PTPases; identification of in vivo substrates, associated proteins, and extracellular ligands; creation of temperature sensitive enzymes and cell lines; and the analysis of the gene expression pattern during mouse development. Together with transgenic and "knockout" mouse technology, these tools allow us to asses the role of these genes during mouse development as well as cellular events involved in cancer.