My interest is the study of the receptors and molecular mechanisms involved in signal transduction in cells. Models used for these investigations include rat basophilic leukemia cells and the cells involved in signal transduction of the chemical senses taste and smell. The goals of the RAST Section are to characterize receptors, their distribution, specificity and the mechanisms of signal transduction, desensitization and adaptation. We utilize cultured rat basophilic leukemia RBL-2H3 cells that are activated to secrete by aggregation of the high affinity IgE surface receptors. Emphasis has been on protein tyrosine phosphorylations that occur during cell activation.
Techniques combine the use of molecular and cell biological approaches.
The aggregating of the high affinity IgE receptor induces tyrosine phosphorylation of paxillin, a focal adhesion protein. Protein tyrosine phosphorylation as a mechanism of signalling in mast cells and basophils. Protein tyrosine phosphatase activity associates with the high affinity IgE receptor and dephosphorylates the receptor subunits, but not Lyn or Syk. Conformational changes in the protein tyrosine kinase p72syk by tyrosine phosphorylation or by binding immunoreceptor tyrosine-based activation motif peptides.