PEST-domain enriched tyrosine phosphatase as a positive regulator of mast cell signaling

PEST-domain enriched tyrosine phosphatase (PEP) a non-receptor protein tyrosine phosphatase is expressed in mast cell. Lipid Fractionation studies showed that in PEP-/-BMMC there is increased accumulation of Csk compared to PEP+/+ BMMC which results in reduced Lyn activity and reduced degranulation. These findings together provide mechanistic explanations for the action of PEP as an important positive regulator of anaphylaxis in mice.