Tec protein tyrosine kinase is involved in the signaling mechanism of granulocyte colony-stimulating factor receptor.

Granulocyte colony-stimulating factor (G-CSF) is a critical cytokine to promote the growth, differentiation, and functional activation of myeloid cells. Despite its important roles, little is still understood how one cytokine can trigger such pleiotropic effects. By using mouse cell lines which can grow or differentiate in response to G-CSF, we investigated whether Tec protein tyrosine kinase is involved in either of the signaling pathways. Interestingly, Tec is shown to be tyrosine phosphorylated and activated by the G-CSF stimulation in both cell growth and differentiation mechanisms. Vav is also shown to be associated with Tec and tyrosine phosphorylated in response to G-CSF. Tec is a good candidate for protein-tyrosine kinases involved in both growth and differentiation mechanisms of myeloid cells.