JAK2 IS CONSTITUTIVELY ASSOCIATED WITH C-KIT AND IS PHOSPHORYLATED INRESPONSE TO STEM-CELL FACTOR

Stem cell factor (SCF) interacts with the receptor tyrosine kinase c-K it and has potent effects on hematopoiesis, We have examined the role of JAK2 in the SCF signal transduction pathway. JAK2 and c-Kit were co nstitutively associated, and treatment with SCF resulted in rapid and transient tyrosine phosphorylation of JAK2, Incubation of cells with J AK2 antisense oligonucleotides resulted in significant decreases in SC F-induced proliferation, These data suggest that JAK2 plays a role in SCF-induced proliferation.