K. Shimoda et al., G-CSF INDUCES TYROSINE PHOSPHORYLATION OF THE JAK2 PROTEIN IN THE HUMAN MYELOID G-CSF RESPONSIVE AND PROLIFERATIVE CELLS, BUT NOT IN MATURENEUTROPHILS, Biochemical and biophysical research communications, 203(2), 1994, pp. 922-928
Granulocyte colony-stimulating factor (G-CSF) stimulates a rapid phosp
horylation on tyrosines of several proteins of Mr. 130, 100, 90, 70, 4
4 kd in human myeloid leukemia cell line cells, Kasumi-1, which respon
d to G-CSF to proliferate in vitro. In HL60 cells, only a 100 kd prote
in was phosphorylated, and no detectable phosphorylated proteins were
observed in neutrophils by the stimulation of G-CSF. Among these prote
ins, the 130 kd protein was immunoprecipitated by anti- JAK2 serum. Wh
ile JAK2 is a non receptor tyrosine kinase and is reported to be invol
ved in the signal transduction by various cytokines including growth h
ormone, erythropoietin, and granulocyte-macrophage colony-stimulating
factor/interleukin-3, it is strongly suggested that a signaling pathwa
y that relates to the cell proliferation triggered by G-CSF in immatur
e hematopoietic cells also involves JAK2. (C) 1994 Academic Press, Inc
.