[Granulocyte-macrophage colony-stimulating factor and erythropoietin induce tyrosine phosphorylation and activation of JAK2].
OBJECTIVE
In order to identify the tyrosine kinase (s) that may associate with cell proliferation.


METHODS
GM-CSF/Epo responsive cell UT-7 and Epo responsive cell UT-7/Epo were used for study of tyrosine phosphorylation.


RESULTS
The addition of GM CSF and/or Epo to the responsive cells induced rapid tyrosine phosphorylations of 145000, 130000, 80000 and 40000 cellular proteins. The tyrosine phosphorylated 130000 protein was identified as JAK2, a non receptor tyrosine kinase. GM CSF and Epo also activated its tyrosine kinase activity. Tyrosine phosphorylation and activation of JAK2 only occurred in GM-CSF and/or Epo-responsive cells.


CONCLUSIONS
JAK2 signal transduction pathway may play an important role in regulating the proliferation of hematopoietic cells induced by GM-CSF and Epo.
Ren
H
H
Institute of Hematology, People's Hospital, Beijing Medical University, Beijing 100044.
Lu
D
D
D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000187:drug effects; D004921:Erythropoietin / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D053614:Janus Kinase 2 / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D014443:Tyrosine / Q000378:metabolism*
D004921:Erythropoietin; D014443:Tyrosine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D053614:Janus Kinase 2