Growth signal erythropoietin activates the same tyrosine kinases as interleukin 3, but activates only one tyrosine kinase as differentiation signal.
By Western blotting with anti-phosphotyrosine-specific antibody, we demonstrated that both erythropoietin (Epo) and interleukin 3 (IL3) induce rapid and transient tyrosine phosphorylation of a common set of proteins of 45, 55, 69, 87, 90, 95 and 160 KDa as a growth signal in Epo- and IL3-dependent FD-M6 cells. In contrast, only two proteins of 87 and 90 KDa were transiently phosphorylated in Epo-induced erythroid differentiation of SKT6 cells. Furthermore, no tyrosine phosphorylation was observed in dimethyl sulfoxide-induced differentiation of SKT6 cells. Taken together with other observations, these results indicate that Epo, IL3 and GM-CSF activate the same tyrosine protein kinases as growth signal and that Epo-induced differentiation signal uses only a part of the tyrosine kinase pathway.
Kuramochi
S
S
Tsukuba Life Science Center, Institute of Physical and Chemical Research (RIKEN), Ibaraki, Japan.
Chiba
T
T
Amanuma
H
H
Tojo
A
A
Todokoro
K
K
D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004921:Erythropoietin / Q000494:pharmacology*; D007377:Interleukin-3 / Q000494:pharmacology*; D007700:Kinetics; D007942:Leukemia, Experimental; D051379:Mice; D008970:Molecular Weight; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D007377:Interleukin-3; D010750:Phosphoproteins; D004921:Erythropoietin; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases