Phosphorylation and activation of the Jak-3 Janus kinase in response to interleukin-2.
Interleukin-2 is an autocrine growth factor for T cells which also activates other cells including B cells and natural killer cells. The subunits of the interleukin-2 receptor (IL-2R) lack intrinsic enzymatic activity, but protein tyrosine phosphorylation is a critical event following ligand binding and src family kinases, such as Lck, are known to be activated by IL-2 (refs 5-9). However, IL-2 signalling can occur in the absence of receptor interaction with Lck, suggesting that other protein tyrosine kinases might be important. Here we report that a new member of the Janus family of kinases (Jak-3) is coupled to the IL-2R in human peripheral blood T cells and natural killer cells.
Leukocyte Cell Biology Section, PRI/DynCorp, Frederick, Maryland.
J A
JA
Johnston
M
M
Kawamura
R A
RA
Kirken
Y Q
YQ
Chen
T B
TB
Blake
K
K
Shibuya
J R
JR
Ortaldo
D W
DW
McVicar
J J
JJ
O'Shea
D002460:Cell Line; D016207:Cytokines / Q000502:physiology; D004789:Enzyme Activation; D013006:Growth Hormone / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000502:physiology*; D053616:Janus Kinase 3; D007963:Leukocytes, Mononuclear / Q000201:enzymology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014407:Tumor Cells, Cultured
D016207:Cytokines; D007376:Interleukin-2; D013006:Growth Hormone; D011505:Protein-Tyrosine Kinases; C507933:JAK3 protein, human; D053616:Janus Kinase 3