A 70-kDa protein facilitates interleukin-4 signal transduction in the absence of the common gamma receptor chain.
Interleukin-4 signal transduction (and activation of STAT 6) is known to be mediated via its binding to a p140 receptor chain and the common gamma chain (gamma c). In non-activated monocytes, neither the gamma c nor its associated signal transducing molecule, Jak3, is expressed. We nevertheless show that IL-4 can initiate the tyrosine phosphorylation and DNA binding of STAT 6 in these cells. We present evidence for an additional 70 kDa IL-4 receptor chain which mediates the tyrosine phosphorylation of STAT 6 via Jak2, and suggest that this is the means by which IL-4 can signal in cells lacking the gamma c.
Dawson
C H
CH
Institute for Cancer Studies, University of Sheffield Medical School, United Kingdom.
Brown
B L
BL
Dobson
P R
PR
D015703:Antigens, CD / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D015847:Interleukin-4 / Q000378:metabolism*; D053616:Janus Kinase 3; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D018123:Receptors, Interleukin / Q000378:metabolism*; D019948:Receptors, Interleukin-4; D015398:Signal Transduction
D015703:Antigens, CD; D018123:Receptors, Interleukin; D019948:Receptors, Interleukin-4; D015847:Interleukin-4; D011505:Protein-Tyrosine Kinases; C507933:JAK3 protein, human; D053616:Janus Kinase 3