Structure of and signal transduction through interleukin-4 and interleukin-13 receptors (review).
We have recently demonstrated that two different forms of IL-4R exist; classical or alternative. The classical IL-4R is predominantly expressed in hematopoietic cells and consist of IL-4R and IL-2Rgammac (gammac) chains. On the other hand, alternative form of IL-4R is predominantly expressed in non-hematopoietic cells and consists of IL-4R and IL-13Ralpha' chains. Moreover, the alternative form of IL-4R is also utilized as a functional component IL-13R complex. It has been shown that the phosphorylation and activation of JAK3 tyrosine kinase is crucial for IL-4 activation of STAT6 in hematopoietic cells. However, we have recently demonstrated that non-hematopoietic cells lack JAK3 expression. We also demonstrated that in these cells, STAT6 activation is mediated through JAK1 and JAK2 tyrosine kinases instead. Furthermore, our results show that IL-4 and IL-13 signals are transmitted through the alternative form of IL-4R in these cells. Thus, major differences exist between hematopoietic and non-hematopoietic cells with regard to structure and signal transduction through IL-4R and IL-13R systems.
Murata
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First Department of Internal Medicine, School of Medicine, Yokohama City University, Yokohama 236, Japan.
Obiri
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Puri
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D000818:Animals; D001773:Blood Cells / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D053661:Interleukin-13 Receptor alpha1 Subunit; D018123:Receptors, Interleukin / Q000502:physiology*; D053660:Receptors, Interleukin-13; D019948:Receptors, Interleukin-4 / Q000502:physiology*; D015398:Signal Transduction
C508181:IL13RA1 protein, human; D053661:Interleukin-13 Receptor alpha1 Subunit; D018123:Receptors, Interleukin; D053660:Receptors, Interleukin-13; D019948:Receptors, Interleukin-4