Essential roles for ID-1 motif of interleukin-4 receptor alpha chain in interleukin-4 signaling.
- Author:
Jonghee YOUN
1
;
Kyung Hee LEE
;
Woo Youl HWANG
;
Doo Jin PAIK
;
Ho Sam CHUNG
Author Information
1. Department of Anatomy & Cell Biology, College of Medicine, Hanyang University, Seoul, Korea. junghs@hanyang.ac.kr
- Publication Type:Original Article
- Keywords:
Interleukin-4;
Interleukin-4 receptor;
ID-1;
STAT-6
- MeSH:
Amino Acids, Acidic;
Asthma;
Clone Cells;
DNA, Complementary;
Electrophoretic Mobility Shift Assay;
Gene Expression;
Inflammation;
Interleukin-2;
Interleukin-4 Receptor alpha Subunit*;
Interleukin-4*;
Interleukins;
Janus Kinases;
Lymphoma;
Mutagenesis, Site-Directed;
Receptors, Interleukin-4;
RNA;
Sensitivity and Specificity;
Serine
- From:Journal of Asthma, Allergy and Clinical Immunology
2003;23(2):372-384
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Interleukin (IL)-4 is a pleiotropic cytokine that plays an important role in the pathogenesis of the allergic inflammation and asthma. Upon IL-4 receptor (IL-4R) engagement, a variety of signaling mediators, such as JAK kinases and STAT-6 are activated, leading to induction of IL-4 target gene expression including CD23 and germline C epsilon transcription. The function of a membrane-proximal domain of IL-4Ra, termed ID-1, remains to be characterized to date. OBJECTIVE: To assess whether the ID-1 domain mediates the induction of IL-4 target gene expression in a STAT-6-dependent manner. METHODS: The intracellular region of IL-4Ralpha was translationally fused to the extracellular region of IL-2Rbeta to provide ligand specificity to IL-2. Acidic amino acids and serine residues in the ID-1 domain of the chimeric receptor were substituted by site-directed mutagenesis. These receptor cDNAs were stably transfected to M12.4.1 murine B lymphoma cells. Following IL-2 stimulation, wild type and mutant clones for the ID-1 motif were subjected to FACS. RNA blotting and elecroporetic mobility shift assays to address the levels of CD23, germline C epsilon and STAT-6 inductions, respectively. RESULTS: ID-1 mutant clones were defective in gene induction of CD23 and germline C epsilon in response to IL-2 stimulation, as compared with wildtype clones. Moreover, IL-2-mediated STAT-6 activation was abolished in ID-1 mutant clones. CONCLUSION: These results demonstrate that the ID-1 domain of IL-4Ra is essential to induce IL-4 target gene expression through a STAT-6-dependent pathway.
