Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P14784 (IL-2 receptor)
 3,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis and intracellular sorting of the interleukin-2 (IL-2) receptor were studied with a line of mutant Chinese hamster ovary (CHO) cells with a reversible defect in protein O glycosylation. Under normal culture conditions the mutant ldlD cannot add N-acetylgalactosamine (Ga1NAc) to proteins. Ga1NAc is the first sugar of mucin-type O-linked oligosaccharides attached to protein. This O-glycosylation defect is rapidly corrected when Ga1NAc is added to the culture mediu. An expression vector for the p55 human IL-2 receptor was transfected into wild-type CHO and ldlD cells and the structure, stability, and cell surface expression of the receptor were examined by immunoprecipitation and antibody-binding assays. Essentially all of the mature form of the normally glycosylated IL-2 receptor in both wild-type CHO cells and ldlD cells incubated with Ga1NAc was expressed on the cell surface. The stability of O-linked carbohydrate-deficient (Od) IL-2 receptors (in ldlD cells without Ga1NAc) was normal; however, missorting of the Od receptors resulted in very little cell surface expression. The sialidase sensitivity and endoglycosidase H resistance of mature Od IL-2 receptors suggest that Od receptor missorting occurred in or beyond the trans Golgi apparatus. The abnormal sorting of the Od IL-2 receptor is compared with the O-glycosylation dependence of the surface expression and stability of the low-density lipoprotein receptor, decay-accelerating factor, and the major antigen envelope protein of Epstein-Barr virus.
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PMID:Abnormal intracellular sorting of O-linked carbohydrate-deficient interleukin-2 receptors. 326 79

Interleukin-2 (IL-2) specifically recognizes high-mannose type glycans with five or six mannosyl residues. To determine whether the carbohydrate recognition activity of IL-2 contributes to its physiological activity, the inhibitory effects of high-mannose type glycans on IL-2-dependent CTLL-2 cell proliferation were investigated. Man(5)GlcNAc(2)Asn added to CTLL-2 cell cultures inhibited not only phosphorylation of tyrosine kinases but also IL-2-dependent cell proliferation. We found that a complex of IL-2, IL-2 receptor alpha, beta, gamma subunits, and tyrosine kinases was formed in rhIL-2-stimulated CTLL-2 cells. Among the components of this complex, only the IL-2 receptor alpha subunit was stained with Galanthus nivalis agglutinin which specifically recognizes high-mannose type glycans. This staining was diminished after digestion of the glycans with endo-beta-N-acetylglucosaminidase H or D, suggesting that at least a N-glycan containing Man(5)GlcNAc(2) is linked to the extracellular portion of the IL-2 receptor alpha subunit. Our findings indicate that IL-2 binds the IL-2 receptor alpha subunit through Man(5)GlcNAc(2) and a specific peptide sequence on the surface of CTLL-2 cells. When IL-2 binds to the IL-2Ralpha subunit, this may trigger formation of the high affinity complex of IL-2-IL-2Ralpha, -beta, and -gamma subunits, leading to cellular signaling.
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PMID:Interleukin-2 carbohydrate recognition modulates CTLL-2 cell proliferation. 1107 50