Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isoelectric focusing demonstrated that T cell growth factor (TCGF), T cell replacing factor (TRF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) derived from concanavalin A-stimulated T cell hybridomas and spleen cells are heterogeneous with respect to charge. The spleen cell-derived TCGF and TRF activities focused with isoelectric points (pI) between 3.5 and 6.5 whereas the range for GM-CSF activity was broader (pI, 3.5 to 8.0). The T cell hybridoma-derived activities were slightly more acidic. Neuraminidase treatment of both hybridoma 123 and spleen cell-derived material resulted in a major peak of each activity (TRF/TCGF pI, 4.9; GM-CSF pI, 4.7). Neuraminidase treatment of hybridoma T6-derived material resulted in peaks of TRF and TCGF around 6.0 as well as one around 5.0, suggesting that this charge heterogeneity was due to causes other than variations in the level of sialic acid on the relevant molecules. Tunicamycin-treated spleen cells or hybridoma 123 cells released biologically active TCGF, TRF, and GM-CSF. Each of these three activities from tunicamycin-treated spleen cells focused with pI around 5.0. A major fraction of TRF, TCGF, and GM-CSF activities bound to wheat-germ agglutinin. GM-CSF also bound to concanavalin A and lentil lectin. These results suggest that the molecules responsible for TCGF, TRF, and GM-SCF activities are glycosylated and that the observed heterogeneity in charge and lectin-binding characteristics is due in part to variable glycosylation. Glycosylation was not critical for any of the three biologic activities. No conclusive separation of TRF and TCGF activities was observed in these experiments although GM-CSF differed from TRF and TCGF in that it bound to Concanavalin A.
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PMID:Biochemical characterization of regulatory factors derived from T cell hybridomas and spleen cells. II. Evidence for glycosylation of T cell growth factor, T cell replacing factor, and granulocyte-macrophage colony-stimulating factor. 697 70

The alpha subunit of the receptor for human granulocyte-macrophage colony-stimulating factor (GM-CSF) is a glycoprotein containing 11 potential N-glycosylation sites in the extracellular domain. We examined the role of N-glycosylation on alpha subunit membrane localization and function. Tunicamycin, an N-glycosylation inhibitor, markedly inhibited GM-CSF binding, GM-CSF-induced deoxyglucose uptake, and protein tyrosine phosphorylation in HL-60(eos) cells but did not affect cell surface expression of the alpha subunit as detected by an anti-alpha subunit monoclonal antibody. In COS cells expressing the alpha subunit and treated with tunicamycin, N-unglycosylated alpha subunit was expressed and transported to the cell surface but was not capable of binding GM-CSF. High affinity binding in COS cells expressing both alpha and beta subunits was also blocked by tunicamycin treatment. These studies indicate that N-linked oligosaccharides are essential for alpha subunit ligand binding and signaling by the human GM-CSF receptor.
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PMID:N-glycosylation of the human granulocyte-macrophage colony-stimulating factor receptor alpha subunit is essential for ligand binding and signal transduction. 759 77