N-GLYCOSYLATION OF THE HUMAN GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR-RECEPTOR ALPHA-SUBUNIT IS ESSENTIAL FOR LIGAND-BINDING AND SIGNAL-TRANSDUCTION
Dxh. Ding et al., N-GLYCOSYLATION OF THE HUMAN GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR-RECEPTOR ALPHA-SUBUNIT IS ESSENTIAL FOR LIGAND-BINDING AND SIGNAL-TRANSDUCTION, The Journal of biological chemistry, 270(41), 1995, pp. 24580-24584
The alpha subunit of the receptor for human granulocyte-macrophage col
ony-stimulating factor (GM-CSF) is a glycoprotein containing 11 potent
ial N-glycosylation sites in the extracellular domain, We examined the
role of N-glycosylation on alpha subunit membrane localization and fu
nction, Tunicamycin, an N-glycosylation inhibitor, markedly inhibited
GM-CSF binding, GM-CSF-induced deoxyglucose uptake, and protein tyrosi
ne 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 tre
ated with tunicamycin, N-unglycosylated alpha subunit was expressed an
d transported to the cell surface but was not capable of binding GM-CS
F. High affinity binding in COS cells expressing both alpha and beta s
ubunits was also blocked by tunicamycin treatment. These studies indic
ate that N-linked oligosaccharides are essential for alpha subunit lig
and binding and signaling by the human GM-CSF receptor.