GM-CSF binding to its receptor induces oligomerisation of the common beta-subunit
Date
2001
Authors
Mc Clure, B.
Woodcock, J.
Harrison-Findik, D.
Lopez, A.
D'Andrea, R.
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Advisors
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Volume Title
Type:
Journal article
Citation
Cytokine, 2001; 13(4):240-243
Statement of Responsibility
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Abstract
The stoichiometry of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor complex is still unresolved. We have utilised a sensitive, functional assay for receptor homodimerisation to show that GM-CSF induces dimerisation of the common signalling subunit, hbeta(c). We generated a chimeric cytokine receptor in which the extracellular and transmembrane domains of hbeta(c)are fused to the cytoplasmic domain of erythropoietin receptor (EPO-R). Given that to induce EPO-R activation and mitogenic signalling there is a requirement for formation of a specific homodimeric complex, we reasoned that the cytoplasmic domain of EPO-R could be utilised as a highly sensitive reporter for functional homodimer formation. We show that, in the presence of a cytoplasmically truncated GM-CSF alpha-subunit, the hbetac-EPO receptor chimera transduces a mitogenic signal in BaF-B03 in response to GM-CSF. This is consistent with formation of a hbeta(c)homodimer following GM-CSF binding and implies that ligand stimulation induces formation of a higher order complex that contains the hbeta(c)homodimer.