The solution structure of the cytokine-binding domain of the common beta-chain of the receptors for granulocyte-macrophage colony-stimulating factor, interleukin-3 and interleukin-5.Mulhern, T.D., Lopez, A.F., D'Andrea, R.J., Gaunt, C., Vandeleur, L., Vadas, M.A., Booker, G.W., Bagley, C.J.
(2000) J.Mol.Biol. 297: 989-1001
- PubMed: 10736232
- DOI: 10.1006/jmbi.2000.3610
- PubMed Abstract:
- 1H and 15N Chemical Shift Assignments for Domain 4 of the Common Beta-Chain of the IL-3, IL-5 and GM-CSF Receptors
Mulhern, T.D.,Bagley, C.J.,Gaunt, C.,Lopez, A.F.,Vadas, M.A.,D'Andrea, R.J.,Booker, G.W.
(1999) J.Biomol.NMR 14: 281
The haemopoietic cytokines, granulocyte-macrophage colony-stimulating factor, interleukin-3 and interleukin-5 bind to cell-surface receptors comprising ligand-specific alpha-chains and a shared beta-chain. The beta-chain is the critical signalling su ...
The haemopoietic cytokines, granulocyte-macrophage colony-stimulating factor, interleukin-3 and interleukin-5 bind to cell-surface receptors comprising ligand-specific alpha-chains and a shared beta-chain. The beta-chain is the critical signalling subunit of the receptor and its fourth domain not only plays a critical role in interactions with ligands, hence in receptor activation, but also contains residues whose mutation can lead to ligand-independent activation of the receptor. We have determined the NMR solution structure of the isolated human fourth domain of the beta-chain. The protein has a fibronectin type III fold with a well-defined hydrophobic core and is stabilised by an extensive network of pi-cation interactions involving Trp and Arg side-chains, including two Trp residues outside the highly conserved Trp-Ser-Xaa-Trp-Ser motif (where Xaa is any amino acid) that is found in many cytokine receptors. Most of the residues implicated in factor-independent mutants localise to the rigid core of the domain or the pi-cation stack. The loops between the B and C, and the F and G strands, that contain residues important for interactions with cytokines, lie adjacent at the membrane-distal end of the domain, consistent with their being involved cooperatively in binding cytokines. The elucidation of the structure of the cytokine-binding domain of the beta-chain provides insight into the cytokine-dependent and factor-independent activation of the receptor.
Department of Biochemistry, University of Adelaide, Adelaide, 5005, Australia.