Solution structure of the C-terminal domain of the ciliary neurotrophic factor (CNTF) receptor and ligand free associations among components of the CNTF receptor complex.
The functional receptor complex of ciliary neurotrophic factor (CNTF), a member of the gp130 family of cytokines, is composed of CNTF, the CNTF receptor alpha (CNTFR), gp130, and the leukemia inhibitory factor receptor (LIFR). However, the nature of the receptor-mediated interactions in this complex has not yet been resolved. To address this issue we have determined the solution structure of the C-terminal or BC domain of CNTFR and studied the interactions of CNTFR with LIFR and gp130. We reported previously that the membrane distal cytokine-binding domain (CBD1) of LIFR could interact in vitro with soluble CNTFR (sCNTFR) in the absence of CNTF. Here we show that the CBD of human gp130 can also bind in vitro to sCNTFR in the absence of CNTF. In addition, the gp130 CBD could compete with the LIFR CBD1 for the binding of sCNTFR. Substitution of residues in the gp130 CBD, the LIFR CBD1, and the CNTFR BC domain that are expected to be involved in receptor-receptor interactions significantly reduced their interactions. An NMR chemical shift perturbation study of the interaction between the BC domains of CNTFR and gp130 further mapped the interaction surface. These data suggest that both the gp130 CBD and the LIFR CBD1 interact with CNTFR in a similar way and provide insights into the nature of the CNTF receptor complex.
Man
David
D
Department of Biochemistry and Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
He
Wei
W
Sze
Kong Hung
KH
Gong
Ke
K
Smith
David K
DK
Zhu
Guang
G
Ip
Nancy Y
NY
D019943:Amino Acid Substitution; D015703:Antigens, CD / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D050822:Cytokine Receptor gp130; D006801:Humans; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020801:Receptor, Ciliary Neurotrophic Factor / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018121:Receptors, Cytokine / Q000737:chemistry* / Q000378:metabolism; D053606:Receptors, OSM-LIF; D012996:Solutions
D015703:Antigens, CD; C494199:IL6ST protein, human; C507840:LIFR protein, human; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008562:Membrane Glycoproteins; D020801:Receptor, Ciliary Neurotrophic Factor; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF; D012996:Solutions; D050822:Cytokine Receptor gp130