Characterisation of high-affinity and low-affinity receptors for ciliary neurotrophic factor.
Ciliary neurotrophic factor (CNTF) supports the survival of a wide variety of neuronal cells in culture. To characterise the receptor(s) mediating the biological responses of CNTF we measured the binding of radiolabelled CNTF to chick sympathetic neurons and human neuroblastoma cells. Two distinct CNTF-binding sites with high and low affinity for the ligand were identified by steady-state binding experiments. Furthermore, two low-affinity binding sites could be discriminated on the basis of the dissociation rates. Cross-linking experiments showed that CNTF interacts with two proteins, one of 80 kDa and one of 140 kDa. The identity of the 80-kDa protein was determined by transient transfection experiments with the rat CNTF-binding protein CNTFR alpha while the properties of the 140-kDa protein correspond to those of gp130. Antisense experiments confirmed that CNTFR alpha is necessary for high affinity binding of 125I-CNTF and therefore a necessary subunit of the high-affinity receptor.
Huber
J
J
Max-Planck-Institute for Psychiatry, Department of Neurochemistry, Martinsried-Planegg, Germany.
Dittrich
F
F
Phelan
P
P
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002642:Chick Embryo; D020934:Ciliary Neurotrophic Factor; D003432:Cross-Linking Reagents; D018076:DNA, Complementary / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009414:Nerve Growth Factors / Q000302:isolation & purification / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D016376:Oligonucleotides, Antisense; D011869:Radioligand Assay; D051381:Rats; D020801:Receptor, Ciliary Neurotrophic Factor; D017978:Receptors, Growth Factor / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D013564:Sympathetic Nervous System; D014407:Tumor Cells, Cultured
D020934:Ciliary Neurotrophic Factor; D003432:Cross-Linking Reagents; D018076:DNA, Complementary; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D016376:Oligonucleotides, Antisense; D020801:Receptor, Ciliary Neurotrophic Factor; D017978:Receptors, Growth Factor; D011994:Recombinant Proteins