Interleukin-6 triggers the association of its receptor with a possible signal transducer, gp130.
Interleukin-6 mediates pleiotropic functions in various types of cells through its specific receptor (IL-6-R), the cDNA of which has already been cloned. We report here that an 80 kd single polypeptide chain (IL-6-R) is involved in IL-6 binding and that IL-6 triggers the association of this receptor with a non-ligand-binding membrane glycoprotein, gp130. The association takes place at 37 degrees C within 5 min and is stable for at least 40 min in the presence of IL-6, but does not occur at 0 degree C. Human IL-6-R can associate with a murine gp130 homolog and is functional in murine cells. Mutant IL-6-R lacking the intracytoplasmic portion is functional, suggesting that the two polypeptide chains interact to involve their extracellular portion. In fact, a soluble IL-6-R lacking the transmembrane and intracytoplasmic domains can associate with gp130 in the presence of IL-6 and mediate its function. These findings indicate that the complex of IL-6 and IL-6-R can interact with a non-ligand-binding membrane glycoprotein, gp130, extracellularly and can provide the IL-6 signal.
Taga
T
T
Division of Immunology, Osaka University, Japan.
Hibi
M
M
Hirata
Y
Y
Yamasaki
K
K
Yasukawa
K
K
Matsuda
T
T
Hirano
T
T
Kishimoto
T
T
D000818:Animals; D003593:Cytoplasm / Q000502:physiology; D004252:DNA Mutational Analysis; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6; D007378:Interleukins / Q000502:physiology*; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000502:physiology*; D051379:Mice; D008970:Molecular Weight; D011233:Precipitin Tests; D011485:Protein Binding; D011971:Receptors, Immunologic / Q000502:physiology / Q000648:ultrastructure; D019947:Receptors, Interleukin-6; D012995:Solubility
D015850:Interleukin-6; D007378:Interleukins; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6