Molecular cloning and characterization of the rat liver IL-6 signal transducing molecule, gp130.
Interleukin-6 (IL-6) is a multifunctional cytokine that exerts its effects on different target cells by interacting with a specific receptor. This interaction leads to the association and activation of a second membrane glycoprotein, gp130, which is the IL-6 signal transducing molecule. The nucleotide sequence of gp130 from a human B-cell line has been reported. We report here the cloning and sequence analysis of the gp130 molecule derived from rat liver. Comparison of gp130 molecules from the different species and cell types reveals 78% overall amino acid homology and 94% identity in the growth factor signaling domain. Two gp130 mRNA species, a moderately abundant species of 7.5 kb and a lesser one of 9.0 kb, were present in rat hepatocytes. Ribonuclease protection analyses demonstrated the presence of gp130 mRNA in four different nontransformed cell types: hepatocytes, astrocytes, fibroblasts, and endothelial cells. The sequences between both gp130s in the different cell types are quite similar, supporting the prediction that the different responses initiated by IL-6 on different target cells are modulated by cell-specific proteins distal to the activated gp130 molecule.
Wang
Y
Y
Department of Cell Biology, University of Alabama, Birmingham 35294-0005.
Nesbitt
J E
JE
Fuentes
N L
NL
Fuller
G M
GM
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D017124:Conserved Sequence; D050822:Cytokine Receptor gp130; D004247:DNA; D015850:Interleukin-6 / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D011971:Receptors, Immunologic / Q000235:genetics; D019947:Receptors, Interleukin-6; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics*; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; C494201:Il6st protein, rat; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130; D004247:DNA