The Cytoplasmic Tyrosine Motifs in Full-Length Glycoprotein 130 Have Different Roles in IL-6 Signal Transduction

摘要: The function of the signal-transducing receptor subunit glycoprotein 130 (gp130) in IL-6-receptor complex has previously been studied using carboxyl-terminal deletion mutants or a truncated molecule approximately 60 membrane-proximal amino acids (containing box 1 and 2) linked to individual gp130 tyrosine motifs. However, redundancy motifs within cytoplasmic part neglected. Here we describe analysis residues context full-length protein IL-6 signaling as measured by STAT activation, acute phase induction, stimulation proliferation. Add-back containing only one have generated tested for their efficiency signal transduction. Our studies revealed that which described recruit proteins are not equivalent with respect potential activate factors gene promoters: two distal tyrosines, Tyr905 Tyr915, were more potent than Tyr767 Tyr814. Surprisingly, Tyr915 mediate promoter activation stronger wild-type all six residues. In contrast, Ba/F3 cells stably transfected add-back receptors sensitive IL-6-induced proliferation expressing other mutants. Thus, found contribute differentially transduction full- length protein.