Reconstitution of two isoforms of the human interleukin-11 receptor and comparison of their functional properties

Long-term stable Ba/F3 transfectants (B13R alpha 1 and B13R alpha 2) expressing two isoforms of the human IL-11R alpha receptor (alpha 1 full length or alpha 2 lacking the cytoplasmic domain) in combination with human gp130 were established, IL-11R alpha 1 and IL-11R alpha 2 were each expressed and detected as three bands upon Western blot analysis, with apparent molecular masses in agreement with those of the polypeptide backbone (47 and 44 kDa, respectively) with no, one or two N-linked sugars, B13R alpha 1 and B13R alpha 2 bound IL-11-thioredoxin with similar efficiencies and proliferated with superimposable dose-response curves to IL-11, demonstrating that the intracellular domain of IL-11R alpha has no significant contribution on ligand binding and signaling, Analysis of a set of anti-human gp130 mAbs confirmed the similar responsiveness of B13R alpha 1 and B13R alpha 2 transfectants. (C) 1997 Federation of European Biochemical Societies.