Identification of regions within the third FnIII-like domain of the IL-5Ralpha involved in IL-5 interaction.
PE Czabotar, J Holland, CJ Sanderson
Cytokine | Published : 2000
Previously, two binding sites for interleukin 5 (IL-5) were identified on the IL-5 receptor alpha chain (IL-5Ralpha). They are located within the CD loop of the first fibronectin type III (FnIII)-like domain and the EF loop of the second FnIII-like domain. The first binding site was identified by exploiting the different abilities of human IL-5Ralpha (hIL-5Ralpha) and mouse IL-5Ralpha (mIL-5Ralpha) to bind hIL-5. Here we show that ovine IL-5 (oIL-5) has the ability to activate the hIL-5Ralpha but not the mIL-5Ralpha. By using chimeras of the mIL-5Ralpha and hIL-5Ralpha we demonstrate that residues within the first and third FnIII-like domains of mIL-5Ralpha are responsible for this lack of a..View full abstract