Publication Abstract from PubMed
Interleukin 15 (IL-15) and IL-2, which promote the survival of memory CD8(+) T cells and regulatory T cells, respectively, bind receptor complexes that share beta- and gamma-signaling subunits. Receptor specificity is provided by unique, nonsignaling alpha-subunits. Whereas IL-2 receptor-alpha (IL-2Ralpha) is expressed together in cis with the beta- and gamma-subunits on T cells and B cells, IL-15Ralpha is expressed in trans on antigen-presenting cells. Here we present a 1.85-A crystal structure of the human IL-15-IL-15Ralpha complex. The structure provides insight into the molecular basis of the specificity of cytokine recognition and emphasizes the importance of water in generating this very high-affinity complex. Despite very low IL-15-IL-2 sequence homology and distinct receptor architecture, the topologies of the IL-15-IL-15Ralpha and IL-2-IL-2Ralpha complexes are very similar. Our data raise the possibility that IL-2, like IL-15, might be capable of being presented in trans in the context of its unique receptor alpha-chain.
Crystal structure of the IL-15-IL-15Ralpha complex, a cytokine-receptor unit presented in trans.,Chirifu M, Hayashi C, Nakamura T, Toma S, Shuto T, Kai H, Yamagata Y, Davis SJ, Ikemizu S Nat Immunol. 2007 Sep;8(9):1001-7. Epub 2007 Jul 22. PMID:17643103[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
