Mapping mouse IL-13 binding regions using structure modeling, molecular docking, and high-density peptide microarray analysis.
Interleukin-13 is a Th2-associated cytokine responsible for many pathological responses in allergic asthma including mucus production, inflammation, and extracellular matrix remodeling. In addition, IL-13 is required for immunity to many helminth infections. IL-13 signals via the type-II IL-4 receptor, a heterodimeric receptor of IL-13Rα1 and IL-4Rα, which is also used by IL-4. IL-13 also binds to IL-13Rα2, but with much higher affinity than the type-II IL-4 receptor. Binding of IL-13 to IL-13Rα2 has been shown to attenuate IL-13 signaling through the type-II IL-4 receptor. However, molecular determinants that dictate the specificity and affinity of mouse IL-13 for the different receptors are largely unknown. Here, we used high-density overlapping peptide arrays, structural modeling, and molecular docking methods to map IL-13 binding sequences on its receptors. Predicted binding sequences on mouse IL-13Rα1 and IL-13Rα2 were in agreement with the reported human IL-13 receptor complex structures and site-directed mutational analysis. Novel structural differences were identified between IL-13 receptors, particularly at the IL-13 binding interface. Notably, additional binding sites were observed for IL-13 on IL-13Rα2. In addition, the identification of peptide sequences that are unique to IL-13Rα1 allowed us to generate a monoclonal antibody that selectively binds IL-13Rα1. Thus, high-density peptide arrays combined with molecular docking studies provide a novel, rapid, and reliable method to map cytokine-receptor interactions that may be used to generate signaling and decoy receptor-specific antagonists.
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
Satish K
SK
Madala
Michael A
MA
Dolan
Deepak
D
Sharma
Thirumalai R
TR
Ramalingam
Mark S
MS
Wilson
Margaret M
MM
Mentink-Kane
Daniel C
DC
Masison
Thomas A
TA
Wynn
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003198:Computer Simulation; D006801:Humans; D018793:Interleukin-13 / Q000378:metabolism*; D053661:Interleukin-13 Receptor alpha1 Subunit / Q000737:chemistry / Q000378:metabolism*; D053663:Interleukin-13 Receptor alpha2 Subunit / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D040081:Protein Array Analysis; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D040681:Structural Homology, Protein
D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D053663:Interleukin-13 Receptor alpha2 Subunit