The IL-10R2 binding hot spot on IL-22 is located on the N-terminal helix and is dependent on N-linked glycosylation.
IL-22 is a class 2 alpha-helical cytokine involved in the generation of inflammatory responses. These activities require IL-22 to engage the cell surface receptors IL-22R1 and the low-affinity signaling molecule IL-10R2. IL-10R2 also interacts with five other class 2 cytokines: IL-10, IL-26, and the interferon-like cytokines IL-28A, IL-28B, and IL-29. Here, we define the IL-10R2 binding site on IL-22 using surface plasmon resonance (SPR) and site-directed mutagenesis. Surprisingly, the binding hot spot on IL-22 includes asparagine 54 (N54), which is post-translationally modified by N-linked glycosylation. Further characterization of the glycosylation reveals that only a single fucosylated N-acetyl glucosamine on N54 is required for maximal IL-10R2 binding. Biological responses of IL-22 mutants measured in cell-based luciferase assays correlate with the in vitro SPR studies. Together, these data suggest that IL-22 activity may be modulated via changes in the glycosylation state of the ligand during inflammation.
Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Naomi J
NJ
Logsdon
Brandi C
BC
Jones
Jennifer C
JC
Allman
Lara
L
Izotova
Barbara
B
Schwartz
Sidney
S
Pestka
Mark R
MR
Walter
D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D004330:Drosophila / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006031:Glycosylation; D007378:Interleukins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D018123:Receptors, Interleukin / Q000378:metabolism*; D053701:Receptors, Interleukin-10; D020349:Surface Plasmon Resonance; D000097043:Interleukin-22
D000409:Alanine; D007378:Interleukins; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10; D000097043:Interleukin-22