The Size of Activating and Inhibitory Killer Ig-like Receptor Nanoclusters Is Controlled by the Transmembrane Sequence and Affects Signaling

• Published in: Cell reports (Cambridge) Vol. 15; no. 9; pp. 1957 - 1972
• Main Authors: Oszmiana, Anna, Williamson, David J., Cordoba, Shaun-Paul, Morgan, David J., Kennedy, Philippa R., Stacey, Kevin, Davis, Daniel M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 31-05-2016; Cell Press; Elsevier
• Subjects: Adaptor Proteins, Signal Transducing - metabolism; Amino Acid Substitution; Cell Line; Cell Membrane - metabolism; Clone Cells; Humans; Killer Cells, Natural - metabolism; Membrane Proteins - metabolism; Nanoparticles - chemistry; Phosphorylation; Protein Binding; Protein Tyrosine Phosphatase, Non-Receptor Type 6 - metabolism; Receptors, KIR - metabolism; Receptors, KIR2DL1 - metabolism; Signal Transduction; ZAP-70 Protein-Tyrosine Kinase - metabolism
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2016.04.075

Super-resolution microscopy has revealed that immune cell receptors are organized in nanoscale clusters at cell surfaces and immune synapses. However, mechanisms and functions for this nanoscale organization remain unclear. Here, we used super-resolution microscopy to compare the surface organization of paired killer Ig-like receptors (KIR), KIR2DL1 and KIR2DS1, on human primary natural killer cells and cell lines. Activating KIR2DS1 assembled in clusters two-fold larger than its inhibitory counterpart KIR2DL1. Site-directed mutagenesis established that the size of nanoclusters is controlled by transmembrane amino acid 233, a lysine in KIR2DS1. Super-resolution microscopy also revealed two ways in which the nanoscale clustering of KIR affects signaling. First, KIR2DS1 and DAP12 nanoclusters are juxtaposed in the resting cell state but coalesce upon receptor ligation. Second, quantitative super-resolution microscopy revealed that phosphorylation of the kinase ZAP-70 or phosphatase SHP-1 is favored in larger KIR nanoclusters. Thus, the size of KIR nanoclusters depends on the transmembrane sequence and affects downstream signaling.
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•Activating and inhibitory NK cell receptors have a distinct nanoscale organization•The transmembrane sequence of KIR controls their nanoscale organization•Nanoclusters of KIR2DS1 and its adaptor are juxtaposed but mix upon activation•Phosphorylation of ZAP-70 or SHP-1 is favored in larger receptor nanoclusters
Oszmiana et al. use different super-resolution microscopy techniques to compare the nanoscale organization of paired activating and inhibitory receptors at the human NK cell surface. They show that the size of receptor nanoclusters is controlled by the transmembrane sequence and establish that nanocluster size affects the strength of receptor signaling.