Seeing like a plant: immune recognition and signaling by cell surface receptors

Plants sense extracellular cues through several hundred cell surface receptors. The most rapidly evolving group of receptors is the leucine-rich repeat receptor-like proteins (RLPs), which transduce immune signals as a bipartite receptor complex with the adapter SOBIR1. In recent years many new examples of immunogenic patterns detected by specific RLPs have been described, highlighting their versatility as immune sensing modules. I will discuss unique features of the RLP family that mediate recognition and signaling functions. For recognition, RLPs encode an extracellular island domain, which allosterically couples ligand binding to co-receptor recruitment. For signaling, RLPs lack a kinase domain typical of most receptors, but the short cytoplasmic tail domain can encode signaling through different defense pathways. For both recognition and signaling functions, I will describe new insights from our study of Inceptin Receptor (INR), which detects caterpillar-derived peptide elicitors and evolved 28 mya in a single subtribe of legumes. Since both island and tail domains are small (~10-60 aa) shared features of all RLPs, they may represent modular, editable handles to engineer plant immune systems.

Speaker:Adam Steinbrenner, University of Washington