Common mechanisms activate plant guard receptors and TLR4

Abstract

In metazoans, the innate immune system uses Pattern Recognition Receptors to detect conserved microbial products, whereas in plants Guard Receptors detect virulence factors or activities encoded by pathogens. In a recent study, Williams and colleagues report that plant Guard receptors can be activated by a mechanism remarkably similar to that of mammalian Toll-like Receptor 4.

Figure 1

A common mechanism of plant NLR and mammalian TLR4 activation highlights similarities between the Guard and Pattern Recognition theories. (A) Depicted are the of TLR4-MD-2 and RRS1-RPS4 complexes that exist in uninfected mammalian or plant cells, respectively. The proteins that comprise these complexes are unrelated and occupy distinct subcellular sites. (B) A common mechanism of activation occurs between the TLR4 and RPS4 systems, which highlights a common theme between classically defined Guard receptors and PRRs.