Investigating the Novel Role of a PM-Localized E3 Ligase in Pattern Triggered Immunity

Recognition of bacterial pathogens by plasma membrane (PM)-localized pattern recognition receptors (PRRs) initiates signaling resulting in pattern triggered immunity (PTI). Our lab identified a PM E3 ubiquitin ligase (E3L) rapidly phosphorylated during and required for PTI. Mutants lacking E3L show a loss of PTI resistance comparable to PRR receptor mutants, even though all other PTI responses are normal. Loss of E3L also suppresses the enhanced resistance in mutants of MAP Kinase Phosphatase 1 (mkp1), placing E3L genetically downstream of MKP1. In both cases, loss of PTI correlates with a failure to restrict the bacterial bacterial type III secretion system.