Regulation and turnover of the key immune signaling kinase BIK1
Plants have evolved sophisticated mechanisms for dealing with pathogen stressors. Conserved microbial patterns are perceived by receptors at the plant plasma membrane, inducing a signaling cascade which culminates in a robust immune response. Although essential for survival, uncontrolled immune responses can lead to severe fitness costs in the plant, and therefore immune signaling must be tightly regulated. One aspect of this regulation involves the maintenance of optimal levels of the immune signaling kinase, BIK1. The calcium-dependent protein kinase, CPK28, was previously found to contribute to its turnover via the 26S proteasome. We have since identified that the plant-Ubox proteins, PUB25 and PUB26 are the E3 ligases that contribute to BIK1 turnover through phosphorylation by CPK28. My MSc project has involved the use of various genetic and biochemical tools to further tease apart the fine mechanisms by which CPK28 and PUB25/26 function as a module to maintain optimal BIK1 levels, and thus plant immune homeostasis.
11:30-12:30 BioSci Rm. 3110