Project Details
Projekt
Functional characterisation of a novel semi-dominant mutant allele of the "Chitin Elicitor Receptor-like Kinase" CERK1
Applicant
Professor Dr. Volker Lipka
Subject Area
Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
Term
from 2009 to 2014
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 146209784
This project focuses on a novel molecular mechanism that controls cell death execution and containment in plant cells in response to pathogen infection. We have previously identified a novel semi-dominant mutation in the CERK1 gene of Arabidopsis (cerk1-4), which confers enhanced resistance to infection by several biotrophic powdery mildew fungi. Significantly, this resistance is correlated with a deregulated spreading cell death response. This indicates that the plasma-membrane localised receptor-like kinase CERK1, apart from its function in the perception of the fungal PAMP chitin (and a yet unidentified bacterial danger signal) is a regulator of pathogen-induced cell death. Interestingly, intrinsic kinase activity is not required for the cerk1-4 mutant phenotype. Instead, we have shown that aberrant cell death containment in the cerk1-4 mutant correlates with lack of a soluble 33 kDa derivative of the CERK1 protein, which represents the N-terminal ectodomain. In wild-type plants, this ectodomain fragment localises to the apoplast and appears to be the product of controlled enzymatic proteolysis. In vertebrates, tightly regulated shedding of the ectodomain of trans-membrane proteins is a well-established post-translational regulatory mechanism. To our knowledge, ectodomain shedding has not yet been described for plant proteins. The cerk1-4 mutant allele thus represents an excellent entree into understanding ectodomain shedding of plant transmembrane proteins in general and how this regulatory mechanism is involved in plant cell death containment.
DFG Programme
Priority Programmes
