Putative plant membrane receptor shedding: Case study on RLK902
J. SERNESTRAND (1), M. Berens (2), R. van der Hoorn (3), T. Colby (2), P. Huesgen (1) (1) Juelich Forschungszentrum, Germany; (2) Max planck institute for plant breeding research, Germany; (3) Department of Plant Sciences, University of Oxford, United Kingdom

Living organisms respond to their outside environment through cell surface-localized receptor-like kinases (RLKs). In animals, RLK signal perception and transduction frequently involves shedding of the extracellular receptor domain through proteolytic enzymes termed shedases. The release of extracellular soluble ligand-binding domain and/or intracellular cytoplasmic domain can associate with and/or modulate the activity of extracellular and cytoplasmic/nuclear proteins, respectively. Shedding as a proteolytic posttranslational modification has important implications in many cellular and physiological processes in development, homeostasis, inflammation and pathology; however, this is poorly understood in plants. Interestingly, our protein kinase profiling platform using AcATP (and AcGTP) probes has revealed possible receptor shedding of three homologous RLKs (At3g02880, At5g16590 and RLK902). To further investigate this, and to monitor expression and subsequent processing, full length RLK902 fused to an N-terminal Myc tag and C-terminal YFP tag was overexpressed in N. benthamiana leaves. It was observed that RLK902 accumulates in the plasma membrane. However, it is processed in vivo through time, with full length RLK902 detected at two days post infiltration (dpi) and processed products observed from three to five dpi. Mutation of the conserved residues K393, K492 and D508 in the intracellular kinase domain did not affect RLK902 processing.

Abstract Number: P17-606
Session Type: Poster