Expression of Plant Receptor-Like Kinase Leucine Rich Repeat Regions in E. Coli

Abstract

Plants respond to external stimuli through signal transduction pathways. An external signal binds the extracellular domain of a transmembrane receptor-like kinase (RLK) protein, and the signal is transmitted inside the cell through the RLK’s kinase domain. Two important plant RLKs are Arabidopsis CLV1 and rice Xa21. CLV1 regulates plant meristem growth and development, and Xa21 provides resistance to the pathogenic bacterium Xanthomonas oryzae. These functions are initiated by a peptide ligand binding a leucine-rich repeat (LRR) region in the extracellular domains of CLV1 and Xa21. Peptide phage display technology will be used to isolate additional peptide ligands that bind CLV1 and Xa21 LRRs. To this end, the DNAs encoding these LRRs are being cloned into vector pSUMO_Kan for soluble expression in E. coli as a fusion with SUMO protein. Fusion proteins will be isolated from E. coli cells by immobilized metal affinity chromatography.