ER quality control of immune receptors and regulators in plants.
Like in animals, cell surface and intracellular receptors mediate immune recognition of potential microbial intruders in plants. Membrane-localized pattern recognition receptors (PRRs) initiate immune responses upon perception of cognate microbe-associated molecular patterns (MAMPs). MAMP-triggered immunity provides a first line of defence that restricts the invasion and propagation of both adapted and non-adapted pathogens. The Leu-rich repeat (LRR) receptor protein kinases (RKs) define a major class of trans-membrane receptors in plants, of which some members are engaged in MAMP recognition and/or defence signalling. The endoplasmic reticulum (ER) quality control (QC) systems monitor N-glycosylation and folding states of the extracellular, ligand-binding LRR domains of LRR-RKs. Recent progress reveals a critical role of evolutionarily conserved ERQC components for different layers of plant immunity. N-glycosylation appears to play a role in ERQC fidelity rather than in ligand binding of LRR-RKs. Moreover, even closely related PRRs show receptor-specific requirements for N-glycosylation. These findings are reminiscent of the earlier defined function of the cytosolic chaperon complex for LRR domain-containing intracellular immune receptors. QC of the LRR domains might provide a basis not only for the maintenance but also for diversification of recognition specificities for immune receptors in plants.
Saijo
Yusuke
Y
Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany. saijo@mpiz-koeln.mpg.de <saijo@mpiz-koeln.mpg.de>
D000818:Animals; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D007155:Immunologic Factors / Q000378:metabolism*; D008954:Models, Biological; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000276:immunology* / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*
D007155:Immunologic Factors; D010940:Plant Proteins; D011971:Receptors, Immunologic