System Maintenance Notice

Please note that maintenance work is scheduled between 4 AM and 5 AM - CET. During this time, you may experience reduced performance. Thanks for your patience.

Publications

Journal Article Research Support, Non-U.S. Gov't Ppublish 14 citations

PubMed: 35997573 DOI: 10.1093/plphys/kiac391

Fungal dual-domain LysM effectors undergo chitin-induced intermolecular, and not intramolecular, dimerization.

Plant Physiol 190(3):2033-2044

Authors: Hui Tian, Gabriel L Fiorin, Anja Kombrink, Jeroen R Mesters, Bart P H J Thomma

Affiliations

  • University of Cologne, Institute for Plant Sciences, 50674 Cologne, Germany. Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands.
  • Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands.
  • Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
  • University of Cologne, Institute for Plant Sciences, 50674 Cologne, Germany.
  • University of Cologne, Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), 50674 Cologne, Germany.

Abstract

Chitin is a homopolymer of β-(1,4)-linked N-acetyl-D-glucosamine (GlcNAc) and a major structural component of fungal cell walls. In plants, chitin acts as a microbe-associated molecular pattern (MAMP) that is recognized by lysin motif (LysM)-containing plant cell surface-localized pattern recognition receptors (PRRs) that activate a plethora of downstream immune responses. To deregulate chitin-induced plant immunity and successfully establish infection, many fungal pathogens secrete LysM domain-containing effector proteins during host colonization. The LysM effector Ecp6 from the tomato (Solanum lycopersicum) leaf mold fungus Cladosporium fulvum can outcompete plant PRRs for chitin binding because two of its three LysM domains cooperate to form a composite groove with ultra-high (pM) chitin-binding affinity. However, most functionally characterized LysM effectors contain only two LysMs, including Magnaporthe oryzae MoSlp1, Verticillium dahliae Vd2LysM, and Colletotrichum higginsianum ChElp1 and ChElp2. Here, we performed modeling, structural, and functional analyses to investigate whether such dual-domain LysM effectors can also form ultra-high chitin-binding affinity grooves through intramolecular LysM dimerization. However, our study suggests that intramolecular LysM dimerization does not occur. Rather, our data support the occurrence of intermolecular LysM dimerization for these effectors, associated with a substantially lower chitin binding affinity than monitored for Ecp6. Interestingly, the intermolecular LysM dimerization allows for the formation of polymeric complexes in the presence of chitin. Possibly, such polymers may precipitate at infection sites to eliminate chitin oligomers, and thus suppress the activation of chitin-induced plant immunity.

MeSH

Infections, Cells, Chitin, Acetylglucosamine, Plant Immunity

Cited by