title: Elicitin-Induced Distal Systemic Resistance in Plants is Mediated Through the Protein-Protein Interactions Influenced by Selected Lysine Residues.
abstract: Elicitins are a family of small proteins with sterol-binding activity that are secreted by Phytophthora and Pythium sp. classified as oomycete PAMPs. Although α- and β-elicitins bind with the same affinity to one high affinity binding site on the plasma membrane, β-elicitins (possessing 6-7 lysine residues) are generally 50- to 100-fold more active at inducing distal HR and systemic resistance than the α-isoforms (with only 1-3 lysine residues). To examine the role of lysine residues in elicitin biological activity, we employed site-directed mutagenesis to prepare a series of β-elicitin cryptogein variants with mutations on specific lysine residues. In contrast to direct infiltration of protein into leaves, application to the stem revealed a rough correlation between protein's charge and biological activity, resulting in protection against Phytophthora parasitica. A detailed analysis of proteins' movement in plants showed no substantial differences in distribution through phloem indicating differences in consequent apoplastic or symplastic transport. In this process, an important role of homodimer formation together with the ability to form a heterodimer with potential partner represented by endogenous plants LTPs is suggested. Our work demonstrates a key role of selected lysine residues in these interactions and stresses the importance of processes preceding elicitin recognition responsible for induction of distal systemic resistance.
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Uhlíková
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Obořil
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Klempová
authors.affiliation: Research Group Proteomics, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Šedo
authors.affiliation: Research Group Proteomics, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic.
authors.forename: Zbyněk
authors.initials: Z
authors.lastname: Zdráhal
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kašparovský
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Skládal
authors.affiliation: Department of Biochemistry, Faculty of Science, Masaryk University Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Lochman
keywords: cryptogein; dimerization; lipid transfer proteins; lysine residues; movement; resistance