title: Protein-protein interactions as a proxy to monitor conformational changes and activation states of the tomato resistance protein I-2.
abstract: Plant resistance proteins (R) are involved in pathogen recognition and subsequent initiation of defence responses. Their activity is regulated by inter- and intramolecular interactions. In a yeast two-hybrid screen two clones (I2I-1 and I2I-2) specifically interacting with I-2, a Fusarium oxysporum f. sp. lycopersici resistance protein of the CC-NB-LRR family, were identified. Sequence analysis revealed that I2I-1 belongs to the Formin gene family (SlFormin) whereas I2I-2 has homology to translin-associated protein X (SlTrax). SlFormin required only the N-terminal CC I-2 domain for binding, whereas SlTrax required both I-2 CC and part of the NB-ARC domain. Tomato plants stably silenced for these interactors were not compromised in I-2-mediated disease resistance. When extended or mutated forms of I-2 were used as baits, distinct and often opposite, interaction patterns with the two interactors were observed. These interaction patterns correlated with the proposed activation state of I-2 implying that active and inactive R proteins adopt distinct conformations. It is concluded that the yeast two hybrid system can be used as a proxy to monitor these different conformational states.
authors.affiliation: Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Ewa
authors.initials: E
authors.lastname: Lukasik-Shreepaathy
authors.forename: Jack H
authors.initials: JH
authors.lastname: Vossen
authors.forename: Wladimir I L
authors.initials: WI
authors.lastname: Tameling
authors.forename: Marianne J
authors.initials: MJ
authors.lastname: de Vroomen
authors.forename: Ben J C
authors.initials: BJ
authors.lastname: Cornelissen
authors.forename: Frank L W
authors.initials: FL
authors.lastname: Takken
mesh_terms: D001681:Biological Assay; D060467:Disease Resistance / Q000276:immunology*; D005670:Fusarium / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant / Q000235:genetics; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D050505:Mutant Proteins / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D060066:Protein Interaction Maps; D017434:Protein Structure, Tertiary; D020798:Two-Hybrid System Techniques
chemical_list: D050505:Mutant Proteins; D010940:Plant Proteins