title: Coiled-coil domain-dependent homodimerization of intracellular barley immune receptors defines a minimal functional module for triggering cell death.
abstract: Plants and animals have evolved structurally related innate immune sensors, designated NLRs, to detect intracellular nonself molecules. NLRs are modular, consisting of N-terminal coiled-coil (CC) or TOLL/interleukin-1 receptor (TIR) domains, a central nucleotide-binding (NB) domain, and C-terminal leucine-rich repeats (LRRs). The polymorphic barley mildew A (MLA) locus encodes CC-containing allelic immune receptors recognizing effectors of the pathogenic powdery mildew fungus. We report the crystal structure of an MLA receptor's invariant CC domain, which reveals a rod-shaped homodimer. MLA receptors also self-associate in vivo, but self-association appears to be independent of effector-triggered receptor activation. MLA CC mutants that fail to self-interact impair in planta cell death activity triggered by the CC domain alone and by an autoactive full-length MLA receptor that mimics its ATP-bound state. Thus, CC domain-dependent dimerization of the immune sensor defines a minimal functional unit and implies a role for the dimeric CC module in downstream immune signaling.
authors.affiliation: Department of Plant-Microbe Interactions, Max-Planck Institut für Pflanzenzüchtungsforschung, Carl-von-Linne Weg 10, 50829 Cologne, Germany.
authors.forename: Takaki
authors.initials: T
authors.lastname: Maekawa
authors.affiliation: Beijing Normal University, Haidian District, 19 Xinjiekouwai Street, 100875 Beijing, China; National Institute of Biological Sciences, Number 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Bioinformatics and Structural Biochemistry, Institute of Biochemistry of the Romanian Academy, Splaiul Independentei 296, 060036, Bucharest, Romania.
authors.forename: Laurentiu N
authors.initials: LN
authors.lastname: Spiridon
authors.affiliation: Department of Plant-Microbe Interactions, Max-Planck Institut für Pflanzenzüchtungsforschung, Carl-von-Linne Weg 10, 50829 Cologne, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Töller
authors.affiliation: Department of 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
authors.affiliation: Department of Plant-Microbe Interactions, Max-Planck Institut für Pflanzenzüchtungsforschung, Carl-von-Linne Weg 10, 50829 Cologne, Germany.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Saijo
authors.affiliation: National Institute of Biological Sciences, Number 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China.
authors.forename: Peiyuan
authors.initials: P
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road, Chaoyang District, 100101 Beijing, China.
authors.forename: Qian-Hua
authors.initials: QH
authors.lastname: Shen
authors.affiliation: Department of Bioinformatics and Structural Biochemistry, Institute of Biochemistry of the Romanian Academy, Splaiul Independentei 296, 060036, Bucharest, Romania.
authors.forename: Marius A
authors.initials: MA
authors.lastname: Micluta
authors.affiliation: Department of Plant-Microbe Interactions, Max-Planck Institut für Pflanzenzüchtungsforschung, Carl-von-Linne Weg 10, 50829 Cologne, Germany.
authors.forename: Imre E
authors.initials: IE
authors.lastname: Somssich
authors.affiliation: Department of Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Frank L W
authors.initials: FLW
authors.lastname: Takken
authors.affiliation: Department of Bioinformatics and Structural Biochemistry, Institute of Biochemistry of the Romanian Academy, Splaiul Independentei 296, 060036, Bucharest, Romania.
authors.forename: Andrei-Jose
authors.initials: AJ
authors.lastname: Petrescu
authors.affiliation: National Institute of Biological Sciences, Number 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China; College of Biological Sciences, Tsinghua University, Haidian District, 100084 Beijing, China. Electronic address: chaijijie@nibs.ac.cn.
authors.forename: Jijie
authors.initials: J
authors.lastname: Chai
authors.affiliation: Department of Plant-Microbe Interactions, Max-Planck Institut für Pflanzenzüchtungsforschung, Carl-von-Linne Weg 10, 50829 Cologne, Germany. Electronic address: schlef@mpipz.mpg.de.
authors.forename: Paul
authors.initials: P
authors.lastname: Schulze-Lefert
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota; D016923:Cell Death; D002850:Chromatography, Gel; D018360:Crystallography, X-Ray; D017930:Genes, Reporter; D056426:Genetic Loci; D001467:Hordeum / Q000166:cytology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D057927:Hydrophobic and Hydrophilic Interactions; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000276:immunology; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D030821:Plants, Genetically Modified; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011971:Receptors, Immunologic / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D010940:Plant Proteins; D011971:Receptors, Immunologic; D011994:Recombinant Proteins