title: Arabidopsis resistance protein SNC1 activates immune responses through association with a transcriptional corepressor.
abstract: In both plants and animals, nucleotide-binding (NB) domain and leucine-rich repeat (LRR)-containing proteins (NLR) function as sensors of pathogen-derived molecules and trigger immune responses. Although NLR resistance (R) proteins were first reported as plant immune receptors more than 15 years ago, how these proteins activate downstream defense responses is still unclear. Here we report that the Toll-like/interleukin-1 receptor (TIR)-NB-LRR R protein, suppressor of npr1-1, constitutive 1 (SNC1) functions through its associated protein, Topless-related 1 (TPR1). Knocking out TPR1 and its close homologs compromises immunity mediated by SNC1 and several other TIR-NB-LRR-type R proteins, whereas overexpression of TPR1 constitutively activates SNC1-mediated immune responses. TPR1 functions as a transcriptional corepressor and associates with histone deacetylase 19 in vivo. Among the target genes of TPR1 are Defense no Death 1 (DND1) and Defense no Death 2 (DND2), two known negative regulators of immunity that are repressed during pathogen infection, suggesting that TPR1 activates R protein-mediated immune responses through repression of negative regulators.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, China Agricultural University, Beijing 100094, China.
authors.forename: Zhaohai
authors.initials: Z
authors.lastname: Zhu
authors.forename: Fang
authors.initials: F
authors.lastname: Xu
authors.forename: Yaxi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yu Ti
authors.initials: YT
authors.lastname: Cheng
authors.forename: Marcel
authors.initials: M
authors.lastname: Wiermer
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Yuelin
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000276:immunology* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000276:immunology*; D018506:Gene Expression Regulation, Plant; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D030821:Plants, Genetically Modified; D011485:Protein Binding; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; C482739:SNC1 protein, Arabidopsis; C551919:topless-related 1 protein, Arabidopsis; D006655:Histone Deacetylases