title: The ubiquitin ligase SEVEN IN ABSENTIA (SINA) ubiquitinates a defense-related NAC transcription factor and is involved in defense signaling.
abstract: We recently identified a defense-related tomato (Solanum lycopersicum) NAC (NAM, ATAF1,2, CUC2) transcription factor, NAC1, that is subjected to ubiquitin-proteasome system-dependent degradation in plant cells. In this study, we identified a tomato ubiquitin ligase (termed SEVEN IN ABSENTIA3; SINA3) that ubiquitinates NAC1, promoting its degradation. We conducted coimmunoprecipitation and bimolecular fluorescence complementation to determine that SINA3 specifically interacts with the NAC1 transcription factor in the nucleus. Moreover, we found that SINA3 ubiquitinates NAC1 in vitro and promotes NAC1 degradation via polyubiquitination in vivo, indicating that SINA3 is a ubiquitin ligase that ubiquitinates NAC1, promoting its degradation. Our real-time PCR analysis indicated that, in contrast to our previous finding that NAC1 mRNA abundance increases upon Pseudomonas infection, the SINA3 mRNA abundance decreases in response to Pseudomonas infection. Moreover, using Agrobacterium-mediated transient expression, we found that overexpression of SINA3 interferes with the hypersensitive response cell death triggered by multiple plant resistance proteins. These results suggest that SINA3 ubiquitinates a defense-related NAC transcription factor for degradation and plays a negative role in defense signaling.
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Miao
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Ministry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610064, China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Niu
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kud
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339, USA.
authors.forename: Xinran
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 83844-2339, USA.
authors.forename: Julian
authors.initials: J
authors.lastname: Avila
authors.affiliation: Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 83844-2339, USA.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Devarenne
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Kuhl
authors.affiliation: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, China.|Ministry of Education Key Laboratory for Bio-resource and Eco-environment, College of Life Science, State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, Sichuan, 610064, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339, USA.
authors.forename: Fangming
authors.initials: F
authors.lastname: Xiao
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018551:Solanum lycopersicum / Q000382:microbiology / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D059748:Proteolysis; D011549:Pseudomonas / Q000472:pathogenicity; D015398:Signal Transduction; D014026:Nicotiana / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases
keywords: NAC (NAM, ATAF1,2, CUC2) transcription factor; SEVEN IN ABSENTIA (SINA) ubiquitin ligase; plant defense response; tomato (Solanum lycopersicum); ubiquitin-proteasome system (UPS)-mediated degradation