title: Arabidopsis stress associated protein 9 mediates biotic and abiotic stress responsive ABA signaling via the proteasome pathway.
abstract: Arabidopsis thaliana Stress Associated Protein 9 (AtSAP9) is a member of the A20/AN1 zinc finger protein family known to play important roles in plant stress responses and in the mammalian immune response. Although SAPs of several plant species were shown to be involved in abiotic stress responses, the underlying molecular mechanisms are largely unknown, and little is known about the involvement of SAPs in plant disease responses. Expression of SAP9 in Arabidopsis is up-regulated in response to dehydration, cold, salinity and abscisic acid (ABA), as well as pathogen infection. Constitutive expression of AtSAP9 in Arabidopsis leads to increased sensitivity to ABA and osmotic stress during germination and post-germinative development. Plants that overexpress AtSAP9 also showed increased susceptibility to infection by non-host pathogen Pseudomonas syringae pv. phaseolicola, indicating a potential role of AtSAP9 in disease resistance. AtSAP9 was found to interact with RADIATION SENSITIVE23d (Rad23d), a shuttle factor for the transport of ubiquitinated substrates to the proteasome, and it is co-localized with Rad23d in the nucleus. Thus, AtSAP9 may promote the protein degradation process by mediating the interaction of ubiquitinated targets with Rad23d. Taken together, these results indicate that AtSAP9 regulates abiotic and biotic stress responses, possibly via the ubiquitination/proteasome pathway.
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.|Institute of Agricultural Bioscience, Oklahoma State University, Ardmore, OK, 73401, USA.
authors.forename: Miyoung
authors.initials: M
authors.lastname: Kang
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.|Current address: Gulf Coast Research and Education Center, Institute of Food and Agricultural Science, University of Florida, Balm, FL, 33598, USA.
authors.forename: Seonghee
authors.initials: S
authors.lastname: Lee
authors.affiliation: Institute of Agricultural Bioscience, Oklahoma State University, Ardmore, OK, 73401, USA.|Department of Agricultural Botany, Cairo University, Giza, 12613, Egypt.
authors.forename: Haggag
authors.initials: H
authors.lastname: Abdelmageed
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.|Institute of Agricultural Bioscience, Oklahoma State University, Ardmore, OK, 73401, USA.|Weitkampweg 81, 49084, Osnabrück, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Reichert
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Hee-Kyung
authors.initials: HK
authors.lastname: Lee
authors.affiliation: Institute of Agricultural Bioscience, Oklahoma State University, Ardmore, OK, 73401, USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Fokar
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK, 73401, USA.
authors.forename: Kirankumar S
authors.initials: KS
authors.lastname: Mysore
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.|Institute of Agricultural Bioscience, Oklahoma State University, Ardmore, OK, 73401, USA.|Weitkampweg 81, 49084, Osnabrück, Germany.
authors.forename: Randy D
authors.identifier: http://orcid.org/0000-0003-2111-2629
authors.initials: RD
authors.lastname: Allen
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination / Q000235:genetics; D054884:Host-Pathogen Interactions / Q000235:genetics; D009997:Osmotic Pressure; D057865:Plant Immunity / Q000235:genetics; D030821:Plants, Genetically Modified; D025821:Polyubiquitin / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D044224:Pseudomonas syringae / Q000502:physiology; D015398:Signal Transduction; D013312:Stress, Physiological / Q000235:genetics; D013997:Time Factors; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D020033:Protein Isoforms; D025821:Polyubiquitin; D000040:Abscisic Acid; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex
keywords: AtSAP9; Rad23d; UPS