title: MATH/BTB CRL3 receptors target the homeodomain-leucine zipper ATHB6 to modulate abscisic acid signaling.
abstract: Being sessile organisms, plants need rapid and finely tuned signaling pathways to adapt their growth and survival over their immediate and often adverse environment. Abscisic acid (ABA) is a plant hormone crucial for both biotic and abiotic stress responses. In this study, we highlight a function of six Arabidopsis MATH-BTB proteins in ABA signaling. MATH-BTB proteins act as substrate-binding adaptors for the Cullin3-based ubiquitin E3 ligase. Our genetic and biochemical experiments demonstrate that the MATH-BTB proteins directly interact with and target for proteasomal degradation the class I homeobox-leucine zipper (HD-ZIP) transcription factor ATHB6, which was previously identified as a negative regulator of ABA responses. Reducing CUL3(BPM) function leads to higher ATHB6 protein accumulation, reducing plant growth and fertility, and affects stomatal behavior and responses to ABA. We further demonstrate that ABA negatively regulates ATHB6 protein turnover, a situation reminiscent to ABI5, another transcription factor involved in ABA signaling.
authors.affiliation: Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Unité Propre de Recherche 2357, Conventionné avec l'Université de Strasbourg, 67084 Strasbourg, France.
authors.forename: E
authors.initials: E
authors.lastname: Lechner
authors.forename: N
authors.initials: N
authors.lastname: Leonhardt
authors.forename: H
authors.initials: H
authors.lastname: Eisler
authors.forename: Y
authors.initials: Y
authors.lastname: Parmentier
authors.forename: M
authors.initials: M
authors.lastname: Alioua
authors.forename: H
authors.initials: H
authors.lastname: Jacquet
authors.forename: J
authors.initials: J
authors.lastname: Leung
authors.forename: P
authors.initials: P
authors.lastname: Genschik
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D044842:Cullin Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D016350:Leucine Zippers; D010802:Phylogeny; D030821:Plants, Genetically Modified; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D029681:Arabidopsis Proteins; C122165:AtHB6 protein, Arabidopsis; D044842:Cullin Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; D000040:Abscisic Acid; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex