ASG2 is a farnesylated DWD protein that acts as ABA negative regulator in Arabidopsis

• Published in: Plant, cell and environment Vol. 39; no. 1; pp. 185 - 198
• Main Authors: Dutilleul, Christelle, Ribeiro, Iliana, Blanc, Nathalie, Nezames, Cynthia D, Deng, Xing Wang, Zglobicki, Piotr, Palacio Barrera, Ana María, Atehortùa, Lucia, Courtois, Martine, Labas, Valérie, Giglioli‐Guivarc'h, Nathalie, Ducos, Eric
• Format: Journal Article
• Language: English
• Published: United States Blackwell Scientific Publications 01-01-2016; Wiley Subscription Services, Inc; Wiley
• Subjects: ABA signalling; abscisic acid; Abscisic Acid - metabolism; alkynes; Amino Acid Sequence; Arabidopsis; Arabidopsis - cytology; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; biotin; cell culture; chemistry; chromatography; DDB1 CUL4 E3 ubiquitin ligase; DNA damage; DNA-binding proteins; Gene Expression Regulation, Plant; genes; Genes, Reporter; geranylgeranyl diphosphate synthase; Germination; guanosinetriphosphatase; Life Sciences; mammals; mass spectrometry; Molecular Sequence Data; mutants; Mutation; Other; Phenotype; Plant Growth Regulators - metabolism; Plant Roots - cytology; Plant Roots - drug effects; Plant Roots - genetics; Plant Roots - physiology; Plants, Genetically Modified; protein farnesylation; Protein Prenylation; Protein Transport; protoplasts; Recombinant Fusion Proteins; root growth; salt stress; seed germination; Sequence Alignment; Sodium Chloride - pharmacology; Stress, Physiological; tagging‐via‐substrate; Transducin - genetics; Transducin - metabolism; tagging-via-substrate; protein farnesylation; ABA signalling; DDB1 CUL4 E3 ubiquitin ligase; spectrométrie de masse; plante; ddb1 cul4 e3 ubiquitin ligase; mass spectrum analysis; sds page; extraction de protéines; dwd protein; aba signaling; arabidopsis
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.12605

The tagging‐via‐substrate approach designed for the capture of mammal prenylated proteins was adapted to Arabidopsis cell culture. In this way, proteins are in vivo tagged with an azide‐modified farnesyl moiety and captured thanks to biotin alkyne Click‐iT® chemistry with further streptavidin‐affinity chromatography. Mass spectrometry analyses identified four small GTPases and ASG2 (ALTERED SEED GERMINATION 2), a protein previously associated to the seed germination gene network. ASG2 is a conserved protein in plants and displays a unique feature that associates WD40 domains and tetratricopeptide repeats. Additionally, we show that ASG2 has a C‐terminal CaaX‐box that is farnesylated in vitro. Protoplast transfections using CaaX prenyltransferase mutants show that farnesylation provokes ASG2 nucleus exclusion. Moreover, ASG2 interacts with DDB1 (DAMAGE DNA BINDING protein 1), and the subcellular localization of this complex depends on ASG2 farnesylation status. Finally, germination and root elongation experiments reveal that asg2 and the farnesyltransferase mutant era1 (ENHANCED RESPONSE TO ABSCISIC ACID (ABA) 1) behave in similar manners when exposed to ABA or salt stress. To our knowledge, ASG2 is the first farnesylated DWD (DDB1 binding WD40) protein related to ABA response in Arabidopsis that may be linked to era1 phenotypes.