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Auxin sensitivities of all Arabidopsis Aux/IAAs for degradation in the presence of every TIR1/AFB.
Plant Cell Physiol. 2014 Aug; 55(8):1450-9.PC

Abstract

Auxin plays a key role in regulation of almost all processes of plant growth and development. Different physiological processes are regulated by different ranges of auxin concentrations; however, the underlying mechanisms creating these differences are largely unknown. The first step of auxin signaling is auxin-dependent interaction of an auxin receptor with transcriptional co-repressors (Aux/IAA), which leads to Aux/IAA degradation. Arabidopsis has six homologous auxin receptors (TIR1 and five AFBs), 29 Aux/IAA proteins and two types of active auxins, IAA and phenylacetic acid (PAA). Therefore, a large number of possible combinations between these three factors may contribute to the creation of complex auxin responses. Using a yeast heterologous reconstitution system, we investigated auxin-dependent degradation of all Arabidopsis Aux/IAAs in combination with every TIR or AFB receptor component. We found that TIR1 and AFB2 were effective in mediating Aux/IAA degradation. We confirmed that the Aux/IAA domain II, which binds TIR1, is essential for degradation. IAA and other natural auxins, 4-chloroindole-3-acetic acid (4-Cl-IAA) and PAA, induced Aux/IAA degradation; and IAA and 4-Cl-IAA had higher activity than PAA. Effective auxin concentrations for Aux/IAA degradation depended on both Aux/IAAs and TIR1 or AFB2 receptors, which is consistent with the Aux/IAA-TIR1/AFB co-receptor concept.

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Publisher Full Text (DOI)

Authors+Show Affiliations

Shimizu-Mitao Y
Department of Biological Science, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043 Japan.
Kakimoto T
Department of Biological Science, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043 Japan kakimoto@bio.sci.osaka-u.ac.jp.

MeSH

Amino Acid SequenceArabidopsisArabidopsis ProteinsDNA-Binding ProteinsF-Box ProteinsGene Expression Regulation, PlantGenes, ReporterIndoleacetic AcidsMolecular Sequence DataNuclear ProteinsPlant Growth RegulatorsPlants, Genetically ModifiedProteolysisReceptors, Cell SurfaceSequence AlignmentSignal TransductionTwo-Hybrid System Techniques

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

24880779

Citation

Shimizu-Mitao, Yasushi, and Tatsuo Kakimoto. "Auxin Sensitivities of All Arabidopsis Aux/IAAs for Degradation in the Presence of Every TIR1/AFB." Plant & Cell Physiology, vol. 55, no. 8, 2014, pp. 1450-9.
Shimizu-Mitao Y, Kakimoto T. Auxin sensitivities of all Arabidopsis Aux/IAAs for degradation in the presence of every TIR1/AFB. Plant Cell Physiol. 2014;55(8):1450-9.
Shimizu-Mitao, Y., & Kakimoto, T. (2014). Auxin sensitivities of all Arabidopsis Aux/IAAs for degradation in the presence of every TIR1/AFB. Plant & Cell Physiology, 55(8), 1450-9. https://doi.org/10.1093/pcp/pcu077
Shimizu-Mitao Y, Kakimoto T. Auxin Sensitivities of All Arabidopsis Aux/IAAs for Degradation in the Presence of Every TIR1/AFB. Plant Cell Physiol. 2014;55(8):1450-9. PubMed PMID: 24880779.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Auxin sensitivities of all Arabidopsis Aux/IAAs for degradation in the presence of every TIR1/AFB. AU - Shimizu-Mitao,Yasushi, AU - Kakimoto,Tatsuo, Y1 - 2014/05/31/ PY - 2014/6/2/entrez PY - 2014/6/2/pubmed PY - 2015/4/22/medline KW - AFB KW - Arabidopsis thaliana KW - Aux/IAA KW - Auxin KW - Sensitivity KW - TIR1 SP - 1450 EP - 9 JF - Plant & cell physiology JO - Plant Cell Physiol VL - 55 IS - 8 N2 - Auxin plays a key role in regulation of almost all processes of plant growth and development. Different physiological processes are regulated by different ranges of auxin concentrations; however, the underlying mechanisms creating these differences are largely unknown. The first step of auxin signaling is auxin-dependent interaction of an auxin receptor with transcriptional co-repressors (Aux/IAA), which leads to Aux/IAA degradation. Arabidopsis has six homologous auxin receptors (TIR1 and five AFBs), 29 Aux/IAA proteins and two types of active auxins, IAA and phenylacetic acid (PAA). Therefore, a large number of possible combinations between these three factors may contribute to the creation of complex auxin responses. Using a yeast heterologous reconstitution system, we investigated auxin-dependent degradation of all Arabidopsis Aux/IAAs in combination with every TIR or AFB receptor component. We found that TIR1 and AFB2 were effective in mediating Aux/IAA degradation. We confirmed that the Aux/IAA domain II, which binds TIR1, is essential for degradation. IAA and other natural auxins, 4-chloroindole-3-acetic acid (4-Cl-IAA) and PAA, induced Aux/IAA degradation; and IAA and 4-Cl-IAA had higher activity than PAA. Effective auxin concentrations for Aux/IAA degradation depended on both Aux/IAAs and TIR1 or AFB2 receptors, which is consistent with the Aux/IAA-TIR1/AFB co-receptor concept. SN - 1471-9053 UR - https://www.unboundmedicine.com/medline/citation/24880779/Auxin_sensitivities_of_all_Arabidopsis_Aux/IAAs_for_degradation_in_the_presence_of_every_TIR1/AFB_ DB - PRIME DP - Unbound Medicine ER -