title: Identification of Arabidopsis MYB56 as a novel substrate for CRL3(BPM) E3 ligases.
abstract: Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in living cells. A key regulatory system for protein stability is given by the ubiquitin proteasome pathway, which uses E3 ligases to mark specific proteins for degradation. In this work, MYB56 is identified as a novel target of a CULLIN3 (CUL3)-based E3 ligase. Its stability depends on the presence of MATH-BTB/POZ (BPM) proteins, which function as substrate adaptors to the E3 ligase. Genetic studies have indicated that MYB56 is a negative regulator of flowering, while BPMs positively affect this developmental program. The interaction between BPMs and MYB56 occurs at the promoter of FLOWERING LOCUS T (FT), a key regulator in initiating flowering in Arabidopsis, and results in instability of MYB56. Overall the work establishes MYB transcription factors as substrates of BPM proteins, and provides novel information on components that participate in controlling flowering time in plants.
authors.affiliation: School of Biological Sciences, Washington State University, Abelson 435, Pullman, WA 99164-4236, USA.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Chen
authors.affiliation: School of Biological Sciences, Washington State University, Abelson 435, Pullman, WA 99164-4236, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Bernhardt
authors.affiliation: School of Biological Sciences, Washington State University, Abelson 435, Pullman, WA 99164-4236, USA.
authors.forename: JooHyun
authors.initials: J
authors.lastname: Lee
authors.affiliation: School of Biological Sciences, Washington State University, Abelson 435, Pullman, WA 99164-4236, USA. Electronic address: hellmann@wsu.edu.
authors.forename: Hanjo
authors.initials: H
authors.lastname: Hellmann
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C418905:FT protein, Arabidopsis; C000588964:MYB56 protein, Arabidopsis; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases
keywords: BPM; CUL3; E3 ligase; MYB; flowering; transcription factor