title: Arabidopsis COP10 forms a complex with DDB1 and DET1 in vivo and enhances the activity of ubiquitin conjugating enzymes.
abstract: COP10 is a ubiquitin-conjugating enzyme variant (UEV), which is thought to act together with COP1, DET1, and the COP9 signalosome (CSN) in Arabidopsis to repress photomorphogenesis. Here, we demonstrate that COP10 interacts with ubiquitin-conjugating enzymes (E2s) in vivo, and can enhance their activity in vitro, an activity distinct from previous characterized UEVs such as MMS2 and UEV1. Furthermore, we show that COP10 forms a complex with UV-damaged DNA-binding protein 1a (DDB1a) and de-etiolated 1 (DET1), and physically interacts with COP1 and the CSN. Purified CDD (COP10, DDB1, DET1) complex also shows enhancement of E2 activity (UEA) similar to that observed with COP10 itself. Our data suggests that COP10, along with COP1 and the CSN, promotes the degradation of positive regulators of photomorphogenesis, such as the transcription factor HY5, via the ubiquitin/26S proteasome system. Thus, the CDD complex may act as a ubiquitylation-promoting factor to regulate photomorphogenesis.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104, USA.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: James A
authors.initials: JA
authors.lastname: Sullivan
authors.forename: Setsuko
authors.initials: S
authors.lastname: Komatsu
authors.forename: Giuliana
authors.initials: G
authors.lastname: Gusmaroli
authors.forename: Genki
authors.initials: G
authors.lastname: Suzuki
authors.forename: Jianning
authors.initials: J
authors.lastname: Yin
authors.forename: Toyotaka
authors.initials: T
authors.lastname: Ishibashi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Saijo
authors.forename: Vicente
authors.initials: V
authors.lastname: Rubio
authors.forename: Seisuke
authors.initials: S
authors.lastname: Kimura
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Xing Wang
authors.initials: XW
authors.lastname: Deng
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D000075686:COP9 Signalosome Complex; D002850:Chromatography, Gel; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins; D008027:Light; D008954:Models, Biological; D009024:Morphogenesis; D009687:Nuclear Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011233:Precipitin Tests; D011506:Proteins / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases
chemical_list: D029681:Arabidopsis Proteins; C086322:CSN1 protein, Arabidopsis; C088435:DET1 protein, Arabidopsis; D017931:DNA Primers; D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D011506:Proteins; D025801:Ubiquitin; C450820:COP10 protein, Arabidopsis; D044763:Ubiquitin-Conjugating Enzymes; C471983:AT2G32950 protein, Arabidopsis; D044767:Ubiquitin-Protein Ligases; D000075686:COP9 Signalosome Complex