Arabidopsis COP10 forms a complex with DDB1 and DET1 in vivo and enhances the activity of ubiquitin conjugating enzymes.
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.
Yanagawa
Yuki
Y
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104, USA.
Sullivan
James A
JA
Komatsu
Setsuko
S
Gusmaroli
Giuliana
G
Suzuki
Genki
G
Yin
Jianning
J
Ishibashi
Toyotaka
T
Saijo
Yusuke
Y
Rubio
Vicente
V
Kimura
Seisuke
S
Wang
Jian
J
Deng
Xing Wang
XW
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
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