The RING-Finger E3 Ubiquitin Ligase COP1 SUPPRESSOR1 Negatively Regulates COP1 Abundance in Maintaining COP1 Homeostasis in Dark-Grown Arabidopsis Seedlings
Artikel i vetenskaplig tidskrift, 2014

CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) functions as an E3 ubiquitin ligase in both plants and animals. In dark-grown Arabidopsis thaliana seedlings, COP1 targets photomorphogenesis-promoting factors for degradation to repress photomorphogenesis. Little is known, however, about how COP1 itself is regulated. Here, we identify COP1 SUPPRESSOR1 (CSU1), a RING-finger E3 ubiquitin ligase, as a regulator of COP1. Genetic evidence demonstrates that csu1 mutations suppress cop1-6 phenotypes completely in the dark. Furthermore, CSU1 colocalizes with COP1 in nuclear speckles and negatively regulates COP1 protein accumulation in darkness. CSU1 can ubiquitinate COP1 in vitro and is essential for COP1 ubiquitination in vivo. Therefore, we conclude that CSU1 plays a major role in maintaining COP1 homeostasis by targeting COP1 for ubiquitination and degradation in dark-grown seedlings.

GENE-EXPRESSION

LIGHT-DEPENDENT INTERACTION

Biochemistry & Molecular Biology

Cell Biology

CRYPTOCHROME

Plant Sciences

CONSTITUTIVELY

BLUE-LIGHT

B-BOX

PHOTOMORPHOGENIC1

1

TUMOR-SUPPRESSOR

UV-B

MEDIATED DEVELOPMENT

PROTEIN

PHOTOMORPHOGENIC REPRESSOR COP1

Författare

Dongqing Xu

Göteborgs universitet

Fang Lin

Jiang Yang

Göteborgs universitet

Xi Huang

Jigang Li

Junjie Ling

Chamari Hettiarachchi

Göteborgs universitet

Christian Tellgren-Roth

Magnus Holm

Göteborgs universitet

Xing Wang Deng

Plant Cell

1040-4651 (ISSN) 1532-298X (eISSN)

Vol. 26 1981-1991

Ämneskategorier

Biologiska vetenskaper

DOI

10.1105/tpc.114.124024