Arabidopsis CAND1, an unmodified CUL1-interacting protein, is involved in multiple developmental pathways controlled by ubiquitin/proteasome-mediated protein Degradation.
Ubiquitin/proteasome-mediated protein degradation controls various developmental pathways in eukaryotes. Cullin-containing complexes are both versatile and abundant groups of RING family ubiquitin E3 ligases, whose activities are subject to control by RUB/Nedd8 (for related to ubiquitin/neural precursor cell-expressed developmentally downregulated 8) modification of their cullin subunits. Here, we report the identification of an Arabidopsis thaliana counterpart of human CAND1 (cullin-associated and neddylation-dissociated) and demonstrate that it can preferentially interact with unmodified CUL1. The Arabidopsis cand1-1 null mutant displays distinct phenotypes, including late flowering, aerial rosettes, floral organ defects, low fertility, dwarfism, loss of apical dominance, and altered responses to multiple plant hormones. Molecular analyses show that many of these defects are because of compromised activity of CUL1-containing ubiquitin E3 ligases, indicating that CAND1 is required for their optimal activity. Furthermore, the cand1-1 mutant displays a partial constitutive photomorphogenic phenotype and has defects in HY5 degradation in the absence of light, a process mediated by a different RING family E3, COP1. Thus, our data provides genetic support for a critical role of CAND1 in regulating various ubiquitin E3 ligases and their targeted cellular and developmental pathways.
Feng
Suhua
S
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Conecticut 06520-8104, USA.
Shen
Yunping
Y
Sullivan
James A
JA
Rubio
Vicente
V
Xiong
Yue
Y
Sun
Tai-ping
TP
Deng
Xing Wang
XW
D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D044842:Cullin Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D035264:Flowers / Q000254:growth & development; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D030821:Plants, Genetically Modified; D025801:Ubiquitin / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D029681:Arabidopsis Proteins; C488785:CAND1 protein, Arabidopsis; D018797:Cell Cycle Proteins; C100318:Cullin 1; D044842:Cullin Proteins; D004269:DNA, Bacterial; C036483:T-DNA; D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases