The COP9 signalosome interacts with SCF UFO and participates in Arabidopsis flower development.
The COP9 signalosome (CSN) is involved in multiple developmental processes. It interacts with SCF ubiquitin ligases and deconjugates Nedd8/Rub1 from cullins (deneddylation). CSN is highly expressed in Arabidopsis floral tissues. To investigate the role of CSN in flower development, we examined the expression pattern of CSN in developing flowers. We report here that two csn1 partially deficient Arabidopsis strains exhibit aberrant development of floral organs, decline of APETALA3 (AP3) expression, and low fertility in addition to defects in shoot and inflorescence meristems. We show that UNUSUAL FLORAL ORGANS (UFO) forms a SCF(UFO) complex, which is associated with CSN in vivo. Genetic interaction analysis indicates that CSN is necessary for the gain-of-function activity of the F-box protein UFO in AP3 activation and in floral organ transformation. Compared with the previously reported csn5 antisense and csn1 null mutants, partial deficiency of CSN1 causes a reduction in the level of CUL1 in the mutant flowers without an obvious defect in CUL1 deneddylation. We conclude that CSN is an essential regulator of Arabidopsis flower development and suggest that CSN regulates Arabidopsis flower development in part by modulating SCF(UFO)-mediated AP3 activation.
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA.
Xiping
X
Wang
Suhua
S
Feng
Naomi
N
Nakayama
W L
WL
Crosby
Vivian
V
Irish
Xing Wang
XW
Deng
Ning
N
Wei
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D000075686:COP9 Signalosome Complex; D035264:Flowers / Q000235:genetics / Q000254:growth & development*; D019204:GTP-Binding Proteins; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D047908:Intracellular Signaling Peptides and Proteins; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D009154:Mutation; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D030821:Plants, Genetically Modified; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins; D044843:SKP Cullin F-Box Protein Ligases
C120363:ASK1 protein, Arabidopsis; D029681:Arabidopsis Proteins; C086322:CSN1 protein, Arabidopsis; C474638:CSN2 protein, Arabidopsis; C445070:CSN6B protein, Arabidopsis; C103315:GPS1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D012097:Repressor Proteins; D044843:SKP Cullin F-Box Protein Ligases; D000075686:COP9 Signalosome Complex; D019204:GTP-Binding Proteins; D010453:Peptide Synthases