The COP9 signalosome interacts physically with SCF COI1 and modulates jasmonate responses.
The COP9 signalosome (CSN) is an evolutionarily conserved, nucleus-enriched multiprotein complex. CSN plays roles in photomorphogenesis, auxin response, and floral organ formation, possibly via the regulation of ubiquitin-proteasome-mediated protein degradation. COI1 encodes an F-box protein, which is a subunit of SCF(COI1) E3 ubiquitin ligase, and is required for jasmonate (JA) responses. Here, we demonstrate using coimmunoprecipitation and gel-filtration analyses that endogenous as well as epitope-tagged COI1 forms SCF(COI1) and associates directly with CSN in vivo. Like the coi1-1 mutant, CSN reduction-of-function plants exhibited a JA-insensitive root elongation phenotype and an absence of JA-induced-specific gene expression. Genome expression profile analyses indicated that JA-triggered genome expression is critically dependent on COI1 dosage. More importantly, most of the COI1-dependent JA-responsive genes also required CSN function, and CSN abundance was shown to be important for JA responses. Furthermore, we showed that both COI1 and CSN are essential for modulating the expression of genes in most cellular pathways responsive to JA. Thus, CSN and SCF(COI1) work together to control genome expression and promote JA responses.
Feng
Suhua
S
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104, USA.
Ma
Ligeng
L
Wang
Xiping
X
Xie
Daoxin
D
Dinesh-Kumar
S P
SP
Wei
Ning
N
Deng
Xing Wang
XW
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D000075686:COP9 Signalosome Complex; D003517:Cyclopentanes / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases
D029681:Arabidopsis Proteins; C112279:COI1 protein, Arabidopsis; C474638:CSN2 protein, Arabidopsis; C445070:CSN6B protein, Arabidopsis; D003517:Cyclopentanes; D054883:Oxylipins; D011993:Recombinant Fusion Proteins; C011006:jasmonic acid; D044843:SKP Cullin F-Box Protein Ligases; D000075686:COP9 Signalosome Complex; D010453:Peptide Synthases