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Light and the E3 ubiquitin ligase COP1/SPA control the protein stability of the MYB transcription factors PAP1 and PAP2 involved in anthocyanin accumulation in Arabidopsis
- Source :
- The Plant journal : for cell and molecular biology. 74(4)
- Publication Year :
- 2012
-
Abstract
- Summary Anthocyanins are natural pigments that accumulate only in light-grown and not in dark-grown Arabidopsis plants. Repression of anthocyanin accumulation in darkness requires the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA-105 (COP1/SPA) ubiquitin ligase, as cop1 and spa mutants produce anthocyanins also in the dark. Here, we show that COP1 and SPA proteins interact with the myeloblastosis (MYB) transcription factors PRODUCTION OF ANTHOCYANIN PIGMENT1 (PAP)1 and PAP2, two members of a small protein family that is required for anthocyanin accumulation and for the expression of structural genes in the anthocyanin biosynthesis pathway. The increased anthocyanin levels in cop1 mutants requires the PAP1 gene family, indicating that COP1 functions upstream of the PAP1 gene family. PAP1 and PAP2 proteins are degraded in the dark and this degradation is dependent on the proteasome and on COP1. Hence, the light requirement for anthocyanin biosynthesis results, at least in part, from the light-mediated stabilization of PAP1 and PAP2. Consistent with this conclusion, moderate overexpression of PAP1 leads to an increase in anthocyanin levels only in the light and not in darkness. Here we show that SPA genes are also required for reducing PAP1 and PAP2 transcript levels in dark-grown seedlings. Taken together, these results indicate that the COP1/SPA complex affects PAP1 and PAP2 both transcriptionally and post-translationally. Thus, our findings have identified mechanisms via which the COP1/SPA complex controls anthocyanin levels in Arabidopsis that may be useful for applications in biotechnology directed towards increasing anthocyanin content in plants.
- Subjects :
- Light
Recombinant Fusion Proteins
Ubiquitin-Protein Ligases
Arabidopsis
Down-Regulation
Gene Expression
Pancreatitis-Associated Proteins
Plant Science
Protein degradation
Anthocyanins
Gene Expression Regulation, Plant
Two-Hybrid System Techniques
Genetics
Gene family
Arabidopsis thaliana
MYB
biology
Arabidopsis Proteins
Protein Stability
fungi
Structural gene
food and beverages
Cell Biology
Darkness
biology.organism_classification
Plants, Genetically Modified
Ubiquitin ligase
Protein Structure, Tertiary
carbohydrates (lipids)
Biochemistry
Seedlings
Multiprotein Complexes
Mutation
Proteolysis
biology.protein
Photomorphogenesis
Transcription Factors
Subjects
Details
- ISSN :
- 1365313X
- Volume :
- 74
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- The Plant journal : for cell and molecular biology
- Accession number :
- edsair.doi.dedup.....5416eaa9fa89246c14b30217603e54fa