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Liu Y, Wang Q, Abbas F, Zhou Y, He J, Fan Y, Yu R. Light Regulation of LoCOP1 and Its Role in Floral Scent Biosynthesis in Lilium 'Siberia'. PLANTS (BASEL, SWITZERLAND) 2023; 12:2004. [PMID: 37653921 PMCID: PMC10223427 DOI: 10.3390/plants12102004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 09/02/2023]
Abstract
Light is an important environmental signal that governs plant growth, development, and metabolism. Constitutive photomorphogenic 1 (COP1) is a light signaling component that plays a vital role in plant light responses. We isolated the COP1 gene (LoCOP1) from the petals of Lilium 'Siberia' and investigated its function. The LoCOP1 protein was found to be the most similar to Apostasia shenzhenica COP1. LoCOP1 was found to be an important factor located in the nucleus and played a negative regulatory role in floral scent production and emission using the virus-induced gene silencing (VIGS) approach. The yeast two-hybrid, β-galactosidase, and bimolecular fluorescence complementation (BiFC) assays revealed that LoCOP1 interacts with LoMYB1 and LoMYB3. Furthermore, light modified both the subcellular distribution of LoCOP1 and its interactions with LoMYB1 and MYB3 in onion cells. The findings highlighted an important regulatory mechanism in the light signaling system that governs scent emission in Lilium 'Siberia' by the ubiquitination and degradation of transcription factors via the proteasome pathway.
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Affiliation(s)
- Yang Liu
- The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Q.W.); (F.A.); (Y.Z.); (J.H.)
| | - Qin Wang
- The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Q.W.); (F.A.); (Y.Z.); (J.H.)
| | - Farhat Abbas
- The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Q.W.); (F.A.); (Y.Z.); (J.H.)
| | - Yiwei Zhou
- The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Q.W.); (F.A.); (Y.Z.); (J.H.)
| | - Jingjuan He
- The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Q.W.); (F.A.); (Y.Z.); (J.H.)
| | - Yanping Fan
- The Research Center for Ornamental Plants, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China; (Y.L.); (Q.W.); (F.A.); (Y.Z.); (J.H.)
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, South China Agricultural University, Guangzhou 510642, China
| | - Rangcai Yu
- College of Life Sciences, South China Agricultural University, Guangzhou 510642, China
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Kreiss M, Haas FB, Hansen M, Rensing SA, Hoecker U. Co-action of COP1, SPA and cryptochrome in light signal transduction and photomorphogenesis of the moss Physcomitrium patens. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:159-175. [PMID: 36710658 DOI: 10.1111/tpj.16128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The Arabidopsis COP1/SPA ubiquitin ligase suppresses photomorphogenesis in darkness. In the light, photoreceptors inactivate COP1/SPA to allow a light response. While SPA genes are specific to the green lineage, COP1 also exists in humans. This raises the question of when in evolution plant COP1 acquired the need for SPA accessory proteins. We addressed this question by generating Physcomitrium Ppcop1 mutants and comparing their visible and molecular phenotypes with those of Physcomitrium Ppspa mutants. The phenotype of Ppcop1 nonuple mutants resembles that of Ppspa mutants. Most importantly, both mutants produce green chloroplasts in complete darkness. They also exhibit dwarfed gametophores, disturbed branching of protonemata and absent gravitropism. RNA-sequencing analysis indicates that both mutants undergo weak constitutive light signaling in darkness. PpCOP1 and PpSPA proteins form a complex and they interact via their WD repeat domains with the VP motif of the cryptochrome CCE domain in a blue light-dependent manner. This resembles the interaction of Arabidopsis SPA proteins with Arabidopsis CRY1, and is different from that with Arabidopsis CRY2. Taken together, the data indicate that PpCOP1 and PpSPA act together to regulate growth and development of Physcomitrium. However, in contrast to their Arabidopsis orthologs, PpCOP1 and PpSPA proteins execute only partial suppression of light signaling in darkness. Hence, additional repressors may exist that contribute to the repression of a light response in dark-exposed Physcomitrium.
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Affiliation(s)
- Melanie Kreiss
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674, Cologne, Germany
| | - Fabian B Haas
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Maike Hansen
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674, Cologne, Germany
| | - Stefan A Rensing
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Ute Hoecker
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674, Cologne, Germany
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Liu Q, Li Z, Zhang M, Dong S, Yang P, Zhang J, Loades E. Systematic analysis of photo/sko-regulated germination and post-germination development of shallow photodormant seeds in Nicotiana tabacum L. FRONTIERS IN PLANT SCIENCE 2023; 13:1042981. [PMID: 36714753 PMCID: PMC9875545 DOI: 10.3389/fpls.2022.1042981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 11/22/2022] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Light is a major environmental factor in regulating germination and post-germination development of shallow photo-dormant seeds in Nicotiana tabacum L. (tobacco). However, its molecular mechanism remains largely unclear. METHODS AND RESULTS In this study, we compared the phenotypes of the seeds germinated under light and dark, and systematically investigated their regulatory networks by integrating transcriptomic and proteomic data. Under light, the germination increased ~25%, the length of the hypocotyl shortened ~3 cm, and the apical hook disappeared. 9, 161, 342 differentially expressed genes (DEGs) and 128, 185, 81 differentially expressed proteins (DEPs) were regulated by light in the development stage of seed imbibition, radicle protrusion and cotyledon expansion respectively. 0, 19 and 1 co-up-regulated and 1, 30 and 64 co-down-regulated DEGs (DEP) were observed in the three stages, respectively. Of them, 2S albumin large chain, was down-regulated by light in imbibed seed. Oleosin 18.5 kDa (OLEO1) and Glyceraldehyde-3-phosphate dehydrogenase (GAPA1), Oxygen-evolving enhancer protein 1-1 and anchloroplastic (PSBO1), hub genes (proteins) in protein-protein interaction network (PPI), were downregulated and up-regulated in germinated seeds by light, respectively. OLEO1, a hub gene (proteins), was down-regulated by light in post-germination seedling. CONCLUSION These results systematically revealed the molecular networks regulated by light during germination and post-germination development of shallow photo-dormant tobacco seeds.
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Affiliation(s)
- Qiyuan Liu
- College of Agriculture, University of Guizhou, Guiyang, Guizhou, China
| | - Zhenhua Li
- College of Agriculture, University of Guizhou, Guiyang, Guizhou, China
| | - Min Zhang
- College of Agriculture, University of Guizhou, Guiyang, Guizhou, China
| | - Shuai Dong
- College of Agriculture, University of Guizhou, Guiyang, Guizhou, China
| | - Pingping Yang
- College of Agriculture, University of Guizhou, Guiyang, Guizhou, China
| | - Jie Zhang
- China National Tobacco Corporation (CNTC) Key Laboratory of Molecular Genetics, Guizhou Academy of Tobacco Science, Guiyang, Guizhou, China
| | - Eddison Loades
- Department of Biological Sciences, Royal Holloway, University of London, London, United Kingdom
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Stafen CF, Kleine-Vehn J, Maraschin FDS. Signaling events for photomorphogenic root development. TRENDS IN PLANT SCIENCE 2022; 27:1266-1282. [PMID: 36057533 DOI: 10.1016/j.tplants.2022.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 07/26/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
A germinating seedling incorporates environmental signals such as light into developmental outputs. Light is not only a source of energy, but also a central coordinative signal in plants. Traditionally, most research focuses on aboveground organs' response to light; therefore, our understanding of photomorphogenesis in roots is relatively scarce. However, root development underground is highly responsive to light signals from the shoot and understanding these signaling mechanisms will give a better insight into early seedling development. Here, we review the central light signaling hubs and their role in root growth promotion of Arabidopsis thaliana seedlings.
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Affiliation(s)
- Cássia Fernanda Stafen
- PPGBM - Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brazil
| | - Jürgen Kleine-Vehn
- Institute of Biology II, Chair of Molecular Plant Physiology (MoPP), University of Freiburg, Freiburg, Germany; Center for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany
| | - Felipe Dos Santos Maraschin
- PPGBM - Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brazil; Departamento de Botânica, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brazil.
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Nieto C, Catalán P, Luengo LM, Legris M, López-Salmerón V, Davière JM, Casal JJ, Ares S, Prat S. COP1 dynamics integrate conflicting seasonal light and thermal cues in the control of Arabidopsis elongation. SCIENCE ADVANCES 2022; 8:eabp8412. [PMID: 35984876 PMCID: PMC9390991 DOI: 10.1126/sciadv.abp8412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/07/2022] [Indexed: 05/19/2023]
Abstract
As the summer approaches, plants experience enhanced light inputs and warm temperatures, two environmental cues with an opposite morphogenic impact. Key components of this response are PHYTOCHROME B (phyB), EARLY FLOWERING 3 (ELF3), and CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1). Here, we used single and double mutant/overexpression lines to fit a mathematical model incorporating known interactions of these regulators. The fitted model recapitulates thermal growth of all lines used and correctly predicts thermal behavior of others not used in the fit. While thermal COP1 function is accepted to be independent of diurnal timing, our model shows that it acts at temperature signaling only during daytime. Defective response of cop1-4 mutants is epistatic to phyB-9 and elf3-8, indicating that COP1 activity is essential to transduce phyB and ELF3 thermosensory function. Our thermal model provides a unique toolbox to identify best allelic combinations enhancing climate change resilience of crops adapted to different latitudes.
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Affiliation(s)
- Cristina Nieto
- Centro Nacional de Biotecnologia (CNB), CSIC, Darwin 3, 28049 Madrid, Spain
- Centro de Recursos Fitogeneticos y Agricultura Sostenible (CRF-INIA), CSIC, Autovia A2, km 32, 28805 Alcala de Henares, Madrid, Spain
| | - Pablo Catalán
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain
- Department of Mathematics, Universidad Carlos III de Madrid, Avenida de la Universidad 30, 28911 Leganes, Madrid, Spain
| | - Luis Miguel Luengo
- Centro Nacional de Biotecnologia (CNB), CSIC, Darwin 3, 28049 Madrid, Spain
- Centro de Investigación en Agrigenomica (CRAG), CSIC-IRTA-UAB-UB, 08193 Cerdanyola, Barcelona, Spain
| | - Martina Legris
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, 1405 Buenos Aires, Argentina
| | | | | | - Jorge J. Casal
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, 1405 Buenos Aires, Argentina
- Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura, Facultad de Agronomía, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, 1417 Buenos Aires, Argentina
| | - Saúl Ares
- Centro Nacional de Biotecnologia (CNB), CSIC, Darwin 3, 28049 Madrid, Spain
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain
- Corresponding author. (S.A.); (S.P.)
| | - Salomé Prat
- Centro Nacional de Biotecnologia (CNB), CSIC, Darwin 3, 28049 Madrid, Spain
- Centro de Investigación en Agrigenomica (CRAG), CSIC-IRTA-UAB-UB, 08193 Cerdanyola, Barcelona, Spain
- Corresponding author. (S.A.); (S.P.)
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White DWR. PEAPOD repressors modulate and coordinate developmental responses to light intensity in Arabidopsis. THE NEW PHYTOLOGIST 2022; 235:1470-1485. [PMID: 35510737 PMCID: PMC9544094 DOI: 10.1111/nph.18198] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/27/2022] [Indexed: 06/09/2023]
Abstract
Higher plants adapt to different light intensities by altering hypocotyl elongation, stomatal density, seed size, and flowering time. Despite the importance of this developmental plasticity, knowledge of the underlying genetic and molecular mechanisms modulating and coordinating responses to light intensity remains incomplete. Here, I report that in Arabidopsis the PEAPOD (PPD) repressors PPD1 and PPD2 prevent exaggerated responses to light intensity. Genetic and transcriptome analyses, of a ppd deletion mutant and a PPD1 overexpression genotype, were used to identify how PPD repressors modulate the light signalling network. A ppd1/ppd2 deletion mutant has elongated hypocotyls, elevated stomatal density, enlarged seed, and delayed flowering, whereas overexpression of PPD1 results in the reverse. Transcription of both PPD1 and PPD2, upregulated in low light and downregulated in higher light, is activated by PHYTOCHROME INTERACTING FACTOR 4. I found PPDs modulate light signalling by negative regulation of SUPPRESSOR OF phyA-105 (SPA1) transcription. Whereas PPDs coordinate many of the responses to light intensity - hypocotyl elongation, flowering time, and stomatal density - by repression/de-repression of SPA1, PPD regulation of seed size occurs independent of SPA1. In conclusion PPD repressors modulate and coordinate developmental responses to light intensity by altering light signal transduction.
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Affiliation(s)
- Derek W. R. White
- School of Natural SciencesMassey UniversityPalmerston North4442New Zealand
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7
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Su L, Zhou P, Guo L, Jia X, Wang S, Gao J, Li H, Liu B, Song M, Yang J. Arabidopsis SPA2 represses seedling de-etiolation under multiple light conditions. PLANT DIRECT 2022; 6:e403. [PMID: 35662851 PMCID: PMC9148924 DOI: 10.1002/pld3.403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/05/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
In Arabidopsis, phytochrome (phy) A, phyB, and cryptochrome 1 (cry1) are representative far-red, red, and blue light photoreceptors, respectively. Members of the SUPPRESSOR OF PHYA-105 (SPA) protein family (SPA1-SPA4) form E3 ubiquitin ligase complexes with CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1), which mediates the degradation of photomorphogenesis-promoting factors to desensitize light signaling. SPA2 has been reported to promote seedling etiolation in the dark. However, the unique roles of SPA2 and its three functional domains in suppressing photomorphogenesis under different light conditions are largely unknown. Here, we demonstrate that overexpression of the full-length or the central coiled-coil and C-terminal WD-repeat domains of SPA2 cause hyper-etiolation phenotypes under several light conditions. The SPA2 central coiled-coil and C-terminal WD-repeat domains are necessary and sufficient for repressing seedling de-etiolation, cotyledon unfolding, and promoting hypocotyl negative gravitropism under several light conditions. Furthermore, phyA, phyB, cry1, and COP1 repress protein accumulation or nuclear translocation of SPA2 through direct interactions with its kinase-like and coiled-coil domains located in the N-terminus in response to far-red, red, and blue light treatments, respectively. Taken together, our results demonstrate that SPA2 functions under multiple light conditions; moreover, light-activated photoreceptors rapidly suppress SPA2 activity via direct interactions in response to different light treatments.
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Affiliation(s)
- Liang Su
- Institute of Radiation TechnologyBeijing Academy of Science and TechnologyBeijingChina
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
| | - Peng Zhou
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
- China Agricultural Science and Technology PressBeijingChina
| | - Lin Guo
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
| | - Xiaolin Jia
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, and Center for Crop Genome EngineeringHenan Agricultural UniversityZhengzhouChina
| | - Shaoci Wang
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, and Center for Crop Genome EngineeringHenan Agricultural UniversityZhengzhouChina
| | - Jianwei Gao
- Shandong Branch of National Vegetable Improvement Center, Institute of Vegetable ResearchShandong Academy of Agricultural SciencesJinanChina
| | - Hongyu Li
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
| | - Bin Liu
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
| | - Meifang Song
- Institute of Radiation TechnologyBeijing Academy of Science and TechnologyBeijingChina
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
| | - Jianping Yang
- Institute of Crop ScienceChinese Academy of Agricultural SciencesBeijingChina
- College of Agronomy, State Key Laboratory of Wheat and Maize Crop Science, and Center for Crop Genome EngineeringHenan Agricultural UniversityZhengzhouChina
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8
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Ponnu J, Hoecker U. Signaling Mechanisms by Arabidopsis Cryptochromes. FRONTIERS IN PLANT SCIENCE 2022; 13:844714. [PMID: 35295637 PMCID: PMC8918993 DOI: 10.3389/fpls.2022.844714] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 02/04/2022] [Indexed: 05/29/2023]
Abstract
Cryptochromes (CRYs) are blue light photoreceptors that regulate growth, development, and metabolism in plants. In Arabidopsis thaliana (Arabidopsis), CRY1 and CRY2 possess partially redundant and overlapping functions. Upon exposure to blue light, the monomeric inactive CRYs undergo phosphorylation and oligomerization, which are crucial to CRY function. Both the N- and C-terminal domains of CRYs participate in light-induced interaction with multiple signaling proteins. These include the COP1/SPA E3 ubiquitin ligase, several transcription factors, hormone signaling intermediates and proteins involved in chromatin-remodeling and RNA N6 adenosine methylation. In this review, we discuss the mechanisms of Arabidopsis CRY signaling in photomorphogenesis and the recent breakthroughs in Arabidopsis CRY research.
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Affiliation(s)
| | - Ute Hoecker
- *Correspondence: Ute Hoecker, , orcid.org/0000-0002-5636-9777
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9
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Yang C, Yan W, Chang H, Sun C. Arabidopsis CIA2 and CIL have distinct and overlapping functions in regulating chloroplast and flower development. PLANT DIRECT 2022; 6:e380. [PMID: 35106435 PMCID: PMC8786619 DOI: 10.1002/pld3.380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/14/2021] [Accepted: 12/26/2021] [Indexed: 05/05/2023]
Abstract
Arabidopsis CHLOROPLAST IMPORT APPARATUS 2 (CIA2) and its paralogous protein CIA2-LIKE (CIL) are nuclear transcription factors containing a C-terminal CCT motif. CIA2 promotes the expression of nuclear genes encoding chloroplast-localized translocons and ribosomal proteins, thereby increasing the efficiency of protein import and synthesis in chloroplasts. We have previously reported that CIA2 and CIL form a homodimer or heterodimer through their C-terminal sequences and interact with other nuclear proteins, such as CONSTANS (CO), via their N-terminal sequences, but the function of CIL had remained unclear. In this study, we verified through transgenic cia2 mutant plants expressing the CIL coding sequence that CIL is partially functionally redundant to CIA2 during vegetative growth. We also compared phenotypes and gene expression profiles of wildtype Col-0, cia2, cil, and cia2/cil mutants. Our results indicate that CIA2 and CIL coordinate chloroplast biogenesis and function mainly by upregulating the expression of the nuclear factor GOLDEN2-LIKE 1 (GLK1) and chloroplast transcription-, translation-, protein import-, and photosynthesis-related genes, with CIA2 playing a more crucial role. Furthermore, we compared flowering phenotypes in single, double, and triple mutant plants of co, cia2, and cil. We found that CIA2 and CIL participate in modulating long-day floral development. Notably, CIA2 increases flower number and height of the inflorescence main axis, whereas CIL promotes flowering.
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Affiliation(s)
- Chun‐Yen Yang
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
| | - Wen‐You Yan
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
| | - Hsin‐Yen Chang
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
| | - Chih‐Wen Sun
- Department of Life SciencesNational Taiwan Normal UniversityTaipeiTaiwan
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10
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Kerner K, Nagano S, Lübbe A, Hoecker U. Functional comparison of the WD-repeat domains of SPA1 and COP1 in suppression of photomorphogenesis. PLANT, CELL & ENVIRONMENT 2021; 44:3273-3282. [PMID: 34251043 DOI: 10.1111/pce.14148] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
The Arabidopsis COP1/SPA complex acts as a cullin4-based E3 ubiquitin ligase to suppress photomorphogenesis in darkness. It is a tetrameric complex of two COP1 and two SPA proteins. Both COP1 and SPA are essential for the activity of this complex, and they both contain a C-terminal WD-repeat domain responsible for substrate recruitment and binding of DDB1. Here, we used a WD domain swap-approach to address the cooperativity of COP1 and SPA proteins. We found that expression of a chimeric COP1 carrying the WD-repeat domain of SPA1 mostly complemented the cop1-4-mutant phenotype in darkness, indicating that the WD repeat of SPA1 can replace the WD repeat of COP1. In the light, SPA1-WD partially substituted for COP1-WD. In contrast, expression of a chimeric SPA1 protein carrying the WD repeat of COP1 did not rescue the spa-mutant phenotype. Together, our findings demonstrate that a SPA1-type WD repeat is essential for COP1/SPA activity, while a COP1-type WD is in part dispensible. Moreover, a complex with four SPA1-WDs is more active than a complex with only two SPA1-WDs. A homology model of SPA1-WD based on the crystal structure of COP1-WD uncovered two insertions and several amino acid substitutions at the predicted substrate-binding pocket of SPA1-WD.
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Affiliation(s)
- Konstantin Kerner
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Soshichiro Nagano
- Institute for Plant Physiology, Justus Liebig-University Gießen, Gießen, Germany
| | - Annika Lübbe
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Ute Hoecker
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
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11
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Ahmad Z, Balcerowicz M. Shining light on molecular details of SPA2, a repressor of photomorphogenesis. PLANT PHYSIOLOGY 2021; 187:17-18. [PMID: 34618150 PMCID: PMC8418397 DOI: 10.1093/plphys/kiab233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 05/02/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Zaki Ahmad
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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12
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Schenk T, Trimborn L, Chen S, Schenkel C, Hoecker U. Light-induced degradation of SPA2 via its N-terminal kinase domain is required for photomorphogenesis. PLANT PHYSIOLOGY 2021; 187:276-288. [PMID: 33822236 PMCID: PMC8418447 DOI: 10.1093/plphys/kiab156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) and members of the SUPPRESSOR OF PHYTOCHROMEA-105 (SPA) protein family form an E3 ubiquitin ligase that suppresses light signaling in darkness by polyubiquitinating positive regulators of the light response. COP1/SPA is inactivated by light to allow photomorphogenesis to proceed. Mechanisms of inactivation include light-induced degradation of SPA1 and, in particular, SPA2, corresponding to a particularly efficient inactivation of COP1/SPA2 by light. Here, we show that SPA3 and SPA4 proteins are stable in the light, indicating that light-induced destabilization is specific to SPA1 and SPA2, possibly related to the predominant function of SPA1 and SPA2 in dark-grown etiolating seedlings. SPA2 degradation involves cullin and the COP10-DEETIOLATED-DAMAGED-DNA BINDING PROTEIN (DDB1) CDD complex, besides COP1. Consistent with this finding, light-induced SPA2 degradation required the DDB1-interacting Trp-Asp (WD)-repeat domain of SPA2. Deletion of the N-terminus of SPA2 containing the kinase domain led to strong stabilization of SPA2 in darkness and fully abolished light-induced degradation of SPA2. This prevented seedling de-etiolation even in very strong far-red and blue light and reduced de-etiolation in red light, indicating destabilization of SPA2 through its N-terminal domain is essential for light response. SPA2 is exclusively destabilized by phytochrome A in far-red and blue light. However, deletion of the N-terminal domain of SPA2 did not abolish SPA2-phytochrome A interaction in yeast nor in vivo. Our domain mapping suggests there are two SPA2-phytochrome A interacting domains, the N-terminal domain and the WD-repeat domain. Conferring a light-induced SPA2-phyA interaction only via the WD-repeat domain may thus not lead to COP1/SPA2 inactivation.
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Affiliation(s)
- Tobias Schenk
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, Cologne 50674, Germany
| | - Laura Trimborn
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, Cologne 50674, Germany
| | - Song Chen
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, Cologne 50674, Germany
| | - Christian Schenkel
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, Cologne 50674, Germany
| | - Ute Hoecker
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, Cologne 50674, Germany
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Cañibano E, Bourbousse C, García-León M, Garnelo Gómez B, Wolff L, García-Baudino C, Lozano-Durán R, Barneche F, Rubio V, Fonseca S. DET1-mediated COP1 regulation avoids HY5 activity over second-site gene targets to tune plant photomorphogenesis. MOLECULAR PLANT 2021; 14:963-982. [PMID: 33711490 DOI: 10.1101/2020.09.30.318253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/11/2021] [Accepted: 03/05/2021] [Indexed: 05/23/2023]
Abstract
DE-ETIOLATED 1 (DET1) and CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) are two essential repressors of Arabidopsis photomorphogenesis. These proteins can associate with CULLIN4 to form independent CRL4-based E3 ubiquitin ligases that mediate the degradation of several photomorphogenic transcription factors, including ELONGATED HYPOCOTYL 5 (HY5), thereby controlling multiple gene-regulatory networks. Despite extensive biochemical and genetic analyses of their multi-subunit complexes, the functional links between DET1 and COP1 have long remained elusive. Here, we report that DET1 associates with COP1 in vivo, enhances COP1-HY5 interaction, and promotes COP1 destabilization in a process that dampens HY5 protein abundance. By regulating its accumulation, DET1 avoids HY5 association with hundreds of second-site genomic loci, which are also frequently targeted by the skotomorphogenic transcription factor PHYTOCHROME-INTERACTING FACTOR 3. Accordingly, ectopic HY5 chromatin enrichment favors local gene repression and can trigger fusca-like phenotypes. This study therefore shows that DET1-mediated regulation of COP1 stability tunes down the HY5 cistrome, avoiding hyper-photomorphogenic responses that might compromise plant viability.
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Affiliation(s)
- Esther Cañibano
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid 28049, Spain
| | - Clara Bourbousse
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris 75005, France
| | | | - Borja Garnelo Gómez
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Léa Wolff
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris 75005, France
| | | | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China; Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, 72076 Tübingen, Germany
| | - Fredy Barneche
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris 75005, France
| | - Vicente Rubio
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid 28049, Spain.
| | - Sandra Fonseca
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid 28049, Spain.
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14
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Cañibano E, Bourbousse C, García-León M, Garnelo Gómez B, Wolff L, García-Baudino C, Lozano-Durán R, Barneche F, Rubio V, Fonseca S. DET1-mediated COP1 regulation avoids HY5 activity over second-site gene targets to tune plant photomorphogenesis. MOLECULAR PLANT 2021; 14:963-982. [PMID: 33711490 DOI: 10.1016/j.molp.2021.03.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/11/2021] [Accepted: 03/05/2021] [Indexed: 05/14/2023]
Abstract
DE-ETIOLATED 1 (DET1) and CONSTITUTIVE PHOTOMORPHOGENESIS 1 (COP1) are two essential repressors of Arabidopsis photomorphogenesis. These proteins can associate with CULLIN4 to form independent CRL4-based E3 ubiquitin ligases that mediate the degradation of several photomorphogenic transcription factors, including ELONGATED HYPOCOTYL 5 (HY5), thereby controlling multiple gene-regulatory networks. Despite extensive biochemical and genetic analyses of their multi-subunit complexes, the functional links between DET1 and COP1 have long remained elusive. Here, we report that DET1 associates with COP1 in vivo, enhances COP1-HY5 interaction, and promotes COP1 destabilization in a process that dampens HY5 protein abundance. By regulating its accumulation, DET1 avoids HY5 association with hundreds of second-site genomic loci, which are also frequently targeted by the skotomorphogenic transcription factor PHYTOCHROME-INTERACTING FACTOR 3. Accordingly, ectopic HY5 chromatin enrichment favors local gene repression and can trigger fusca-like phenotypes. This study therefore shows that DET1-mediated regulation of COP1 stability tunes down the HY5 cistrome, avoiding hyper-photomorphogenic responses that might compromise plant viability.
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Affiliation(s)
- Esther Cañibano
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid 28049, Spain
| | - Clara Bourbousse
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris 75005, France
| | | | - Borja Garnelo Gómez
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Léa Wolff
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris 75005, France
| | | | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China; Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, 72076 Tübingen, Germany
| | - Fredy Barneche
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSL, Paris 75005, France
| | - Vicente Rubio
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid 28049, Spain.
| | - Sandra Fonseca
- Centro Nacional de Biotecnología, CNB-CSIC, Madrid 28049, Spain.
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15
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Ponnu J, Hoecker U. Illuminating the COP1/SPA Ubiquitin Ligase: Fresh Insights Into Its Structure and Functions During Plant Photomorphogenesis. FRONTIERS IN PLANT SCIENCE 2021; 12:662793. [PMID: 33841486 PMCID: PMC8024647 DOI: 10.3389/fpls.2021.662793] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/04/2021] [Indexed: 05/07/2023]
Abstract
CONSTITUTIVE PHOTOMORPHOGENIC 1 functions as an E3 ubiquitin ligase in plants and animals. Discovered originally in Arabidopsis thaliana, COP1 acts in a complex with SPA proteins as a central repressor of light-mediated responses in plants. By ubiquitinating and promoting the degradation of several substrates, COP1/SPA regulates many aspects of plant growth, development and metabolism. In contrast to plants, human COP1 acts as a crucial regulator of tumorigenesis. In this review, we discuss the recent important findings in COP1/SPA research including a brief comparison between COP1 activity in plants and humans.
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16
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Favero DS, Lambolez A, Sugimoto K. Molecular pathways regulating elongation of aerial plant organs: a focus on light, the circadian clock, and temperature. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:392-420. [PMID: 32986276 DOI: 10.1111/tpj.14996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/11/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Organs such as hypocotyls and petioles rapidly elongate in response to shade and temperature cues, contributing to adaptive responses that improve plant fitness. Growth plasticity in these organs is achieved through a complex network of molecular signals. Besides conveying information from the environment, this signaling network also transduces internal signals, such as those associated with the circadian clock. A number of studies performed in Arabidopsis hypocotyls, and to a lesser degree in petioles, have been informative for understanding the signaling networks that regulate elongation of aerial plant organs. In particular, substantial progress has been made towards understanding the molecular mechanisms that regulate responses to light, the circadian clock, and temperature. Signals derived from these three stimuli converge on the BAP module, a set of three different types of transcription factors that interdependently promote gene transcription and growth. Additional key positive regulators of growth that are also affected by environmental cues include the CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and SUPPRESSOR OF PHYA-105 (SPA) E3 ubiquitin ligase proteins. In this review we summarize the key signaling pathways that regulate the growth of hypocotyls and petioles, focusing specifically on molecular mechanisms important for transducing signals derived from light, the circadian clock, and temperature. While it is clear that similarities abound between the signaling networks at play in these two organs, there are also important differences between the mechanisms regulating growth in hypocotyls and petioles.
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Affiliation(s)
- David S Favero
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | - Alice Lambolez
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan
| | - Keiko Sugimoto
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan
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17
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Kahle N, Sheerin DJ, Fischbach P, Koch LA, Schwenk P, Lambert D, Rodriguez R, Kerner K, Hoecker U, Zurbriggen MD, Hiltbrunner A. COLD REGULATED 27 and 28 are targets of CONSTITUTIVELY PHOTOMORPHOGENIC 1 and negatively affect phytochrome B signalling. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1038-1053. [PMID: 32890447 DOI: 10.1111/tpj.14979] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 07/31/2020] [Accepted: 08/10/2020] [Indexed: 05/23/2023]
Abstract
Phytochromes are red/far-red light receptors in plants involved in the regulation of growth and development. Phytochromes can sense the light environment and contribute to measuring day length; thereby, they allow plants to respond and adapt to changes in the ambient environment. Two well-characterized signalling pathways act downstream of phytochromes and link light perception to the regulation of gene expression. The CONSTITUTIVELY PHOTOMORPHOGENIC 1/SUPPRESSOR OF PHYA-105 (COP1/SPA) E3 ubiquitin ligase complex and the PHYTOCHROME INTERACTING FACTORs (PIFs) are key components of these pathways and repress light responses in the dark. In light-grown seedlings, phytochromes inhibit COP1/SPA and PIF activity and thereby promote light signalling. In a yeast-two-hybrid screen for proteins binding to light-activated phytochromes, we identified COLD-REGULATED GENE 27 (COR27). COR27 and its homologue COR28 bind to phyA and phyB, the two primary phytochromes in seed plants. COR27 and COR28 have been described previously with regard to a function in the regulation of freezing tolerance, flowering and the circadian clock. Here, we show that COR27 and COR28 repress early seedling development in blue, far-red and in particular red light. COR27 and COR28 contain a conserved Val-Pro (VP)-peptide motif, which mediates binding to the COP1/SPA complex. COR27 and COR28 are targeted for degradation by COP1/SPA and mutant versions with a VP to AA amino acid substitution in the VP-peptide motif are stabilized. Overall, our data suggest that COR27 and COR28 accumulate in light but act as negative regulators of light signalling during early seedling development, thereby preventing an exaggerated response to light.
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Affiliation(s)
- Nikolai Kahle
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
| | - David J Sheerin
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
| | - Patrick Fischbach
- Institute of Synthetic Biology and CEPLAS, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Leonie-Alexa Koch
- Institute of Synthetic Biology and CEPLAS, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Philipp Schwenk
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, 79104, Germany
| | - Dorothee Lambert
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
| | - Ryan Rodriguez
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
| | - Konstantin Kerner
- Institute for Plant Sciences, University of Cologne, Cologne, 50674, Germany
| | - Ute Hoecker
- Institute for Plant Sciences, University of Cologne, Cologne, 50674, Germany
| | - Matias D Zurbriggen
- Institute of Synthetic Biology and CEPLAS, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Andreas Hiltbrunner
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, 79104, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, 79104, Germany
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18
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Ponnu J. Molecular mechanisms suppressing COP1/SPA E3 ubiquitin ligase activity in blue light. PHYSIOLOGIA PLANTARUM 2020; 169:418-429. [PMID: 32248530 DOI: 10.1111/ppl.13103] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/19/2020] [Accepted: 03/27/2020] [Indexed: 05/23/2023]
Abstract
Arabidopsis CONSTITUTIVE PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA-105 (COP1/SPA) is an E3 ubiquitin ligase complex that prevents photomorphogenesis in darkness by ubiquitinating and subsequently degrading light-responsive transcription factors. Upon light perception, photoreceptors directly interact with the COP1/SPA complex to suppress its activity. In blue light (450-500 nm of visible spectrum), COP1/SPA activity is inhibited by the cryptochrome photoreceptors (CRY1 and CRY2), FKF1 from the ZEITLUPE family as well as phytochrome A. Together, these photoreceptors regulate vital aspects of plant growth and development from seedling stage to the induction of flowering. This review presents and discusses the recent advances in blue light-mediated suppression of COP1/SPA activity.
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Affiliation(s)
- Jathish Ponnu
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, 50674 Cologne, Germany
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19
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Han X, Huang X, Deng XW. The Photomorphogenic Central Repressor COP1: Conservation and Functional Diversification during Evolution. PLANT COMMUNICATIONS 2020; 1:100044. [PMID: 33367240 PMCID: PMC7748024 DOI: 10.1016/j.xplc.2020.100044] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/19/2020] [Accepted: 04/07/2020] [Indexed: 05/23/2023]
Abstract
Green plants on the earth have evolved intricate mechanisms to acclimatize to and utilize sunlight. In Arabidopsis, light signals are perceived by photoreceptors and transmitted through divergent but overlapping signaling networks to modulate plant photomorphogenic development. COP1 (CONSTITUTIVE PHOTOMORPHOGENIC 1) was first cloned as a central repressor of photomorphogenesis in higher plants and has been extensively studied for over 30 years. It acts as a RING E3 ubiquitin ligase downstream of multiple photoreceptors to target key light-signaling regulators for degradation, primarily as part of large protein complexes. The mammalian counterpart of COP1 is a pluripotent regulator of tumorigenesis and metabolism. A great deal of information on COP1 has been derived from whole-genome sequencing and functional studies in lower green plants, which enables us to illustrate its evolutionary history. Here, we review the current understanding about COP1, with a focus on the conservation and functional diversification of COP1 and its signaling partners in different taxonomic clades.
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Affiliation(s)
- Xue Han
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- Peking University-Southern University of Science and Technology Institute of Plant and Food Science, Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xi Huang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Xing Wang Deng
- State Key Laboratory of Protein and Plant Gene Research, School of Advanced Agricultural Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
- Peking University-Southern University of Science and Technology Institute of Plant and Food Science, Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China
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Cheng MC, Enderle B, Kathare PK, Islam R, Hiltbrunner A, Huq E. PCH1 and PCHL Directly Interact with PIF1, Promote Its Degradation, and Inhibit Its Transcriptional Function during Photomorphogenesis. MOLECULAR PLANT 2020; 13:499-514. [PMID: 32061894 PMCID: PMC7167218 DOI: 10.1016/j.molp.2020.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/18/2019] [Accepted: 02/07/2020] [Indexed: 05/17/2023]
Abstract
PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) and PCH1-LIKE (PCHL) were shown to directly bind to phytochrome B (phyB) and suppress phyB thermal reversion, resulting in plants with dramatically enhanced light sensitivity. Here, we show that PCH1 and PCHL also positively regulate various light responses, including seed germination, hypocotyl gravitropism, and chlorophyll biosynthesis, by physically interacting with PHYTOCHROME INTERACTING FACTOR 1 (PIF1) and CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1). PCH1 and PCHL interact with PIF1 both in the dark and light, and regulate PIF1 abundance. Moreover, PCH1 and PCHL facilitate the physical interaction between phyB and PIF1 in vivo to promote the light-induced degradation of PIF1. PCH1 and PCHL also inhibit the DNA-binding ability of PIF1 to negatively regulate the expressions of PIF1 target genes. In addition, PCH1 and PCHL interact with COP1 and undergo degradation through the 26S proteasome pathway in the dark. Consistently, pch1 suppresses cop1 phenotype in darkness. Collectively, our study reveals a novel mechanism by which PCH1 and PCHL regulate diverse light responses not only by stabilizing phyB Pfr form but also by directly interacting with PIF1 and COP1, providing a molecular understanding of the control of hypocotyl growth by these proteins.
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Affiliation(s)
- Mei-Chun Cheng
- Molecular Biosciences, University of Texas at Austin, NHB 2.616, Stop A5000, 100 East 24th Street, Austin, TX 78712-1095, USA
| | - Beatrix Enderle
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Praveen Kumar Kathare
- Molecular Biosciences, University of Texas at Austin, NHB 2.616, Stop A5000, 100 East 24th Street, Austin, TX 78712-1095, USA
| | - Rafya Islam
- Molecular Biosciences, University of Texas at Austin, NHB 2.616, Stop A5000, 100 East 24th Street, Austin, TX 78712-1095, USA
| | - Andreas Hiltbrunner
- Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Enamul Huq
- Molecular Biosciences, University of Texas at Austin, NHB 2.616, Stop A5000, 100 East 24th Street, Austin, TX 78712-1095, USA.
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Cryptochrome 2 competes with COP1 substrates to repress COP1 ubiquitin ligase activity during Arabidopsis photomorphogenesis. Proc Natl Acad Sci U S A 2019; 116:27133-27141. [PMID: 31822614 DOI: 10.1073/pnas.1909181116] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In plants, the cryptochrome photoreceptors suppress the activity of the COP1/SPA ubiquitin ligase to initiate photomorphogenesis in blue light. Both CRY1 and CRY2 interact with the COP1/SPA complex in a blue light-dependent manner. The mechanisms underlying the inhibition of COP1 activity through direct interactions with photoactivated CRYs are not fully understood. Here we tested the hypothesis that CRY2 inhibits COP1 by displacing the degradation substrates from COP1. To this end, we analyzed the role of a conserved valine-proline (VP) motif in the C-terminal domain of CRY2 (CCT2), which resembles the core COP1-WD40-binding sequences present in the substrates of COP1. We show that the VP motif in CRY2 is essential for the interaction of CRY2 with COP1 in yeast two-hybrid assays and in planta Mutations in the VP motif of CRY2 abolished the CRY2 activity in photomorphogenesis, indicating the importance of VP. The interaction between COP1 and its VP-containing substrate PAP2 was prevented in the presence of coexpressed CRY2, but not in the presence of CRY2 carrying a VP mutation. Thus, since both PAP2 and CRY2 engage VP motifs to bind to COP1, these results demonstrate that CRY2 outcompetes PAP2 for binding to COP1. We further found that the previously unknown interaction between SPA1-WD and CCT2 occurs via the VP motif in CRY2, suggesting structural similarities in the VP-binding pockets of COP1-WD40 and SPA1-WD40 domains. A VP motif present in CRY1 is also essential for binding to COP1. Thus, CRY1 and CRY2 might share this mechanism of COP1 inactivation.
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22
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Artz O, Dickopf S, Ranjan A, Kreiss M, Abraham ET, Boll V, Rensing SA, Hoecker U. Characterization of spa mutants in the moss Physcomitrella provides evidence for functional divergence of SPA genes during the evolution of land plants. THE NEW PHYTOLOGIST 2019; 224:1613-1626. [PMID: 31222750 DOI: 10.1111/nph.16004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 06/10/2019] [Indexed: 06/09/2023]
Abstract
The Arabidopsis COP1/SPA complex is a key repressor of photomorphogenesis that suppresses light signaling in the dark. Both COP1 and SPA proteins are essential components of this complex. Although COP1 also exists in humans, SPA genes are specific to the green lineage. To elucidate the evolution of SPA genes we analyzed SPA functions in the moss Physcomitrella patens by characterizing knockout mutants in the two Physcomitrella SPA genes PpSPAa and PpSPAb. Light-grown PpspaAB double mutants exhibit smaller gametophores than the wild-type. In the dark, PpspaAB mutant gametophores show enhanced continuation of growth but etiolate normally. Gravitropism in the dark is reduced in PpspaAB mutant protonemata. The expression of light-regulated genes is mostly not constitutive in PpspaAB mutants. PpSPA and PpCOP1 interact; PpCOP1 also interacts with the transcription factor PpHY5 and, indeed, PpHY5 is destabilized in dark-grown Physcomitrella. Degradation of PpHY5 in darkness, however, does not require PpSPAa and PpSPAb. The data suggest that COP1/SPA-mediated light signaling is only partially conserved between Arabidopsis and Physcomitrella. Whereas COP1/SPA interaction and HY5 degradation in darkness is conserved, the role of SPA proteins appears to have diverged. PpSPA genes, unlike their Arabidopsis counterparts, are only required to suppress a subset of light responses in darkness.
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Affiliation(s)
- Oliver Artz
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Stephen Dickopf
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Aashish Ranjan
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Melanie Kreiss
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Elena Theres Abraham
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Vanessa Boll
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Stefan A Rensing
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
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23
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UVR8 disrupts stabilisation of PIF5 by COP1 to inhibit plant stem elongation in sunlight. Nat Commun 2019; 10:4417. [PMID: 31562307 PMCID: PMC6764944 DOI: 10.1038/s41467-019-12369-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 09/03/2019] [Indexed: 02/08/2023] Open
Abstract
Alterations in light quality significantly affect plant growth and development. In canopy shade, phytochrome photoreceptors perceive reduced ratios of red to far-red light (R:FR) and initiate stem elongation to enable plants to overtop competitors. This shade avoidance response is achieved via the stabilisation and activation of PHYTOCHROME INTERACTING FACTORs (PIFs) which elevate auxin biosynthesis. UV-B inhibits shade avoidance by reducing the abundance and activity of PIFs, yet the molecular mechanisms controlling PIF abundance in UV-B are unknown. Here we show that the UV-B photoreceptor UVR8 promotes rapid PIF5 degradation via the ubiquitin-proteasome system in a response requiring the N terminus of PIF5. In planta interactions between UVR8 and PIF5 are not observed. We further demonstrate that PIF5 interacts with the E3 ligase COP1, promoting PIF5 stabilisation in light-grown plants. Binding of UVR8 to COP1 in UV-B disrupts this stabilisation, providing a mechanism to rapidly lower PIF5 abundance in sunlight. UV-B light suppresses the shade avoidance response in plants by reducing the abundance of PIF transcription factors by an undefined mechanism. Here the authors show that UV-B perceived by the UVR8 receptor inhibits the shade avoidance response by preventing stabilisation of PIF5 by COP1.
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Podolec R, Ulm R. Photoreceptor-mediated regulation of the COP1/SPA E3 ubiquitin ligase. CURRENT OPINION IN PLANT BIOLOGY 2018; 45:18-25. [PMID: 29775763 DOI: 10.1016/j.pbi.2018.04.018] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/25/2018] [Accepted: 04/29/2018] [Indexed: 05/19/2023]
Abstract
Plants have evolved specific photoreceptors that capture informational cues from sunlight. The phytochrome, cryptochrome, and UVR8 photoreceptors perceive red/far-red, blue/UV-A, and UV-B light, respectively, and control overlapping photomorphogenic responses important for plant growth and development. A major repressor of such photomorphogenic responses is the E3 ubiquitin ligase formed by CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) and SUPPRESSOR OF PHYA-105 (SPA) proteins, which acts by regulating the stability of photomorphogenesis-promoting transcription factors. The direct interaction of light-activated photoreceptors with the COP1/SPA complex represses its activity via nuclear exclusion of COP1, disruption of the COP1-SPA interaction, and/or SPA protein degradation. This process enables plants to integrate different light signals at the level of the COP1/SPA complex to enact appropriate photomorphogenic responses according to the light environment.
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Affiliation(s)
- Roman Podolec
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland; Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland; Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland.
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Sheerin DJ, Hiltbrunner A. Molecular mechanisms and ecological function of far-red light signalling. PLANT, CELL & ENVIRONMENT 2017; 40:2509-2529. [PMID: 28102581 DOI: 10.1111/pce.12915] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 05/18/2023]
Abstract
Land plants possess the ability to sense and respond to far-red light (700-760 nm), which serves as an important environmental cue. Due to the nature of far-red light, it is not absorbed by chlorophyll and thus is enriched in canopy shade and will also penetrate deeper into soil than other visible wavelengths. Far-red light responses include regulation of seed germination, suppression of hypocotyl growth, induction of flowering and accumulation of anthocyanins, which depend on one member of the phytochrome photoreceptor family, phytochrome A (phyA). Here, we review the current understanding of the underlying molecular mechanisms of how plants sense far-red light through phyA and the physiological responses to this light quality. Light-activated phytochromes act on two primary pathways within the nucleus; suppression of the E3 ubiquitin ligase complex CUL4/DDB1COP1/SPA and inactivation of the PHYTOCHROME INTERACTING FACTOR (PIF) family of bHLH transcription factors. These pathways integrate with other signal transduction pathways, including phytohormones, for tissue and developmental stage specific responses. Unlike other phytochromes that mediate red-light responses, phyA is transported from the cytoplasm to the nucleus in far-red light by the shuttle proteins FAR-RED ELONGATED HYPOCOTYL 1 (FHY1) and FHY1-LIKE (FHL). However, additional mechanisms must exist that shift the action of phyA to far-red light; current hypotheses are discussed.
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Affiliation(s)
- David J Sheerin
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Andreas Hiltbrunner
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
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Kim JY, Song JT, Seo HS. COP1 regulates plant growth and development in response to light at the post-translational level. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4737-4748. [PMID: 28992300 DOI: 10.1093/jxb/erx312] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoreceptors perceive different wavelengths of light and transduce light signals downstream via a range of proteins. COP1, an E3 ubiquitin ligase, regulates light signaling by mediating the ubiquitination and subsequent proteasomal degradation of photoreceptors such as phytochromes and cryptochromes, as well as various development-related proteins including other light-responsive proteins. COP1 is itself regulated by direct interactions with several signaling molecules that modulate its activity. The control of photomorphogenesis by COP1 is also regulated by its localization to the cytoplasm in response to light. COP1 thus acts as a tightly regulated switch that determines whether development is skotomorphogenic or photomorphogenic. In this review, we discuss the effects of COP1 on the abundance and activity of various development-related proteins, including photoreceptors, and summarize the regulatory mechanisms that influence COP1 activity and stability in plants.
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Affiliation(s)
- Joo Yong Kim
- Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
| | - Jong Tae Song
- School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Korea
| | - Hak Soo Seo
- Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea
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Holtkotte X, Ponnu J, Ahmad M, Hoecker U. The blue light-induced interaction of cryptochrome 1 with COP1 requires SPA proteins during Arabidopsis light signaling. PLoS Genet 2017; 13:e1007044. [PMID: 28991901 PMCID: PMC5648270 DOI: 10.1371/journal.pgen.1007044] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/19/2017] [Accepted: 09/27/2017] [Indexed: 12/30/2022] Open
Abstract
Plants constantly adjust their growth, development and metabolism to the ambient light environment. Blue light is sensed by the Arabidopsis photoreceptors CRY1 and CRY2 which subsequently initiate light signal transduction by repressing the COP1/SPA E3 ubiquitin ligase. While the interaction between cryptochromes and SPA is blue light-dependent, it was proposed that CRY1 interacts with COP1 constitutively, i.e. also in darkness. Here, our in vivo co-immunoprecipitation experiments suggest that CRY1 and CRY2 form a complex with COP1 only after seedlings were exposed to blue light. No association between COP1 and CRY1 or CRY2 was observed in dark-grown seedlings. Thus, our results suggest that cryptochromes bind the COP1/SPA complex after photoactivation by blue light. In a spa quadruple mutant that is devoid of all four SPA proteins, CRY1 and COP1 did not interact in vivo, neither in dark-grown nor in blue light-grown seedlings. Hence, SPA proteins are required for the high-affinity interaction between CRY1 and COP1 in blue light. Yeast three-hybrid experiments also show that SPA1 enhances the CRY1-COP1 interaction. The coiled-coil domain of SPA1 which is responsible for COP1-binding was necessary to mediate a CRY1-SPA1 interaction in vivo, implying that-in turn-COP1 may be necessary for a CRY1-SPA1 complex formation. Hence, SPA1 and COP1 may act cooperatively in recognizing and binding photoactivated CRY1. In contrast, the blue light-induced association between CRY2 and COP1 was not dependent on SPA proteins in vivo. Similarly, ΔCC-SPA1 interacted with CRY2, though with a much lower affinity than wild-type SPA1. In total, our results demonstrate that CRY1 and CRY2 strongly differ in their blue light-induced interaction with the COP1/SPA complex.
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Affiliation(s)
- Xu Holtkotte
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Jathish Ponnu
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Margaret Ahmad
- UMR 8256 (B2A) CNRA—UPMC, IBPS, Université Pierre et Marie Curie, 9 quai Saint Bernard, Paris, France
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
- * E-mail:
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Holtkotte X, Ponnu J, Ahmad M, Hoecker U. The blue light-induced interaction of cryptochrome 1 with COP1 requires SPA proteins during Arabidopsis light signaling. PLoS Genet 2017. [PMID: 28991901 DOI: 10.1371/journal.pone.1007044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023] Open
Abstract
Plants constantly adjust their growth, development and metabolism to the ambient light environment. Blue light is sensed by the Arabidopsis photoreceptors CRY1 and CRY2 which subsequently initiate light signal transduction by repressing the COP1/SPA E3 ubiquitin ligase. While the interaction between cryptochromes and SPA is blue light-dependent, it was proposed that CRY1 interacts with COP1 constitutively, i.e. also in darkness. Here, our in vivo co-immunoprecipitation experiments suggest that CRY1 and CRY2 form a complex with COP1 only after seedlings were exposed to blue light. No association between COP1 and CRY1 or CRY2 was observed in dark-grown seedlings. Thus, our results suggest that cryptochromes bind the COP1/SPA complex after photoactivation by blue light. In a spa quadruple mutant that is devoid of all four SPA proteins, CRY1 and COP1 did not interact in vivo, neither in dark-grown nor in blue light-grown seedlings. Hence, SPA proteins are required for the high-affinity interaction between CRY1 and COP1 in blue light. Yeast three-hybrid experiments also show that SPA1 enhances the CRY1-COP1 interaction. The coiled-coil domain of SPA1 which is responsible for COP1-binding was necessary to mediate a CRY1-SPA1 interaction in vivo, implying that-in turn-COP1 may be necessary for a CRY1-SPA1 complex formation. Hence, SPA1 and COP1 may act cooperatively in recognizing and binding photoactivated CRY1. In contrast, the blue light-induced association between CRY2 and COP1 was not dependent on SPA proteins in vivo. Similarly, ΔCC-SPA1 interacted with CRY2, though with a much lower affinity than wild-type SPA1. In total, our results demonstrate that CRY1 and CRY2 strongly differ in their blue light-induced interaction with the COP1/SPA complex.
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Affiliation(s)
- Xu Holtkotte
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Jathish Ponnu
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Margaret Ahmad
- UMR 8256 (B2A) CNRA-UPMC, IBPS, Université Pierre et Marie Curie, 9 quai Saint Bernard, Paris, France
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
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Hoecker U. The activities of the E3 ubiquitin ligase COP1/SPA, a key repressor in light signaling. CURRENT OPINION IN PLANT BIOLOGY 2017; 37:63-69. [PMID: 28433946 DOI: 10.1016/j.pbi.2017.03.015] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/17/2017] [Accepted: 03/28/2017] [Indexed: 05/21/2023]
Abstract
Light is a critical signal to integrate plant growth and development with the environment. Downstream of photoreceptors, the E3 ubiquitin ligase COP1/SPA is a key repressor of photomorphogenesis which targets many positive regulators of light signaling, mainly transcription factors, for degradation in darkness. In light-grown plants COP1/SPA activity is repressed, allowing light responses to occur. This review provides an overview on our current knowledge on COP1/SPA repressor function, focusing in particular on the roles of the respective protein domains and the mechanisms of light-induced inactivation of COP1/SPA. Moreover, we summarize how COP1 activity is regulated by other interacting proteins, such as a SUMO E3 ligase and Phytochrome-Interacting Factors (PIFs), as well as by hormones. At last, several novel functions of COP1 that were recently revealed are included.
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Affiliation(s)
- Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, D-50674 Cologne, Germany.
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Holtkotte X, Dieterle S, Kokkelink L, Artz O, Leson L, Fittinghoff K, Hayama R, Ahmad M, Hoecker U. Mutations in the N-terminal kinase-like domain of the repressor of photomorphogenesis SPA1 severely impair SPA1 function but not light responsiveness in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:205-218. [PMID: 27310313 DOI: 10.1111/tpj.13241] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/10/2016] [Accepted: 06/10/2016] [Indexed: 05/23/2023]
Abstract
The COP1/SPA complex is an E3 ubiquitin ligase that acts as a key repressor of photomorphogenesis in dark-grown plants. While both COP1 and the four SPA proteins contain coiled-coil and WD-repeat domains, SPA proteins differ from COP1 in carrying an N-terminal kinase-like domain that is not present in COP1. Here, we have analyzed the effects of deletions and missense mutations in the N-terminus of SPA1 when expressed in a spa quadruple mutant background devoid of any other SPA proteins. Deletion of the large N-terminus of SPA1 severely impaired SPA1 activity in transgenic plants with respect to seedling etiolation, leaf expansion and flowering time. This ΔN SPA1 protein showed a strongly reduced affinity for COP1 in vitro and in vivo, indicating that the N-terminus contributes to COP1/SPA complex formation. Deletion of only the highly conserved 95 amino acids of the kinase-like domain did not severely affect SPA1 function nor interactions with COP1 or cryptochromes. In contrast, missense mutations in this part of the kinase-like domain severely abrogated SPA1 function, suggesting an overriding negative effect of these mutations on SPA1 activity. We therefore hypothesize that the sequence of the kinase-like domain has been conserved during evolution because it carries structural information important for the activity of SPA1 in darkness. The N-terminus of SPA1 was not essential for light responsiveness of seedlings, suggesting that photoreceptors can inhibit the COP1/SPA complex in the absence of the SPA1 N-terminal domain. Together, these results uncover an important, but complex role of the SPA1 N-terminus in the suppression of photomorphogenesis.
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Affiliation(s)
- Xu Holtkotte
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Stefan Dieterle
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Leonie Kokkelink
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Oliver Artz
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Lisa Leson
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Kirsten Fittinghoff
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
| | - Ryosuke Hayama
- Max Planck Institute of Plant Breeding Research and Cluster of Excellence on Plant Sciences (CEPLAS), Carl-von-Linné Weg 10, 50829, Cologne, Germany
| | - Margaret Ahmad
- UMR 8256 (B2A) CNRS - UPMC, IBPS, Université Pierre et Marie Curie, Bat C 3éme étage, 9 quai Saint-Bernard, 75252, Paris, Cedex 05, France
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674, Cologne, Germany
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Menon C, Sheerin DJ, Hiltbrunner A. SPA proteins: SPAnning the gap between visible light and gene expression. PLANTA 2016; 244:297-312. [PMID: 27100111 DOI: 10.1007/s00425-016-2509-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 03/26/2016] [Indexed: 05/23/2023]
Abstract
In this review we focus on the role of SPA proteins in light signalling and discuss different aspects, including molecular mechanisms, specificity, and evolution. The ability of plants to perceive and respond to their environment is key to their survival under ever-changing conditions. The abiotic factor light is of particular importance for plants. Light provides plants energy for carbon fixation through photosynthesis, but also is a source of information for the adaptation of growth and development to the environment. Cryptochromes and phytochromes are major photoreceptors involved in control of developmental decisions in response to light cues, including seed germination, seedling de-etiolation, and induction of flowering. The SPA protein family acts in complex with the E3 ubiquitin ligase COP1 to target positive regulators of light responses for degradation by the 26S proteasome to suppress photomorphogenic development in darkness. Light-activated cryptochromes and phytochromes both repress the function of COP1, allowing accumulation of positive photomorphogenic factors in light. In this review, we highlight the role of the SPA proteins in this process and discuss recent advances in understanding how SPAs link light-activation of photoreceptors and downstream signaling.
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Affiliation(s)
- Chiara Menon
- Faculty of Biology, Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
- Center for Plant Molecular Biology, University of Tübingen, Auf der Morgenstelle 32, 72076, Tübingen, Germany
| | - David J Sheerin
- Faculty of Biology, Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Andreas Hiltbrunner
- Faculty of Biology, Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany.
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Chen S, Wirthmueller L, Stauber J, Lory N, Holtkotte X, Leson L, Schenkel C, Ahmad M, Hoecker U. The functional divergence between SPA1 and SPA2 in Arabidopsis photomorphogenesis maps primarily to the respective N-terminal kinase-like domain. BMC PLANT BIOLOGY 2016; 16:165. [PMID: 27444995 PMCID: PMC4957354 DOI: 10.1186/s12870-016-0854-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/14/2016] [Indexed: 05/23/2023]
Abstract
BACKGROUND Plants have evolved complex mechanisms to adapt growth and development to the light environment. The COP1/SPA complex is a key repressor of photomorphogenesis in dark-grown Arabidopsis plants and acts as an E3 ubiquitin ligase to ubiquitinate transcription factors involved in the light response. In the light, COP1/SPA activity is inhibited by photoreceptors, thereby allowing accumulation of these transcription factors and a subsequent light response. Previous results have shown that the four members of the SPA family exhibit partially divergent functions. In particular, SPA1 and SPA2 strongly differ in their responsiveness to light, while they have indistinguishable activities in darkness. The much higher light-responsiveness of SPA2 is partially explained by the much stronger light-induced degradation of SPA2 when compared to SPA1. Here, we have conducted SPA1/SPA2 domain swap experiments to identify the protein domain(s) responsible for the functional divergence between SPA1 and SPA2. RESULTS We have individually swapped the three domains between SPA1 and SPA2 - the N-terminal kinase-like domain, the coiled-coil domain and the WD-repeat domain - and expressed them in spa mutant Arabidopsis plants. The phenotypes of transgenic seedlings show that the respective N-terminal kinase-like domain is primarily responsible for the respective light-responsiveness of SPA1 and SPA2. Furthermore, the most divergent part of the N-terminal domain was sufficient to confer a SPA1- or SPA2-like activity to the respective SPA protein. The stronger light-induced degradation of SPA2 when compared to SPA1 was also primarily conferred by the SPA2 N-terminal domain. At last, the different affinities of SPA1 and SPA2 for cryptochrome 2 are defined by the N-terminal domain of the respective SPA protein. In contrast, both SPA1 and SPA2 similarly interacted with COP1 in light-grown seedlings. CONCLUSIONS Our results show that the distinct activities and protein stabilities of SPA1 and SPA2 in light-grown seedlings are primarily encoded by their N-terminal kinase-like domains. Similarly, the different affinities of SPA1 and SPA2 for cry2 are explained by their respective N-terminal domain. Hence, after a duplication event during evolution, the N-terminal domains of SPA1 and SPA2 underwent subfunctionalization, possibly to allow optimal adaptation of growth and development to a changing light environment.
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Affiliation(s)
- Song Chen
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
- />Present Address: Department of Botany and Plant Biology, University of Geneva, Sciences III, 30 Quai E. Ansermet, 1211 Geneva 4, Switzerland
| | - Lennart Wirthmueller
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
- />Present Address: Department of Plant Biochemistry, Dahlem Center of Plant Sciences, Freie Universität Berlin, Königin-Luise-Str. 12-16, Berlin, Germany
| | - Johannes Stauber
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Niels Lory
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Xu Holtkotte
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Lisa Leson
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Christian Schenkel
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Margaret Ahmad
- />UMR 8256 (B2A) CNRS - UPMC, IBPS, Université Pierre et Marie Curie, Bat C, 9 quai Saint-Bernard, 75252 Paris Cedex 05, France
| | - Ute Hoecker
- />Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
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Chen S, Lory N, Stauber J, Hoecker U. Photoreceptor Specificity in the Light-Induced and COP1-Mediated Rapid Degradation of the Repressor of Photomorphogenesis SPA2 in Arabidopsis. PLoS Genet 2015; 11:e1005516. [PMID: 26368289 PMCID: PMC4569408 DOI: 10.1371/journal.pgen.1005516] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/19/2015] [Indexed: 11/18/2022] Open
Abstract
The Arabidopsis COP1/SPA E3 ubiquitin ligase is a key negative regulator that represses light signaling in darkness by targeting transcription factors involved in the light response for degradation. The COP1/SPA complex consists of COP1 and members of the four-member SPA protein family (SPA1-SPA4). Genetic analysis indicated that COP1/SPA2 function is particularly strongly repressed by light when compared to complexes carrying the other three SPAs, thereby promoting a light response after exposure of plants to extremely low light. Here, we show that the SPA2 protein is degraded within 5–15 min after exposure of dark-grown seedlings to a pulse of light. Phytochrome photoreceptors are required for the rapid degradation of SPA2 in red, far-red and also in blue light, whereas cryptochromes are not involved in the rapid, blue light-induced reduction in SPA2 protein levels. These results uncover a photoreceptor-specific mechanism of light-induced inhibition of COP1/SPA2 function. Phytochrome A (phyA) is required for the severe blue light responsiveness of spa triple mutants expressing only SPA2, thus confirming the important role of phyA in downregulating SPA2 function in blue light. In blue light, SPA2 forms a complex with cryptochrome 1 (cry1), but not with cryptochrome 2 (cry2) in vivo, indicating that the lack of a rapid blue light response of the SPA2 protein is only in part caused by a failure to interact with cryptochromes. Since SPA1 interacts with both cry1 and cry2, these results provide first molecular evidence that the light-regulation of different SPA proteins diverged during evolution. SPA2 degradation in the light requires COP1 and the COP1-interacting coiled-coil domain of SPA2, supporting that SPA2 is ubiquitinated by COP1. We propose that light perceived by phytochromes causes a switch in the ubiquitination activity of COP1/SPA2 from ubiquitinating downstream substrates to ubiquitinating SPA2, which subsequently causes a repression of COP1/SPA2 function. Plants have evolved photoreceptors that initiate a signaling cascade to adjust growth and development to the ambient light environment. The CUL4-dependent COP1/SPA E3 ubiquitin ligase is a key negative regulator of light signaling whose function is repressed by light. Recent research has identified mechanisms that are common to both phytochrome and cryptochrome photoreceptors. Here, we have identified a mechanism of light-induced COP1/SPA repression that is specific to phytochrome photoreceptors. We show that the SPA2 protein is very rapidly degraded in red, far-red and blue light in a phytochrome-dependent fashion. We further show that SPA2 degradation in the light depends on COP1 and on the interaction of SPA2 with COP1. Hence, our results suggest a light-induced degradation of SPA2, but not of COP1, by the COP1/SPA2 ubiquitin ligase. The human ortholog of COP1, which functions without the plant-specific SPA proteins, is known to be regulated by autodegradation following DNA damage. Hence, autodegradation of components of this E3 ligase is a regulatory mechanism used in both humans and plants.
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Affiliation(s)
- Song Chen
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Niels Lory
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Johannes Stauber
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Cologne, Germany
- * E-mail:
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34
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Ordoñez-Herrera N, Fackendahl P, Yu X, Schaefer S, Koncz C, Hoecker U. A cop1 spa mutant deficient in COP1 and SPA proteins reveals partial co-action of COP1 and SPA during Arabidopsis post-embryonic development and photomorphogenesis. MOLECULAR PLANT 2015; 8:479-81. [PMID: 25667004 DOI: 10.1016/j.molp.2014.11.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 11/26/2014] [Accepted: 11/27/2014] [Indexed: 05/23/2023]
Affiliation(s)
- Natalia Ordoñez-Herrera
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674 Cologne, Germany
| | - Petra Fackendahl
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674 Cologne, Germany
| | - Xu Yu
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674 Cologne, Germany
| | - Sabine Schaefer
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné Weg 10, 50829 Cologne, Germany
| | - Csaba Koncz
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné Weg 10, 50829 Cologne, Germany; Institute of Plant Biology, Biological Research Center of Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Strasse 47b, 50674 Cologne, Germany.
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Meng LS, Liu A. Light signaling induces anthocyanin biosynthesis via AN3 mediated COP1 expression. PLANT SIGNALING & BEHAVIOR 2015; 10:e1001223. [PMID: 26357851 PMCID: PMC4883971 DOI: 10.1080/15592324.2014.1001223] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/17/2014] [Indexed: 05/24/2023]
Abstract
Light signaling plays a pivotal role in controlling plant morphogenesis, metabolism, growth and development. The central process of light signaling pathway is to build the link between light signals and the expression of genes involved. Although studies focused on light signaling toward metabolism have been documented well in the past several decades, most regulation networks of light signaling in a specific metabolic production largely remained unknown. Anthocyanin accumulation in plant tissues depends on the availability of light signals, but only little is known about the potential regulation network underlying light signal controls anthocyanin biosynthesis. Here, we briefly review the recent progress on the light-triggered anthocyanin biosynthesis via ANGUSTIFOLIA3 (AN3) and CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) network in Arabidopsis.
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Affiliation(s)
- Lai-Sheng Meng
- Kunming Institute of Botany; Chinese Academy of Sciences; Kunming, China
| | - Aizhong Liu
- Kunming Institute of Botany; Chinese Academy of Sciences; Kunming, China
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Balcerowicz M, Ranjan A, Rupprecht L, Fiene G, Hoecker U. Auxin represses stomatal development in dark-grown seedlings via Aux/IAA proteins. Development 2014; 141:3165-76. [DOI: 10.1242/dev.109181] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Stomatal development is tightly regulated through internal and external factors that are integrated by a complex signalling network. Light represents an external factor that strongly promotes stomata formation. Here, we show that auxin-resistant aux/iaa mutants, e.g. axr3-1, exhibit a de-repression of stomata differentiation in dark-grown seedlings. The higher stomatal index in dark-grown axr3-1 mutants when compared with the wild type is due to increased cell division in the stomatal lineage. Excessive stomata in dark-grown seedlings were also observed in mutants defective in auxin biosynthesis or auxin perception and in seedlings treated with the polar auxin transport inhibitor NPA. Consistent with these findings, exogenous auxin repressed stomata formation in light-grown seedlings. Taken together, these results indicate that auxin is a negative regulator of stomatal development in dark-grown seedlings. Epistasis analysis revealed that axr3-1 acts genetically upstream of the bHLH transcription factors SPCH, MUTE and FAMA, as well as the YDA MAP kinase cascade, but in parallel with the repressor of photomorphogenesis COP1 and the receptor-like protein TMM. The effect of exogenous auxin required the ER family of leucine-rich repeat receptor-like kinases, suggesting that auxin acts at least in part through the ER family. Expression of axr3-1 in the stomatal lineage was insufficient to alter the stomatal index, implying that cell-cell communication is necessary to mediate the effect of auxin. In summary, our results show that auxin signalling contributes to the suppression of stomatal differentiation observed in dark-grown seedlings.
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Affiliation(s)
- Martin Balcerowicz
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, BioCenter, Zuelpicher Str. 47b, 50674 Cologne, Germany
| | - Aashish Ranjan
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, BioCenter, Zuelpicher Str. 47b, 50674 Cologne, Germany
| | - Laura Rupprecht
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, BioCenter, Zuelpicher Str. 47b, 50674 Cologne, Germany
| | - Gabriele Fiene
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, BioCenter, Zuelpicher Str. 47b, 50674 Cologne, Germany
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, BioCenter, Zuelpicher Str. 47b, 50674 Cologne, Germany
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Ranjan A, Dickopf S, Ullrich KK, Rensing SA, Hoecker U. Functional analysis of COP1 and SPA orthologs from Physcomitrella and rice during photomorphogenesis of transgenic Arabidopsis reveals distinct evolutionary conservation. BMC PLANT BIOLOGY 2014; 14:178. [PMID: 24985152 PMCID: PMC4091655 DOI: 10.1186/1471-2229-14-178] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/24/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Plants have evolved light sensing mechanisms to optimally adapt their growth and development to the ambient light environment. The COP1/SPA complex is a key negative regulator of light signaling in the well-studied dicot Arabidopsis thaliana. COP1 and members of the four SPA proteins are part of an E3 ubiquitin ligase that acts in darkness to ubiquitinate several transcription factors involved in light responses, thereby targeting them for degradation by the proteasome. While COP1 is also found in humans, SPA proteins appear specific to plants. Here, we have functionally addressed evolutionary conservation of COP1 and SPA orthologs from the moss Physcomitrella, the monocot rice and the dicot Arabidopsis. RESULTS To this end, we analyzed the activities of COP1- and SPA-like proteins from Physcomitrella patens and rice when expressed in Arabidopsis. Expression of rice COP1 and Physcomitrella COP1 protein sequences predominantly complemented all phenotypic aspects of the viable, hypomorphic cop1-4 mutant and the null, seedling-lethal cop1-5 mutant of Arabidopsis: rice COP1 fully rescued the constitutive-photomorphogenesis phenotype in darkness and the leaf expansion defect of cop1 mutants, while it partially restored normal photoperiodic flowering in cop1. Physcomitrella COP1 partially restored normal seedling growth and flowering time, while it fully restored normal leaf expansion in the cop1 mutants. In contrast, expression of a SPA ortholog from Physcomitrella (PpSPAb) in Arabidopsis spa mutants did not rescue any facet of the spa mutant phenotype, suggesting that the PpSPAb protein is not functionally conserved or that the Arabidopsis function evolved after the split of mosses and seed plants. The SPA1 ortholog from rice (OsSPA1) rescued the spa mutant phenotype in dark-grown seedlings, but did not complement any spa mutant phenotype in light-grown seedlings or in adult plants. CONCLUSION Our results show that COP1 protein sequences from Physcomitrella, rice and Arabidopsis have been functionally conserved during evolution, while the SPA proteins showed considerable functional divergence. This may - at least in part - reflect the fact that COP1 is a single copy gene in seed plants, while SPA proteins are encoded by a small gene family of two to four members with possibly sub- or neofunctionalized tasks.
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Affiliation(s)
- Aashish Ranjan
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
- Present addresss: Life Sciences Addition #2237, Section of Plant Biology, UC Davis, One Shields Ave, Davis, CA 95616, USA
| | - Stephen Dickopf
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
| | - Kristian K Ullrich
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Stefan A Rensing
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
| | - Ute Hoecker
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany
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Maier A, Schrader A, Kokkelink L, Falke C, Welter B, Iniesto E, Rubio V, Uhrig JF, Hülskamp M, Hoecker U. 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. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 74:638-51. [PMID: 23425305 DOI: 10.1111/tpj.12153] [Citation(s) in RCA: 243] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/07/2013] [Accepted: 02/12/2013] [Indexed: 05/19/2023]
Abstract
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.
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Affiliation(s)
- Alexander Maier
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, BioCenter, Zülpicher Str. 47b, 50674, Cologne, Germany
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Debrieux D, Trevisan M, Fankhauser C. Conditional involvement of constitutive photomorphogenic1 in the degradation of phytochrome A. PLANT PHYSIOLOGY 2013; 161:2136-45. [PMID: 23391578 PMCID: PMC3613482 DOI: 10.1104/pp.112.213280] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/05/2013] [Indexed: 05/20/2023]
Abstract
All higher plants possess multiple phytochrome photoreceptors, with phytochrome A (phyA) being light labile and other members of the family being relatively light stable (phyB-phyE in Arabidopsis [Arabidopsis thaliana]). phyA also differs from other members of the family because it enables plants to deetiolate in far-red light-rich environments typical of dense vegetational cover. Later in development, phyA counteracts the shade avoidance syndrome. Light-induced degradation of phyA favors the establishment of a robust shade avoidance syndrome and was proposed to be important for phyA-mediated deetiolation in far-red light. phyA is ubiquitylated and targeted for proteasome-mediated degradation in response to light. Cullin1 and the ubiquitin E3 ligase constitutive photomorphogenic1 (COP1) have been implicated in this process. Here, we systematically analyze the requirement of cullins in this process and show that only CULLIN1 plays an important role in light-induced phyA degradation. In addition, the role of COP1 in this process is conditional and depends on the presence of metabolizable sugar in the growth medium. COP1 acts with SUppressor of phytochrome A (SPA) proteins. Unexpectedly, the light-induced decline of phyA levels is reduced in spa mutants irrespective of the growth medium, suggesting a COP1-independent role for SPA proteins.
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Arsovski AA, Galstyan A, Guseman JM, Nemhauser JL. Photomorphogenesis. THE ARABIDOPSIS BOOK 2012; 10:e0147. [PMID: 22582028 PMCID: PMC3350170 DOI: 10.1199/tab.0147] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
As photoautotrophs, plants are exquisitely sensitive to their light environment. Light affects many developmental and physiological responses throughout plants' life histories. The focus of this chapter is on light effects during the crucial period of time between seed germination and the development of the first true leaves. During this time, the seedling must determine the appropriate mode of action to best achieve photosynthetic and eventual reproductive success. Light exposure triggers several major developmental and physiological events. These include: growth inhibition and differentiation of the embryonic stem (hypocotyl); maturation of the embryonic leaves (cotyledons); and establishment and activation of the stem cell population in the shoot and root apical meristems. Recent studies have linked a number of photoreceptors, transcription factors, and phytohormones to each of these events.
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Affiliation(s)
- Andrej A. Arsovski
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800
| | - Anahit Galstyan
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800
| | - Jessica M. Guseman
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800
| | - Jennifer L. Nemhauser
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800
- Address correspondence to
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41
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Chen M, Chory J. Phytochrome signaling mechanisms and the control of plant development. Trends Cell Biol 2011; 21:664-71. [PMID: 21852137 DOI: 10.1016/j.tcb.2011.07.002] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/01/2011] [Accepted: 07/05/2011] [Indexed: 11/18/2022]
Abstract
As they emerge from the ground, seedlings adopt a photosynthetic lifestyle, which is accompanied by dramatic changes in morphology and global alterations in gene expression that optimizes the plant body plan for light capture. Phytochromes are red and far-red photoreceptors that play a major role during photomorphogenesis, a complex developmental program that seedlings initiate when they first encounter light. The earliest phytochrome signaling events after excitation by red light include their rapid translocation from the cytoplasm to subnuclear bodies (photobodies) that contain other proteins involved in photomorphogenesis, including a number of transcription factors and E3 ligases. In the light, phytochromes and negatively acting transcriptional regulators that interact directly with phytochromes are destabilized, whereas positively acting transcriptional regulators are stabilized. Here, we discuss recent advances in our knowledge of the mechanisms linking phytochrome photoactivation in the cytoplasm and transcriptional regulation in the nucleus.
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Affiliation(s)
- Meng Chen
- Department of Biology, Duke University, Durham, NC 27708, USA.
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Fankhauser C, Ulm R. Light-regulated interactions with SPA proteins underlie cryptochrome-mediated gene expression. Genes Dev 2011; 25:1004-9. [PMID: 21576261 PMCID: PMC3093115 DOI: 10.1101/gad.2053911] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cryptochromes are a class of photosensory receptors that control important processes in animals and plants primarily by regulating gene expression. How photon absorption by cryptochromes leads to changes in gene expression has remained largely elusive. Three recent studies, including Lian and colleagues (pp. 1023-1028) and Liu and colleagues (pp. 1029-1034) in this issue of Genes & Development, demonstrate that the interaction of light-activated Arabidopsis cryptochromes with a class of regulatory components of E3 ubiquitin ligase complexes leads to environmentally controlled abundance of transcriptional regulators.
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Affiliation(s)
- Christian Fankhauser
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
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Ranjan A, Fiene G, Fackendahl P, Hoecker U. The Arabidopsis repressor of light signaling SPA1 acts in the phloem to regulate seedling de-etiolation, leaf expansion and flowering time. Development 2011; 138:1851-62. [DOI: 10.1242/dev.061036] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Plants adjust their growth and development in response to the ambient light environment. These light responses involve systemic signals that coordinate differentiation of different tissues and organs. Here, we have investigated the function of the key repressor of photomorphogenesis SPA1 in different tissues of the plant by expressing GUS-SPA1 under the control of tissue-specific promoters in a spa mutant background. We show that SPA1 expression in the phloem vasculature is sufficient to rescue the spa1 mutant phenotype in dark-grown spa mutant seedlings. Expression of SPA1 in mesophyll, epidermis or root tissues of the seedling, by contrast, has no or only slight effects. In the leaf, SPA1 expression in both the phloem and the mesophyll is required for full complementation of the defect in leaf expansion. SPA1 in phloem and mesophyll tissues affected division and expansion of cells in the epidermal layer, indicating that SPA1 induces non-cell-autonomous responses also in the leaf. Photoperiodic flowering is exclusively controlled by SPA1 expression in the phloem, which is consistent with previous results showing that the direct substrate of the COP1/SPA complex, CONSTANS, also acts in the phloem. Taken together, our results highlight the importance of phloem vascular tissue in coordinating growth and development. Because the SPA1 protein itself is incapable of moving from cell to cell, we suggest that SPA1 regulates the activity of downstream component(s) of light signaling that subsequently act in a non-cell-autonomous manner. SPA1 action in the phloem may also result in mechanical stimuli that affect cell elongation and cell division in other tissues.
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Affiliation(s)
- Aashish Ranjan
- Botanical Institute, Cologne Biocenter, University of Cologne, Zuelpicher Strasse 47b, 50674 Cologne, Germany
| | - Gabriele Fiene
- Botanical Institute, Cologne Biocenter, University of Cologne, Zuelpicher Strasse 47b, 50674 Cologne, Germany
| | - Petra Fackendahl
- Botanical Institute, Cologne Biocenter, University of Cologne, Zuelpicher Strasse 47b, 50674 Cologne, Germany
| | - Ute Hoecker
- Botanical Institute, Cologne Biocenter, University of Cologne, Zuelpicher Strasse 47b, 50674 Cologne, Germany
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