1
|
Madhuri S, Lepetit B, Fürst AH, Kroth PG. A Knockout of the Photoreceptor PtAureo1a Results in Altered Diel Expression of Diatom Clock Components. PLANTS (BASEL, SWITZERLAND) 2024; 13:1465. [PMID: 38891274 PMCID: PMC11174801 DOI: 10.3390/plants13111465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 05/10/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024]
Abstract
Plants and algae use light not only for driving photosynthesis but also to sense environmental cues and to adjust their circadian clocks via photoreceptors. Aureochromes are blue-light-dependent photoreceptors that also function as transcription factors, possessing both a LOV and a bZIP domain. Aureochromes so far have only been detected in Stramenopile algae, which include the diatoms. Four paralogues of aureochromes have been identified in the pennate model diatom Phaeodactylum tricornutum: PtAureo1a, 1b, 1c, and 2. While it was shown recently that diatoms have a diel rhythm, the molecular mechanisms and components regulating it are still largely unknown. Diel gene expression analyses of wild-type P. tricornutum, a PtAureo1a knockout strain, and the respective PtAureo1 complemented line revealed that all four aureochromes have a different diel regulation and that PtAureo1a has a strong co-regulatory influence on its own transcription, as well as on that of other genes encoding different blue-light photoreceptors (CPF1, 2 and 4), proteins involved in photoprotection (Lhcx1), and specific bHLH transcription factors (RITMO1). Some of these genes completely lost their circadian expression in the PtAureo1a KO mutant. Our results suggest a major involvement of aureochromes in the molecular clock of diatoms.
Collapse
Affiliation(s)
| | | | | | - Peter G. Kroth
- Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany; (S.M.); (B.L.); (A.H.F.)
| |
Collapse
|
2
|
Im SH, Lepetit B, Mosesso N, Shrestha S, Weiss L, Nymark M, Roellig R, Wilhelm C, Isono E, Kroth PG. Identification of promoter targets by Aureochrome 1a in the diatom Phaeodactylum tricornutum. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1834-1851. [PMID: 38066674 DOI: 10.1093/jxb/erad478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 12/04/2023] [Indexed: 03/28/2024]
Abstract
Aureochromes (AUREOs) are unique blue light receptors and transcription factors found only in stramenopile algae. While each of the four AUREOs identified in the diatom Phaeodactylum tricornutum may have a specific function, PtAUREO1a has been shown to have a strong impact on overall gene regulation, when light changes from red to blue light conditions. Despite its significance, the molecular mechanism of PtAUREO1a is largely unexplored. To comprehend the overall process of gene regulation by PtAUREO1a, we conducted a series of in vitro and in vivo experiments, including pull-down assays, yeast one-hybrid experiments, and phenotypical characterization using recombinant PtAUREOs and diatom mutant lines expressing a modified PtAureo1a gene. We describe the distinct light absorption properties of four PtAUREOs and the formation of all combinations of their potential dimers. We demonstrate the capability of PtAUREO1a and 1b to activate the genes, diatom-specific cyclin 2, PtAureo1a, and PtAureo1c under both light and dark conditions. Using mutant lines expressing a modified PtAUREO1a protein with a considerably reduced light absorption, we found novel evidence that PtAUREO1a regulates the expression of PtLHCF15, which is essential for red light acclimation. Based on current knowledge, we present a working model of PtAUREO1a gene regulation properties.
Collapse
Affiliation(s)
- Soo Hyun Im
- Plant Ecophysiology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Bernard Lepetit
- Plant Ecophysiology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
- Molecular Stress Physiology, Institute of Biological Sciences, University of Rostock, D-18059 Rostock, Germany
| | - Niccolò Mosesso
- Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Sandeep Shrestha
- Plant Ecophysiology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Laura Weiss
- Plant Ecophysiology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Marianne Nymark
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Robert Roellig
- Institute of Biology, Department of Plant Physiology, University of Leipzig, D-04103 Leipzig, Germany
| | - Christian Wilhelm
- Institute of Biology, Department of Plant Physiology, University of Leipzig, D-04103 Leipzig, Germany
| | - Erika Isono
- Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Peter G Kroth
- Plant Ecophysiology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| |
Collapse
|
3
|
Buck JM, Kroth PG, Lepetit B. Identification of sequence motifs in Lhcx proteins that confer qE-based photoprotection in the diatom Phaeodactylum tricornutum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 108:1721-1734. [PMID: 34651379 DOI: 10.1111/tpj.15539] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/11/2021] [Indexed: 05/08/2023]
Abstract
Photosynthetic organisms in nature often experience light fluctuations. While low light conditions limit the energy uptake by algae, light absorption exceeding the maximal rate of photosynthesis may go along with enhanced formation of potentially toxic reactive oxygen species. To preempt high light-induced photodamage, photosynthetic organisms evolved numerous photoprotective mechanisms. Among these, energy-dependent fluorescence quenching (qE) provides a rapid mechanism to dissipate thermally the excessively absorbed energy. Diatoms thrive in all aquatic environments and thus belong to the most important primary producers on earth. qE in diatoms is provided by a concerted action of Lhcx proteins and the xanthophyll cycle pigment diatoxanthin. While the exact Lhcx activation mechanism of diatom qE is unknown, two lumen-exposed acidic amino acids within Lhcx proteins were proposed to function as regulatory switches upon light-induced lumenal acidification. By introducing a modified Lhcx1 lacking these amino acids into a Phaeodactylum tricornutum Lhcx1-null qE knockout line, we demonstrate that qE is unaffected by these two amino acids. Based on sequence comparisons with Lhcx4, being incapable of providing qE, we perform domain swap experiments of Lhcx4 with Lhcx1 and identify two peptide motifs involved in conferring qE. Within one of these motifs, we identify a tryptophan residue with a major influence on qE establishment. This tryptophan residue is located in close proximity to the diadinoxanthin/diatoxanthin-binding site based on the recently revealed diatom Lhc crystal structure. Our findings provide a structural explanation for the intimate link of Lhcx and diatoxanthin in providing qE in diatoms.
Collapse
Affiliation(s)
- Jochen M Buck
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Peter G Kroth
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| | - Bernard Lepetit
- Plant Ecophysiology, Department of Biology, University of Konstanz, Konstanz, 78457, Germany
| |
Collapse
|
4
|
Ramírez N, Serey M, Illanes A, Piumetti M, Ottone C. Immobilization strategies of photolyases: Challenges and perspectives for DNA repairing application. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 215:112113. [PMID: 33383556 DOI: 10.1016/j.jphotobiol.2020.112113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/27/2020] [Accepted: 12/19/2020] [Indexed: 02/08/2023]
Abstract
Photolyases are enzymes that repair DNA damage caused by solar radiation. Due to their photorepair potential, photolyases added in topical creams and used in medical treatments has allowed to reverse skin damage and prevent the development of different diseases, including actinic keratosis, premature photoaging and cancer. For this reason, research has been oriented to the study of new photolyases performing in extreme environments, where high doses of UV radiation may be a key factor for these enzymes to have perfected their photorepair potential. Generally, the extracted enzymes are first encapsulated and then added to the topical creams to increase their stability. However, other well consolidated immobilization methods are interesting strategies to be studied that may improve the biocatalyst performance. This review aims to go through the different Antarctic organisms that have exhibited photoreactivation activity, explaining the main mechanisms of photolyase DNA photorepair. The challenges of immobilizing these enzymes on porous and nanostructured supports is also discussed. The comparison of the most reported immobilization methods with respect to the structure of photolyases show that both covalent and ionic immobilization methods produced an increase in their stability. Moreover, the use of nanosized materials as photolyase support would permit the incorporation of the biocatalyst into the target cell, which is a technological requirement that photolyase based biocatalysts must fulfill.
Collapse
Affiliation(s)
- Nicolás Ramírez
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2085, Valparaíso, Chile
| | - Marcela Serey
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2085, Valparaíso, Chile
| | - Andrés Illanes
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2085, Valparaíso, Chile
| | - Marco Piumetti
- Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Carminna Ottone
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2085, Valparaíso, Chile.
| |
Collapse
|
5
|
Mann M, Serif M, Wrobel T, Eisenhut M, Madhuri S, Flachbart S, Weber APM, Lepetit B, Wilhelm C, Kroth PG. The Aureochrome Photoreceptor PtAUREO1a Is a Highly Effective Blue Light Switch in Diatoms. iScience 2020; 23:101730. [PMID: 33235981 PMCID: PMC7670200 DOI: 10.1016/j.isci.2020.101730] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/30/2020] [Accepted: 10/21/2020] [Indexed: 02/08/2023] Open
Abstract
Aureochromes represent a unique type of blue light photoreceptors that possess a blue light sensing flavin-binding LOV-domain and a DNA-binding bZIP domain, thus being light-driven transcription factors. The diatom Phaeodactylum tricornutum, a member of the essential marine primary producers, possesses four aureochromes (PtAUREO1a, 1b, 1c, 2). Here we show a dramatic change in the global gene expression pattern of P. tricornutum wild-type cells after a shift from red to blue light. About 75% of the genes show significantly changed transcript levels already after 10 and 60 min of blue light exposure, which includes genes of major transcription factors as well as other photoreceptors. Very surprisingly, this light-induced regulation of gene expression is almost completely inhibited in independent PtAureo1a knockout lines. Such a massive and fast transcriptional change depending on one single photoreceptor is so far unprecedented. We conclude that PtAUREO1a plays a key role in diatoms upon blue light exposure. Blue light induces a very fast transcriptional response in the diatom P. tricornutum This strong response is almost completely inhibited when Aureochrome 1a is absent The results imply a key role of PtAureo1a in blue light-induced responses in diatoms
Collapse
Affiliation(s)
- Marcus Mann
- Institut für Biologie, Universität Leipzig, 04009 Leipzig, Germany
| | - Manuel Serif
- Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany
| | - Thomas Wrobel
- Institut für Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Marion Eisenhut
- Institut für Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Shvaita Madhuri
- Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany
| | - Samantha Flachbart
- Institut für Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Andreas P M Weber
- Institut für Biochemie der Pflanzen, Cluster of Excellence on Plant Science (CEPLAS), Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Bernard Lepetit
- Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany
| | | | - Peter G Kroth
- Fachbereich Biologie, Universität Konstanz, 78457 Konstanz, Germany
| |
Collapse
|
6
|
Buck JM, Sherman J, Bártulos CR, Serif M, Halder M, Henkel J, Falciatore A, Lavaud J, Gorbunov MY, Kroth PG, Falkowski PG, Lepetit B. Lhcx proteins provide photoprotection via thermal dissipation of absorbed light in the diatom Phaeodactylum tricornutum. Nat Commun 2019; 10:4167. [PMID: 31519883 PMCID: PMC6744471 DOI: 10.1038/s41467-019-12043-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/16/2019] [Indexed: 11/15/2022] Open
Abstract
Diatoms possess an impressive capacity for rapidly inducible thermal dissipation of excess absorbed energy (qE), provided by the xanthophyll diatoxanthin and Lhcx proteins. By knocking out the Lhcx1 and Lhcx2 genes individually in Phaeodactylum tricornutum strain 4 and complementing the knockout lines with different Lhcx proteins, multiple mutants with varying qE capacities are obtained, ranging from zero to high values. We demonstrate that qE is entirely dependent on the concerted action of diatoxanthin and Lhcx proteins, with Lhcx1, Lhcx2 and Lhcx3 having similar functions. Moreover, we establish a clear link between Lhcx1/2/3 mediated inducible thermal energy dissipation and a reduction in the functional absorption cross-section of photosystem II. This regulation of the functional absorption cross-section can be tuned by altered Lhcx protein expression in response to environmental conditions. Our results provide a holistic understanding of the rapidly inducible thermal energy dissipation process and its mechanistic implications in diatoms. Photosynthetic organisms can dissipate excess absorbed light energy as heat to avoid photodamage. Here the authors show that induced thermal dissipation in the diatom Phaeodactylum tricornutum Pt4 is Lhcx protein-dependent and correlates with a reduced functional absorption cross-section of photosystem II.
Collapse
Affiliation(s)
- Jochen M Buck
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Jonathan Sherman
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Carolina Río Bártulos
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Manuel Serif
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Marc Halder
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Jan Henkel
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany.,Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland
| | - Angela Falciatore
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Johann Lavaud
- UMI 3376 Takuvik, CNRS/ULaval, Département de Biologie, Pavillon Alexandre-Vachon, Université Laval, Québec (Québec), G1V 0A6, Canada
| | - Maxim Y Gorbunov
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Peter G Kroth
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Paul G Falkowski
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Bernard Lepetit
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany. .,Zukunftskolleg, University of Konstanz, 78457, Konstanz, Germany.
| |
Collapse
|