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Kalvelage J, Wöhlbrand L, Senkler J, Schumacher J, Ditz N, Bischof K, Winklhofer M, Klingl A, Braun HP, Rabus R. Conspicuous chloroplast with light harvesting-photosystem I/II megacomplex in marine Prorocentrum cordatum. PLANT PHYSIOLOGY 2024; 195:306-325. [PMID: 38330164 PMCID: PMC11181951 DOI: 10.1093/plphys/kiae052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/05/2024] [Accepted: 01/06/2024] [Indexed: 02/10/2024]
Abstract
Marine photosynthetic (micro)organisms drive multiple biogeochemical cycles and display a large diversity. Among them, the bloom-forming, free-living dinoflagellate Prorocentrum cordatum CCMP 1329 (formerly P. minimum) stands out with its distinct cell biological features. Here, we obtained insights into the structural properties of the chloroplast and the photosynthetic machinery of P. cordatum using microscopic and proteogenomic approaches. High-resolution FIB/SEM analysis revealed a single large chloroplast (∼40% of total cell volume) with a continuous barrel-like structure, completely lining the inner face of the cell envelope and enclosing a single reticular mitochondrium, the Golgi apparatus, as well as diverse storage inclusions. Enriched thylakoid membrane fractions of P. cordatum were comparatively analyzed with those of the well-studied model-species Arabidopsis (Arabidopsis thaliana) using 2D BN DIGE. Strikingly, P. cordatum possessed a large photosystem-light harvesting megacomplex (>1.5 MDa), which is dominated by photosystems I and II (PSI, PSII), chloroplast complex I, and chlorophyll a-b binding light harvesting complex proteins. This finding parallels the absence of grana in its chloroplast and distinguishes from the predominant separation of PSI and PSII complexes in A. thaliana, indicating a different mode of flux balancing. Except for the core elements of the ATP synthase and the cytb6f-complex, the composition of the other complexes (PSI, PSII, and pigment-binding proteins, PBPs) of P. cordatum differed markedly from those of A. thaliana. Furthermore, a high number of PBPs was detected, accounting for a large share of the total proteomic data (∼65%) and potentially providing P. cordatum with flexible adaptation to changing light regimes.
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Affiliation(s)
- Jana Kalvelage
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Lars Wöhlbrand
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Jennifer Senkler
- Faculty of Natural Sciences, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Julian Schumacher
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Noah Ditz
- Faculty of Natural Sciences, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Kai Bischof
- Faculty Biology/Chemistry, University of Bremen & MARUM, 28359 Bremen, Germany
| | - Michael Winklhofer
- School of Mathematics and Science, Institute of Biology and Environmental Sciences (IBU), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
- Research Center Neurosensory Science, School of Mathematics and Science, Carl von Ossietzky University of Oldenburg, 26129 Oldenburg, Germany
| | - Andreas Klingl
- Faculty of Biology, Botany, Ludwig-Maximilians-Universität LMU München, 82152 Planegg-Martinsried, Germany
| | - Hans-Peter Braun
- Faculty of Natural Sciences, Institute of Plant Genetics, Leibniz Universität Hannover, 30419 Hannover, Germany
| | - Ralf Rabus
- School of Mathematics and Science, Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
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Kim RG, Huang W, Findinier J, Bunbury F, Redekop P, Shrestha R, Grismer TS, Vilarrasa-Blasi J, Jinkerson RE, Fakhimi N, Fauser F, Jonikas MC, Onishi M, Xu SL, Grossman AR. Chloroplast Methyltransferase Homolog RMT2 is Involved in Photosystem I Biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.21.572672. [PMID: 38187728 PMCID: PMC10769443 DOI: 10.1101/2023.12.21.572672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Oxygen (O2), a dominant element in the atmosphere and essential for most life on Earth, is produced by the photosynthetic oxidation of water. However, metabolic activity can cause accumulation of reactive O2 species (ROS) and severe cell damage. To identify and characterize mechanisms enabling cells to cope with ROS, we performed a high-throughput O2 sensitivity screen on a genome-wide insertional mutant library of the unicellular alga Chlamydomonas reinhardtii. This screen led to identification of a gene encoding a protein designated Rubisco methyltransferase 2 (RMT2). Although homologous to methyltransferases, RMT2 has not been experimentally demonstrated to have methyltransferase activity. Furthermore, the rmt2 mutant was not compromised for Rubisco (first enzyme of Calvin-Benson Cycle) levels but did exhibit a marked decrease in accumulation/activity of photosystem I (PSI), which causes light sensitivity, with much less of an impact on other photosynthetic complexes. This mutant also shows increased accumulation of Ycf3 and Ycf4, proteins critical for PSI assembly. Rescue of the mutant phenotype with a wild-type (WT) copy of RMT2 fused to the mNeonGreen fluorophore indicates that the protein localizes to the chloroplast and appears to be enriched in/around the pyrenoid, an intrachloroplast compartment present in many algae that is packed with Rubisco and potentially hypoxic. These results indicate that RMT2 serves an important role in PSI biogenesis which, although still speculative, may be enriched around or within the pyrenoid.
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Affiliation(s)
- Rick G. Kim
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Weichao Huang
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Justin Findinier
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Freddy Bunbury
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Petra Redekop
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Ruben Shrestha
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - TaraBryn S Grismer
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | | | - Robert E. Jinkerson
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA
| | - Neda Fakhimi
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Friedrich Fauser
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Martin C. Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Masayuki Onishi
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Shou-Ling Xu
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Arthur R. Grossman
- Department of Biosphere Science and Engineering, Carnegie Institution for Science, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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Findinier J, Joubert LM, Schmid MF, Malkovskiy A, Chiu W, Burlacot A, Grossman AR. Dramatic Changes in Mitochondrial Subcellular Location and Morphology Accompany Activation of the CO 2 Concentrating Mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586705. [PMID: 38585955 PMCID: PMC10996633 DOI: 10.1101/2024.03.25.586705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Dynamic changes in intracellular ultrastructure can be critical for the ability of organisms to acclimate to environmental conditions. Microalgae, which are responsible for ~50% of global photosynthesis, compartmentalize their Rubisco into a specialized structure known as the pyrenoid when the cells experience limiting CO2 conditions; this compartmentalization appears to be a component of the CO2 Concentrating Mechanism (CCM), which facilitates photosynthetic CO2 fixation as environmental levels of inorganic carbon (Ci) decline. Changes in the spatial distribution of mitochondria in green algae have also been observed under CO2 limiting conditions, although a role for this reorganization in CCM function remains unclear. We used the green microalgae Chlamydomonas reinhardtii to monitor changes in the position and ultrastructure of mitochondrial membranes as cells transition between high CO2 (HC) and Low/Very Low CO2 (LC/VLC). Upon transferring cells to VLC, the mitochondria move from a central to a peripheral location, become wedged between the plasma membrane and chloroplast envelope, and mitochondrial membranes orient in parallel tubular arrays that extend from the cell's apex to its base. We show that these ultrastructural changes require protein and RNA synthesis, occur within 90 min of shifting cells to VLC conditions, correlate with CCM induction and are regulated by the CCM master regulator CIA5. The apico-basal orientation of the mitochondrial membrane, but not the movement of the mitochondrion to the cell periphery, is dependent on microtubules and the MIRO1 protein, which is involved in membrane-microtubule interactions. Furthermore, blocking mitochondrial electron transport in VLC acclimated cells reduces the cell's affinity for inorganic carbon. Overall, our results suggest that CIA5-dependent mitochondrial repositioning/reorientation functions in integrating cellular architecture and energetics with CCM activities and invite further exploration of how intracellular architecture can impact fitness under dynamic environmental conditions.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Michael F. Schmid
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Andrey Malkovskiy
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Wah Chiu
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
- Stanford University, Department of Bioengineering, Stanford, CA 94305, USA
| | - Adrien Burlacot
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
| | - Arthur R. Grossman
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
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4
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He S, Crans VL, Jonikas MC. The pyrenoid: the eukaryotic CO2-concentrating organelle. THE PLANT CELL 2023; 35:3236-3259. [PMID: 37279536 PMCID: PMC10473226 DOI: 10.1093/plcell/koad157] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 06/08/2023]
Abstract
The pyrenoid is a phase-separated organelle that enhances photosynthetic carbon assimilation in most eukaryotic algae and the land plant hornwort lineage. Pyrenoids mediate approximately one-third of global CO2 fixation, and engineering a pyrenoid into C3 crops is predicted to boost CO2 uptake and increase yields. Pyrenoids enhance the activity of the CO2-fixing enzyme Rubisco by supplying it with concentrated CO2. All pyrenoids have a dense matrix of Rubisco associated with photosynthetic thylakoid membranes that are thought to supply concentrated CO2. Many pyrenoids are also surrounded by polysaccharide structures that may slow CO2 leakage. Phylogenetic analysis and pyrenoid morphological diversity support a convergent evolutionary origin for pyrenoids. Most of the molecular understanding of pyrenoids comes from the model green alga Chlamydomonas (Chlamydomonas reinhardtii). The Chlamydomonas pyrenoid exhibits multiple liquid-like behaviors, including internal mixing, division by fission, and dissolution and condensation in response to environmental cues and during the cell cycle. Pyrenoid assembly and function are induced by CO2 availability and light, and although transcriptional regulators have been identified, posttranslational regulation remains to be characterized. Here, we summarize the current knowledge of pyrenoid function, structure, components, and dynamic regulation in Chlamydomonas and extrapolate to pyrenoids in other species.
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Affiliation(s)
- Shan He
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08540, USA
| | - Victoria L Crans
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08540, USA
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5
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An Y, Wang D, Du J, Wang X, Xiao J. Pyrenoid: Organelle with efficient CO 2-Concentrating mechanism in algae. JOURNAL OF PLANT PHYSIOLOGY 2023; 287:154044. [PMID: 37392525 DOI: 10.1016/j.jplph.2023.154044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 06/05/2023] [Accepted: 06/18/2023] [Indexed: 07/03/2023]
Abstract
The carbon dioxide emitted by human accounts for only a small fraction of global photosynthesis consumption, half of which is due to microalgae. The high efficiency of algae photosynthesis is attributed to the pyrenoid-based CO2-concentrating mechanism (CCM). The formation of pyrenoid which has a variety of Rubisco-binding proteins mainly depends on liquid-liquid phase separation (LLPS) of Rubisco, a CO2 fixing enzyme. At present, our understanding of pyrenoid at the molecular level mainly stems from studies of the model algae Chlamydomonas reinhardtii. In this article, we summarize the current research on the structure, assembly and application of Chlamydomonas reinhardtii pyrenoids, providing new ideas for improving crop photosynthetic performance and yield.
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Affiliation(s)
- Yaqi An
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
| | - Dong Wang
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
| | - Jingxia Du
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
| | - Xinwei Wang
- College of Agriculture and Forestry, Hebei North University, Zhangjiakou, China.
| | - Jianwei Xiao
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China; Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.
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6
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Findinier J, Grossman AR. Chlamydomonas: Fast tracking from genomics. JOURNAL OF PHYCOLOGY 2023; 59:644-652. [PMID: 37417760 DOI: 10.1111/jpy.13356] [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: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 07/08/2023]
Abstract
Elucidating biological processes has relied on the establishment of model organisms, many of which offer advantageous features such as rapid axenic growth, extensive knowledge of their physiological features and gene content, and the ease with which they can be genetically manipulated. The unicellular green alga Chlamydomonas reinhardtii has been an exemplary model that has enabled many scientific breakthroughs over the decades, especially in the fields of photosynthesis, cilia function and biogenesis, and the acclimation of photosynthetic organisms to their environment. Here, we discuss recent molecular/technological advances that have been applied to C. reinhardtii and how they have further fostered its development as a "flagship" algal system. We also explore the future promise of this alga in leveraging advances in the fields of genomics, proteomics, imaging, and synthetic biology for addressing critical future biological issues.
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Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Science and Engineering, Stanford, California, USA
| | - Arthur R Grossman
- The Carnegie Institution for Science, Biosphere Science and Engineering, Stanford, California, USA
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7
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do Carmo Cesário C, Soares J, Cossolin JFS, Almeida AVM, Bermudez Sierra JJ, de Oliveira Leite M, Nunes MC, Serrão JE, Martins MA, Dos Reis Coimbra JS. Biochemical and morphological characterization of freshwater microalga Tetradesmus obliquus (Chlorophyta: Chlorophyceae). PROTOPLASMA 2022; 259:937-948. [PMID: 34643788 DOI: 10.1007/s00709-021-01712-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
Tetradesmus is a microalgal genus with biotechnological potential due to its rapid production of biomass, which is plenty in proteins, carbohydrates, lipids, and bioactives. However, its morphology and physiology need to be determined to guide better research to optimize the species cultivation and biocompounds processing. Thus, this study describes the biochemistry and morphology of the strain Tetradesmus obliquus BR003, isolated from a sample of freshwater reservoirs in a Brazilian municipality. In the T. obliquus BR003 dry biomass, we identified 61.6% unsaturated fatty acids, and 3.4% saturated fatty acids. Regarding other compounds, 28.50 ± 1.47 g soluble proteins/100 g, 0.14 ± 0.009 g carotenoids/100 g, 0.76 ± 0.013 g chlorophyll a/100 g, and 0.42 ± 0.015 g chlorophyll b/100 g with a chlorophyll a/b ratio of 1.8 were detected. The main chemical elements found were S, Mg, and P. The cells of BR003 were elliptically curved at the ends and without appendages. Histochemical tests showed carbohydrates distributed in the cytoplasm and pyrenoids, some lipid droplets, and proteins. The cytoplasm is rich in vacuoles, rough endoplasmic reticulum, mitochondria, and chloroplasts. The nucleus has a predominance of decondensed chromatin, and the cell wall has three layers. Chloroplasts have many starch granules and may be associated with a spherical central pyrenoid. To the best of our knowledge, this was the first biochemical description combined with ultrastructural morphological characterization of the strain T. obliquus BR003, grown under standard conditions, to demonstrate specific characteristics of the species.
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Affiliation(s)
| | - Jimmy Soares
- Department of Agricultural Engineering, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | | | | | | | - Maria Clara Nunes
- Department of Veterinary Medicine, Universidade Federal de Viçosa, Viçosa, Brazil
| | - José Eduardo Serrão
- Department of General Biology, Universidade Federal de Viçosa, Viçosa, Brazil.
| | - Marcio Arêdes Martins
- Department of Agricultural Engineering, Universidade Federal de Viçosa, Viçosa, Brazil
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8
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Role of Microalgae in Global CO2 Sequestration: Physiological Mechanism, Recent Development, Challenges, and Future Prospective. SUSTAINABILITY 2021. [DOI: 10.3390/su132313061] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The rising concentration of global atmospheric carbon dioxide (CO2) has severely affected our planet’s homeostasis. Efforts are being made worldwide to curb carbon dioxide emissions, but there is still no strategy or technology available to date that is widely accepted. Two basic strategies are employed for reducing CO2 emissions, viz. (i) a decrease in fossil fuel use, and increased use of renewable energy sources; and (ii) carbon sequestration by various biological, chemical, or physical methods. This review has explored microalgae’s role in carbon sequestration, the physiological apparatus, with special emphasis on the carbon concentration mechanism (CCM). A CCM is a specialized mechanism of microalgae. In this process, a sub-cellular organelle known as pyrenoid, containing a high concentration of Ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco), helps in the fixation of CO2. One type of carbon concentration mechanism in Chlamydomonas reinhardtii and the association of pyrenoid tubules with thylakoids membrane is represented through a typical graphical model. Various environmental factors influencing carbon sequestration in microalgae and associated techno-economic challenges are analyzed critically.
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9
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Goel D, Sinha S. Naturally occurring protein nano compartments: basic structure, function, and genetic engineering. NANO EXPRESS 2021. [DOI: 10.1088/2632-959x/ac2c93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Turnšek J, Brunson JK, Viedma MDPM, Deerinck TJ, Horák A, Oborník M, Bielinski VA, Allen AE. Proximity proteomics in a marine diatom reveals a putative cell surface-to-chloroplast iron trafficking pathway. eLife 2021; 10:e52770. [PMID: 33591270 PMCID: PMC7972479 DOI: 10.7554/elife.52770] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/15/2021] [Indexed: 12/16/2022] Open
Abstract
Iron is a biochemically critical metal cofactor in enzymes involved in photosynthesis, cellular respiration, nitrate assimilation, nitrogen fixation, and reactive oxygen species defense. Marine microeukaryotes have evolved a phytotransferrin-based iron uptake system to cope with iron scarcity, a major factor limiting primary productivity in the global ocean. Diatom phytotransferrin is endocytosed; however, proteins downstream of this environmentally ubiquitous iron receptor are unknown. We applied engineered ascorbate peroxidase APEX2-based subcellular proteomics to catalog proximal proteins of phytotransferrin in the model marine diatom Phaeodactylum tricornutum. Proteins encoded by poorly characterized iron-sensitive genes were identified including three that are expressed from a chromosomal gene cluster. Two of them showed unambiguous colocalization with phytotransferrin adjacent to the chloroplast. Further phylogenetic, domain, and biochemical analyses suggest their involvement in intracellular iron processing. Proximity proteomics holds enormous potential to glean new insights into iron acquisition pathways and beyond in these evolutionarily, ecologically, and biotechnologically important microalgae.
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Affiliation(s)
- Jernej Turnšek
- Biological and Biomedical Sciences, The Graduate School of Arts and Sciences, Harvard UniversityCambridgeUnited States
- Department of Systems Biology, Harvard Medical SchoolBostonUnited States
- Wyss Institute for Biologically Inspired Engineering, Harvard UniversityBostonUnited States
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San DiegoLa JollaUnited States
- Center for Research in Biological Systems, University of California San DiegoLa JollaUnited States
- Microbial and Environmental Genomics, J. Craig Venter InstituteLa JollaUnited States
| | - John K Brunson
- Microbial and Environmental Genomics, J. Craig Venter InstituteLa JollaUnited States
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San DiegoLa JollaUnited States
| | | | - Thomas J Deerinck
- National Center for Microscopy and Imaging Research, University of California San DiegoLa JollaUnited States
| | - Aleš Horák
- Biology Centre CAS, Institute of ParasitologyČeské BudějoviceCzech Republic
- University of South Bohemia, Faculty of ScienceČeské BudějoviceCzech Republic
| | - Miroslav Oborník
- Biology Centre CAS, Institute of ParasitologyČeské BudějoviceCzech Republic
- University of South Bohemia, Faculty of ScienceČeské BudějoviceCzech Republic
| | - Vincent A Bielinski
- Synthetic Biology and Bioenergy, J. Craig Venter InstituteLa JollaUnited States
| | - Andrew Ellis Allen
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San DiegoLa JollaUnited States
- Microbial and Environmental Genomics, J. Craig Venter InstituteLa JollaUnited States
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Flamholz AI, Dugan E, Blikstad C, Gleizer S, Ben-Nissan R, Amram S, Antonovsky N, Ravishankar S, Noor E, Bar-Even A, Milo R, Savage DF. Functional reconstitution of a bacterial CO 2 concentrating mechanism in Escherichia coli. eLife 2020; 9:59882. [PMID: 33084575 PMCID: PMC7714395 DOI: 10.7554/elife.59882] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/20/2020] [Indexed: 12/19/2022] Open
Abstract
Many photosynthetic organisms employ a CO2 concentrating mechanism (CCM) to increase the rate of CO2 fixation via the Calvin cycle. CCMs catalyze ≈50% of global photosynthesis, yet it remains unclear which genes and proteins are required to produce this complex adaptation. We describe the construction of a functional CCM in a non-native host, achieved by expressing genes from an autotrophic bacterium in an Escherichia coli strain engineered to depend on rubisco carboxylation for growth. Expression of 20 CCM genes enabled E. coli to grow by fixing CO2 from ambient air into biomass, with growth in ambient air depending on the components of the CCM. Bacterial CCMs are therefore genetically compact and readily transplanted, rationalizing their presence in diverse bacteria. Reconstitution enabled genetic experiments refining our understanding of the CCM, thereby laying the groundwork for deeper study and engineering of the cell biology supporting CO2 assimilation in diverse organisms.
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Affiliation(s)
- Avi I Flamholz
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Eli Dugan
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Shmuel Gleizer
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Roee Ben-Nissan
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Shira Amram
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Niv Antonovsky
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Sumedha Ravishankar
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Elad Noor
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Arren Bar-Even
- Max Planck Institute of Molecular Plant PhysiologyPotsdamGermany
| | - Ron Milo
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
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