Did you mean: chlamydomonas
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Cell Dec 2022The TOC and TIC complexes are essential translocons that facilitate the import of the nuclear genome-encoded preproteins across the two envelope membranes of...
The TOC and TIC complexes are essential translocons that facilitate the import of the nuclear genome-encoded preproteins across the two envelope membranes of chloroplast, but their exact molecular identities and assembly remain unclear. Here, we report a cryoelectron microscopy structure of TOC-TIC supercomplex from Chlamydomonas, containing a total of 14 identified components. The preprotein-conducting pore of TOC is a hybrid β-barrel co-assembled by Toc120 and Toc75, while the potential translocation path of TIC is formed by transmembrane helices from Tic20 and YlmG, rather than a classic model of Tic110. A rigid intermembrane space (IMS) scaffold bridges two chloroplast membranes, and a large hydrophilic cleft on the IMS scaffold connects TOC and TIC, forming a pathway for preprotein translocation. Our study provides structural insights into the TOC-TIC supercomplex composition, assembly, and preprotein translocation mechanism, and lays a foundation to interpret the evolutionary conservation and diversity of this fundamental translocon machinery.
Topics: Chloroplasts; Cryoelectron Microscopy; Intracellular Membranes; Protein Transport; Chlamydomonas; Multiprotein Complexes; Algal Proteins
PubMed: 36413996
DOI: 10.1016/j.cell.2022.10.030 -
Philosophical Transactions of the Royal... Feb 2020The generation of ciliary waveforms requires the spatial and temporal regulation of dyneins. This review catalogues many of the asymmetric structures and proteins in the... (Review)
Review
The generation of ciliary waveforms requires the spatial and temporal regulation of dyneins. This review catalogues many of the asymmetric structures and proteins in the cilia of , a unicellular alga with two cilia that are used for motility in liquid medium. These asymmetries, which have been identified through mutant analysis, cryo-EM tomography and proteomics, provide a wealth of information to use for modelling how waveforms are generated and propagated. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.
Topics: Chlamydomonas; Cilia; Electron Microscope Tomography; Proteomics
PubMed: 31884924
DOI: 10.1098/rstb.2019.0153 -
The Plant Journal : For Cell and... May 2015The position of Chlamydomonas within the eukaryotic phylogeny makes it a unique model in at least two important ways: as a representative of the critically important,... (Review)
Review
The position of Chlamydomonas within the eukaryotic phylogeny makes it a unique model in at least two important ways: as a representative of the critically important, early-diverging lineage leading to plants; and as a microbe retaining important features of the last eukaryotic common ancestor (LECA) that has been lost in the highly studied yeast lineages. Its cell biology has been studied for many decades and it has well-developed experimental genetic tools, both classical (Mendelian) and molecular. Unlike land plants, it is a haploid with very few gene duplicates, making it ideal for loss-of-function genetic studies. The Chlamydomonas cell cycle has a striking temporal and functional separation between cell growth and rapid cell division, probably connected to the interplay between diurnal cycles that drive photosynthetic cell growth and the cell division cycle; it also exhibits a highly choreographed interaction between the cell cycle and its centriole-basal body-flagellar cycle. Here, we review the current status of studies of the Chlamydomonas cell cycle. We begin with an overview of cell-cycle control in the well-studied yeast and animal systems, which has yielded a canonical, well-supported model. We discuss briefly what is known about similarities and differences in plant cell-cycle control, compared with this model. We next review the cytology and cell biology of the multiple-fission cell cycle of Chlamydomonas. Lastly, we review recent genetic approaches and insights into Chlamydomonas cell-cycle regulation that have been enabled by a new generation of genomics-based tools.
Topics: Animals; Cell Cycle; Chlamydomonas; Cytokinesis; Gene Expression Regulation; Mutation; Phylogeny; Plants; Viridiplantae
PubMed: 25690512
DOI: 10.1111/tpj.12795 -
Cells Sep 2019Microalgae have emerged as a promising platform for production of carbon- and energy- rich molecules, notably starch and oil. Establishing an economically viable algal... (Review)
Review
Microalgae have emerged as a promising platform for production of carbon- and energy- rich molecules, notably starch and oil. Establishing an economically viable algal biotechnology sector requires a holistic understanding of algal photosynthesis, physiology, cell cycle and metabolism. Starch/oil productivity is a combined effect of their cellular content and cell division activities. Cell growth, starch and fatty acid synthesis all require carbon building blocks and a source of energy in the form of ATP and NADPH, but with a different requirement in ATP/NADPH ratio. Thus, several cellular mechanisms have been developed by microalgae to balance ATP and NADPH supply which are essentially produced by photosynthesis. Major energy management mechanisms include ATP production by the chloroplast-based cyclic electron flow and NADPH removal by water-water cycles. Furthermore, energetic coupling between chloroplast and other cellular compartments, mitochondria and peroxisome, is increasingly recognized as an important process involved in the chloroplast redox poise. Emerging literature suggests that alterations of energy management pathways affect not only cell fitness and survival, but also influence biomass content and composition. These emerging discoveries are important steps towards diverting algal photosynthetic energy to useful products for biotechnological applications.
Topics: Adenosine Triphosphate; Carbon; Chlamydomonas; Electron Transport; NADP; Photosynthesis; Starch
PubMed: 31561610
DOI: 10.3390/cells8101154 -
ELife Nov 2018In Chlamydomonas the different stages of the Calvin-Benson cycle take place in separate locations within the chloroplast.
In Chlamydomonas the different stages of the Calvin-Benson cycle take place in separate locations within the chloroplast.
Topics: Chlamydomonas; Chlamydomonas reinhardtii; Chloroplasts; Photosynthesis; Ribulose-Bisphosphate Carboxylase
PubMed: 30426925
DOI: 10.7554/eLife.42507 -
The Plant Journal : For Cell and... May 2015Heat waves occurring at increased frequency as a consequence of global warming jeopardize crop yield safety. One way to encounter this problem is to genetically engineer... (Review)
Review
Heat waves occurring at increased frequency as a consequence of global warming jeopardize crop yield safety. One way to encounter this problem is to genetically engineer crop plants toward increased thermotolerance. To identify entry points for genetic engineering, a thorough understanding of how plant cells perceive heat stress and respond to it is required. Using the unicellular green alga Chlamydomonas reinhardtii as a model system to study the fundamental mechanisms of the plant heat stress response has several advantages. Most prominent among them is the suitability of Chlamydomonas for studying stress responses system-wide and in a time-resolved manner under controlled conditions. Here we review current knowledge on how heat is sensed and signaled to trigger temporally and functionally grouped sub-responses termed response elements to prevent damage and to maintain cellular homeostasis in plant cells.
Topics: Calcium; Cell Cycle Checkpoints; Cell Membrane; Chlamydomonas; Chlamydomonas reinhardtii; Heat-Shock Response; Plant Cells; Plant Proteins; Protein Kinases; Signal Transduction
PubMed: 25754362
DOI: 10.1111/tpj.12816 -
The Plant Journal : For Cell and... May 2015Developing renewable energy sources is critical to maintaining the economic growth of the planet while protecting the environment. First generation biofuels focused on... (Review)
Review
Developing renewable energy sources is critical to maintaining the economic growth of the planet while protecting the environment. First generation biofuels focused on food crops like corn and sugarcane for ethanol production, and soybean and palm for biodiesel production. Second generation biofuels based on cellulosic ethanol produced from terrestrial plants, has received extensive funding and recently pilot facilities have been commissioned, but to date output of fuels from these sources has fallen well short of what is needed. Recent research and pilot demonstrations have highlighted the potential of algae as one of the most promising sources of sustainable liquid transportation fuels. Algae have also been established as unique biofactories for industrial, therapeutic, and nutraceutical co-products. Chlamydomonas reinhardtii's long established role in the field of basic research in green algae has paved the way for understanding algal metabolism and developing genetic engineering protocols. These tools are now being utilized in C. reinhardtii and in other algal species for the development of strains to maximize biofuels and bio-products yields from the lab to the field.
Topics: Biofuels; Biotechnology; Chlamydomonas; Chlamydomonas reinhardtii; Chloroplasts; Genetic Engineering; High-Throughput Screening Assays; Homologous Recombination; Hydrogen; Microalgae
PubMed: 25641390
DOI: 10.1111/tpj.12780 -
International Journal of Molecular... Dec 2021Microalgae are photosynthetic unicellular organisms that can be found in very different environments, both terrestrial and marine, including extreme environments such as...
Microalgae are photosynthetic unicellular organisms that can be found in very different environments, both terrestrial and marine, including extreme environments such as cold, hot and high/low salinity [...].
Topics: Biomass; Chlamydomonas; Microalgae; Photosynthesis
PubMed: 34948247
DOI: 10.3390/ijms222413450 -
ELife Nov 2018In the mid-20th century, the unicellular and genetically tractable green alga was first developed as a model organism to elucidate fundamental cellular processes such... (Review)
Review
In the mid-20th century, the unicellular and genetically tractable green alga was first developed as a model organism to elucidate fundamental cellular processes such as photosynthesis, light perception and the structure, function and biogenesis of cilia. Various studies of have profoundly advanced plant and cell biology, and have also impacted algal biotechnology and our understanding of human disease. However, the 'real' life of in the natural environment has largely been neglected. To extend our understanding of the biology of , it will be rewarding to explore its behavior in its natural habitats, learning more about its abundance and life cycle, its genetic and physiological diversity, and its biotic and abiotic interactions.
Topics: Chlamydomonas reinhardtii; Ecosystem; Genomics; Phylogeography
PubMed: 30382941
DOI: 10.7554/eLife.39233 -
The Plant Journal : For Cell and... May 2015
Topics: Biofuels; Chlamydomonas; Photosynthesis; Research
PubMed: 25906814
DOI: 10.1111/tpj.12831