A5072068051- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- Photoreceptor and optogenetics research
- Spectroscopy and Quantum Chemical Studies
- Biocrusts and Microbial Ecology
- Light effects on plants
- Protist diversity and phylogeny
- Mitochondrial Function and Pathology
- Microbial Community Ecology and Physiology
- Plant Stress Responses and Tolerance
- Marine and coastal ecosystems
- ATP Synthase and ATPases Research
- Bacterial Genetics and Biotechnology
- Bacteriophages and microbial interactions
- Advanced Fluorescence Microscopy Techniques
- Escherichia coli research studies
- Lipid Membrane Structure and Behavior
- RNA and protein synthesis mechanisms
- Antioxidant Activity and Oxidative Stress
- bioluminescence and chemiluminescence research
- Cell Image Analysis Techniques
- Protein Structure and Dynamics
- Aquatic Ecosystems and Phytoplankton Dynamics
- Genomics and Phylogenetic Studies
- Cancer Research and Treatments
Queen Mary University of London
2015-2024
Universidad de Londres
2024
Transnational Press London
2019
University of Freiburg
2014-2016
Universities UK
2014
University College London
1998-2012
Institute of Structural and Molecular Biology
2012
University of Oxford
2012
Imperial College London
2012
University of Warwick
2003-2008
Abstract Plants must regulate their use of absorbed light energy on a minute-by-minute basis to maximize the efficiency photosynthesis and protect photosystem II (PSII) reaction centers from photooxidative damage. The regulation harvesting involves photoprotective dissipation excess in light-harvesting antenna complexes (LHCs) as heat. Here, we report an investigation into structural intact spinach (Spinacia oleracea) chloroplasts using freeze-fracture electron microscopy, combined with...
Using a var2-2 mutant ofArabidopsis thaliana, which lacks homologue of the zinc-metalloprotease, FtsH, we demonstrate that this protease is required for efficient turnover D1 polypeptide photosystem II and protection against photoinhibition in vivo. We show leaves are much more susceptible to light-induced than wild-type leaves. Furthermore, rate untreated equivalent leaves, have been treated with lincomycin, an inhibitor repair cycle at level synthesis. This contrast slower due cycle. The...
Abstract When plants, algae, and cyanobacteria are exposed to excessive light, especially in combination with other environmental stress conditions such as extreme temperatures, their photosynthetic performance declines. A major cause of this photoinhibition is the light-induced irreversible photodamage photosystem II (PSII) complex responsible for oxygen evolution. repair cycle operates selectively replace a damaged D1 subunit within PSII newly synthesized copy followed by light-driven...
Surprisingly little is known about the physical environment inside a prokaryotic cell. Knowledge of rates at which proteins and other cell components can diffuse crucial for understanding as system. There have been numerous measurements diffusion coefficients in eukaryotic cells by using fluorescence recovery after photobleaching (FRAP) related techniques. Much less information available cells, differ from number significant respects. We used FRAP to observe green fluorescent protein (GFP)...
We characterized a set of Arabidopsis mutants deficient in specific light-harvesting proteins, using freeze-fracture electron microscopy to probe the organization complexes membrane and confocal fluorescence recovery after photobleaching dynamics thylakoid membranes within intact chloroplasts. The same methods were used characterize lacking or over-expressing PsbS, protein related that appears play role regulation photosynthetic light harvesting. found changes complement PsbS have striking...
Abstract The light reactions of oxygenic photosynthesis almost invariably take place in the thylakoid membranes, a highly specialized internal membrane system located stroma chloroplasts and cytoplasm cyanobacteria. only known exception is primordial cyanobacterium Gloeobacter violaceus, which evolved before appearance thylakoids harbors photosynthetic complexes plasma membrane. Thus, studies on G. violaceus not shed evolutionary origin functional advantages membranes but also might include...
Chemiosmotic energy coupling through oxidative phosphorylation (OXPHOS) is crucial to life, requiring coordinated enzymes whose membrane organization and dynamics are poorly understood. We quantitatively explore localization, stoichiometry, of key OXPHOS complexes, functionally fluorescent protein-tagged, in Escherichia coli using low-angle fluorescence superresolution microscopy, applying single-molecule analysis novel nanoscale co-localization measurements. Mobile 100–200 nm domains...
Bacterial phototaxis was first recognized over a century ago, but the method by which such small cells can sense direction of illumination has remained puzzling. The unicellular cyanobacterium Synechocystis sp. PCC 6803 moves with Type IV pili and measures light intensity color range photoreceptors. Here, we show that individual do not respond to spatiotemporal gradient in intensity, rather they directly accurately position source. We directional sensing is possible because act as spherical...
In cyanobacteria, respiratory electron transport takes place in close proximity to photosynthetic transport, because the complexes required for both processes are located within thylakoid membranes. The balance of routes is crucial cell physiology, yet factors that control predominance particular pathways poorly understood. Here we use a combination tagging with green fluorescent protein and confocal fluorescence microscopy live cells cyanobacterium Synechococcus elongatus PCC 7942...
ABSTRACT Many filamentous cyanobacteria produce specialized nitrogen-fixing cells called heterocysts, which are located at semiregular intervals along the filament with about 10 to 20 photosynthetic vegetative in between. Nitrogen fixation these complex multicellular bacteria depends on metabolite exchange between two cell types, heterocysts supplying combined-nitrogen compounds but dependent for photosynthetically produced carbon compounds. Here, we used a fluorescent tracer probe...
The structural dynamics and flexibility of cell membranes play fundamental roles in the functions cells, i.e., signaling, energy transduction, physiological adaptation. cyanobacterial thylakoid membrane represents a model that can conduct both oxygenic photosynthesis respiration simultaneously. In this study, we conducted direct visualization global organization mobility photosynthetic complexes from cyanobacterium, Synechococcus elongatus PCC 7942, using high-resolution atomic force,...
How thylakoid membranes are generated to form a metabolically active membrane network and how orchestrate the insertion localization of protein complexes for efficient electron flux remain elusive. Here, we develop method modulate biogenesis in rod-shaped cyanobacterium Synechococcus elongatus PCC 7942 by modulating light intensity during cell growth, probe spatial-temporal stepwise process cells. Our results reveal that plasma regularly arranged concentric layers have no physical...
Abstract Photosynthesis—the conversion of energy from sunlight into chemical energy—is essential for life on Earth. Yet there is much we do not understand about photosynthetic a fundamental level: how it evolved and the extent its diversity, dynamics, all components connections involved in regulation. In this commentary, researchers working aspects photosynthesis including light-dependent reactions, photorespiration, C4 metabolism pose discuss what they view as most compelling open questions...
The cyanobacterium Synechocystis sp. PCC 6803 contains four members of the FtsH protease family. One these, (slr0228), has been implicated recently in repair photodamaged photosystem II (PSII) complexes. We have demonstrated here, using a combination blue native PAGE, radiolabeling, and immunoblotting, that (slr0228) is required for selective replacement D1 reaction center subunit both wild type PSII complexes subcomplexes lacking chlorophyll a-binding CP43. To test whether more general role...
Photosynthetic organisms respond to changes in ambient light by modulating the size and composition of their light-harvesting complexes, which case green alga Chlamydomonas reinhardtii consists >15 members a large extended family chlorophyll binding subunits. How expression is coordinated unclear. Here, we describe analysis an insertion mutant, state transitions mutant3 (stm3), show has increased levels LHCBM subunits associated with antenna photosystem II. The mutated nuclear gene stm3...
A variant of fluorescence recovery after photobleaching allows us to observe the diffusion photosynthetic complexes in cyanobacterial thylakoid membranes vivo. The unicellular cyanobacterium Synechococcus sp. PCC7942 is a wonderful model organism for photobleaching, because it has favorable membrane geometry and well characterized transformable. In 7942 (as other cyanobacteria) we find that photosystem II immobile, but phycobilisomes diffuse rapidly on surface. coefficient 3 x 10(-10) cm(2)...