A5030507742- Photosynthetic Processes and Mechanisms
- Algal biology and biofuel production
- Lipid metabolism and biosynthesis
- Mitochondrial Function and Pathology
- Photoreceptor and optogenetics research
- Antioxidant Activity and Oxidative Stress
- Light effects on plants
- Biocrusts and Microbial Ecology
- Lipid Membrane Structure and Behavior
- Metabolomics and Mass Spectrometry Studies
- ATP Synthase and ATPases Research
- Plant biochemistry and biosynthesis
- Spectroscopy and Quantum Chemical Studies
- Plant Stress Responses and Tolerance
- Porphyrin and Phthalocyanine Chemistry
- Synthesis of β-Lactam Compounds
- Soft tissue tumors and treatment
- Menstrual Health and Disorders
- Ion channel regulation and function
- Edible Oils Quality and Analysis
- Cholesterol and Lipid Metabolism
- Liver physiology and pathology
- Cancer Genomics and Diagnostics
- Marine and coastal plant biology
- Physical Education and Training Studies
Hungarian School Sport Federation
2022
Hungarian Academy of Sciences
2008-2019
HUN-REN Szegedi Biológiai Kutatóközpont
2003-2019
Institute of Plant Biology
2005-2019
National Institute for Basic Biology
1991-2006
Moffitt Cancer Center
2006
University of Pennsylvania
2006
National Institute of Neurological Disorders and Stroke
2005
Jagiellonian University
2004
Kyushu University
1998-2003
Liver fibrosis, the response to chronic liver injury, results from activation of mesenchymal cells fibrogenic myofibroblasts. We have recently shown that two key myofibroblast precursor populations, hepatic stellate and portal fibroblasts, undergo in culture increasing substrate stiffness. therefore hypothesized alterations stiffness precede fibrosis vivo as well. To test this hypothesis, we induced rats by twice weekly injections carbon tetrachloride (CCl 4 ) then killed animals at various...
Using tobacco plants that had been transformed with the cDNA for glycerol-3-phosphate acyltransferase, we have demonstrated chilling tolerance is affected by levels of unsaturated membrane lipids. In present study, examined effects transformation acyltransferase from squash on unsaturation fatty acids in thylakoid lipids and response photosynthesis to various temperatures. Of four major lipid classes isolated membranes, phosphatidylglycerol showed most conspicuous decrease level plants. The...
In a previous study of mutants in fatty-acid desaturation Synechocystis PCC6803, it was demonstrated that the photoinhibition photosynthesis at low temperature vivo is tolerated by cells as result unsaturation glycerolipids thylakoid membranes. Since extent depends on balance between photoinduced inactivation and recovery from photoinhibited state, an examination made effects membrane lipids these processes. It appears does not affect process but accelerates and, moreover, apparent increase...
The contribution of the unsaturation membrane lipids to ability photosynthetic machinery tolerate temperature stress was studied in a transgenic cyanobacterium. Anacystis nidulans R2-SPc transformed with desA gene, which encodes Delta12-desaturase that desaturates fatty acids Synechocystis PCC6803. transformant acquired introduce second double bond into palmitoleic and oleic acids. transformation enhanced tolerance chilling but it had no detectable effect on heat stress. itself did not have...
Phosphatidylglycerol (PG), a ubiquitous constituent of thylakoid membranes chloroplasts and cyanobacteria, is demonstrated to be essential for the functionality plastoquinone electron acceptor QB in photosystem II reaction center oxygenic photosynthesis. Growth pgsA mutant cells Synechocystis sp. PCC6803 that are defective phosphatidylglycerolphosphate synthase incapable synthesizing PG, medium without resulted 90% decrease PG content 50% loss photosynthetic oxygen-evolving activity as...
Abstract Phosphatidylglycerol (PG) is a ubiquitous component of thylakoid membranes. Experiments with the pgsA mutant cyanobacterium Synechocystis sp. PCC6803 defective in biosynthesis PG have demonstrated an indispensable role photosynthesis. In present study, we investigated light susceptibility regard to maintenance photosynthetic machinery. Growth cells without increased and resulted severe photoinhibition photosynthesis upon high-light treatment, whereas growth presence was protected...
Effect of the unsaturation fatty acids in glycerolipids thylakoid membranes on low-temperature photoinhibition photosynthesis was studied by mutation and transformation cyanobacterium Synechocystis PCC6803. When grown at 34 degrees C, wild type contained mono-, di-, triunsaturated lipids; a mutant, designated Fad6, mono- diunsaturated transformant with disrupted gene for desaturation Fad6/desA::Kmr, only monounsaturated lipids. Fad6/desA::Kmr most susceptible among these strains to...
Abstract Our earlier studies with the pgsA mutant of Synechocystis PCC6803 demonstrated important role phosphatidylglycerol (PG) in PSII dimer formation and electron transport between primary secondary electron-accepting plastoquinones PSII. Using a long-term depletion PG from cells, we could induce decrease not only but also PSI activity. Simultaneously activity, dramatic structural changes complex were detected. A 21-d resulted degradation trimers concomitant accumulation monomer PSI. The...
In cyanobacterial cells, fatty acid desaturation is one of the crucial steps in acclimation processes to low-temperature conditions. The expression all four acyl lipid desaturase genes Synechocystis PCC 6803 was studied as a function temperature and separately light. We used cells grown at 25°C light-activated heterotrophic growth these production α-linolenic 18:4 acids negligible synthesis γ-linolenic remarkably suppressed compared with those photoautotrophically. light presence glucose...
Strong light leads to damage photosynthetic machinery, particularly at low temperatures, and the main site of is D1 protein photosystem II (PSII) complex. Here we describe that transformation Synechococcus sp. PCC 7942 with desA gene for a [delta]12 desaturase increased unsaturation membrane lipids enhanced tolerance strong light. To our knowledge, this first report successful genetic enhancement Analysis light-induced inactivation subsequent recovery activity PSII complex revealed process...
The cyanobacterium Synechococcus sp. strain PCC 7942 was transformed with the codA gene for choline oxidase from Arthrobacter globiformis under control of a constitutive promoter. This transformation allowed cyanobacterial cells to accumulate glycine betaine at 60 80 mM in cytoplasm. could grow 20 degrees C, temperature which growth markedly suppressed. Photosynthesis C more tolerant light than that cells. caused by enhanced ability photosynthetic machinery recover low-temperature...
The metal ion-induced inhibition of tetrapyrrole biosynthesis was studied in the cyanobacterium Anacystis nidulans . accumulation protoporphyrin and Mg due to effect Co 2+ Mn treatment, respectively, pointed two different sites inhibition.
In the thylakoid membranes of mesophilic cyanobacterium Synechocystis PCC6803, PSI reaction centers (RCs) are organized as monomers and trimers. PsaL, a 16 kDa hydrophobic protein, subunit RC, was previously identified crucial for formation this work, physiological effects accompanied by oligomerization were studied using PsaL-deficient mutant (Δ psaL ), not able to form trimers, grown at various temperatures. We demonstrate that in wild-type , monomer trimer ratio depends on growth...
The negatively charged lipid phosphatidylglycerol (PG) constitutes up to 10% of total lipids in photosynthetic membranes, and its deprivation cyanobacteria is accompanied by chlorophyll (Chl) depletion. Indeed, radioactive labeling the PG-depleted ƊpgsA mutant Synechocystis sp. strain PCC 6803, which not able synthesize PG, proved inhibition Chl biosynthesis caused restriction on formation 5-aminolevulinic acid protochlorophyllide. Although accumulated chlorophyllide, last precursor, we...
The effects of the growth temperature on lipids and carotenoids a filamentous cyanobacterium, Cylindrospermopsis raciborskii, were studied., relative amounts polyunsaturated glycerolipids myxoxanthophylls in thylakoid membranes increased markedly when this cyanobacterium was grown at 25 degrees C instead 35 C. Fourier transform infrared spectroscopy used to analyze low-temperature-induced structural alterations membranes. Despite higher amount unsaturated there, conventional analysis...
The desA gene of the cyanobacterium, Synechocystis PCC6803, is responsible for desaturation fatty acids at Δ12 position [Wada et al. (1990) Nature 347: 200]. A disrupted gene, which was interrupted by kanamycin-resistance cartridge, constructed to allow manipulation extent in membrane lipids PCC6803. Wild-type cells and those a mutant, Fad6, defective Δ6 C acids, were transformed with this gene. resultant transformant wild type lacked trienoic contained very reduced level dienoic Fad6 only...
Phosphatidylglycerol (PG) depletion suppressed the oxygen-evolving activity of Synechocystis PCC6803 pgsA mutant cells. Shortage PG led to decreased photosynthetic activity, which, similar effect high light exposure, is likely generate production reactive oxygen species (ROS) or free radicals. Protection PG-depleted cells against light-induced damage increased echinenone and myxoxanthophyll content The carotenoid was localized in a soluble fraction as well isolated thylakoid cytoplasmic...