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Anabaena sp.PCC 7120

Divya T V, Pallavi Chandwadkar, Celin Acharya
Metallothioneins (MTs) are low molecular weight, sulfhydryl-containing, cysteine-rich, metal-binding proteins. Eukaryotes have multiple metallothionein genes; however, there is dearth of reports on prokaryotic metallothioneins. Bacterial MTs with SmtA from Synechococcus PCC 7942 as prototype have been studied in the context of cadmium detoxification. In this study, a smtA related ORF, namely nmtA, was identified in the heterocystous, nitrogen-fixing cyanobacterium, Anabaena PCC 7120. A recombinant N-terminal histidine-tagged Anabaena NmtA protein was overexpressed in Escherichia coli and purified...
March 30, 2018: Aquatic Toxicology
Alexandra A Popova, Ulla Rasmussen, Tatiana A Semashko, Vadim M Govorun, Olga A Koksharova
Various species of cyanobacteria, diatoms and dinoflagellates are capable of synthesizing the non-proteinogenic neurotoxic amino acid β-N-methylamino-L-alanine (BMAA), which is known to be a causative agent of human neurodegeneration. Similar to most cyanotoxins, the biological and ecological functions of BMAA in cyanobacteria are unknown. In this study, we show for the first time that BMAA, in micromolar amounts, inhibits the formation of heterocysts (specialized nitrogen-fixing cells) in heterocystous, diazotrophic cyanobacteria (Anabaena sp...
April 6, 2018: Environmental Microbiology Reports
Takahiro Teramoto, Chihiro Azai, Kazuki Terauchi, Masashi Yoshimura, Toshiaki Ohta
Soft X-ray microscopy (SXM) is a minimally invasive technique for single-cell high-resolution imaging, as well as the visualization of intracellular distributions of light elements such as carbon, nitrogen and oxygen. We used SXM to observe photosynthesis and nitrogen-fixation in the filamentous cyanobacterium Anabaena sp. PCC 7120, which can form heterocysts during nitrogen starvation. Statistical and spectroscopic analyses from soft X-ray microscopic images around the K-absorption edge of nitrogen revealed a significant difference in the carbon-to-nitrogen (C/N) ratio between vegetative cells and heterocysts...
March 26, 2018: Plant Physiology
Jitendra Kumar, Anuradha Patel, Sanjesh Tiwari, Santwana Tiwari, Prabhat Kumar Srivastava, Sheo Mohan Prasad
The current study was undertaken to elucidate the impact of the herbicide pretilachlor (3 µg ml-1 and 6 µg ml-1 ) on cyanobacteria, Nostoc muscorum ATCC 27893 and Anabaena sp. PCC 7120 under three levels of photoacclimatization (suboptimum, 25 µmol photon m-2 s-1 ; optimum, 75 µmol photon m-2 s-1 ; and supra-optimum, 225 µmol photon m-2 s-1 ) by analyzing certain physiological (biomass accumulation, photosynthesis, Chl a fluorescence and respiration) and biochemical parameters (photosynthetic pigments‒ chlorophyll a, carotenoids and phycocyanin; reactive oxygen species‒ O2 • ¯, H2 O2 , lipid peroxidation; antioxidant system‒ superoxide dismutase, peroxidise, catalase and glutathione-S-transferase)...
March 21, 2018: Ecotoxicology and Environmental Safety
David Bolton, Leonid S Brown, Vladimir Ladizhansky
Anabaena Sensory Rhodopsin (ASR) is a unique photochromic membrane-embedded photosensor which interacts with soluble transducer and is likely involved in a light-dependent gene regulation in the cyanobacterium Anabaena sp. PCC 7120. We report partial spectroscopic1 H,13 C and15 N assignments of perdeuterated and back-exchanged ASR reconstituted in lipids. The reported assignments are in general agreement with previously determined assignments of carbon and nitrogen resonances in fully protonated samples. Because the back-exchange was performed on ASR in a detergent-solubilized state, the location of detected residues reports on the solvent accessibility of ASR in detergent...
March 23, 2018: Biomolecular NMR Assignments
Jan Bornikoel, Julia Staiger, Johannes Madlung, Karl Forchhammer, Iris Maldener
Heterocyst-forming cyanobacteria are organized as multicellular filaments of tightly interacting, functionally specialized cells. N 2 -fixing heterocysts differentiate from vegetative cells under nitrogen limitation in a semi-regular pattern along the filament. Diazotrophic growth requires metabolite exchange between neighboring cells within the filament. This exchange occurs via cell-cell junction complexes that span the gap between the plasma membranes and thereby cross the septal peptidoglycan through an array of uniform nanopores formed by AmiC-type cell wall hydrolases...
February 13, 2018: Molecular Microbiology
Dmitry Shvarev, Iris Maldener
Two hundred genes or 3% of the known or putative protein-coding genes of the filamentous freshwater cyanobacterium Anabaena sp. PCC 7120 encode domains of ATP-binding cassette (ABC) transporters. Detailed characterization of some of these transporters (14 - 15 importers and 5 exporters) has revealed their crucial roles in the complex lifestyle of this multicellular photoautotroph, which is able to differentiate specialized cells for nitrogen fixation. This review summarizes the characteristics of the ABC transporters of Anabaena sp...
January 19, 2018: FEMS Microbiology Letters
Violeta C Sein-Echaluce, María Carmen Pallarés, Anabel Lostao, Inmaculada Yruela, Adrián Velázquez-Campoy, M Luisa Peleato, María F Fillat
FUR (Ferric uptake regulator) proteins are among the most important families of transcriptional regulators in prokaryotes, often behaving as global regulators. In the cyanobacterium Anabaena PCC 7120, FurB (Zur, Zinc uptake regulator) controls zinc and redox homeostasis through the repression of target genes in a zinc-dependent manner. In vitro , non-specific binding of FurB to DNA elicits protection against oxidative damage and avoids cleavage by deoxyribonuclease I. The present study provides, for the first time, evidence of the influence of redox environment in the interaction of FurB with regulatory zinc and its consequences in FurB-DNA-binding affinity...
January 5, 2018: Biochemical Journal
Mercedes Nieves-Morión, Enrique Flores
Cyanobacteria are generally capable of photoautotrophic growth and are widely distributed on Earth. The model filamentous, heterocyst-forming strain Anabaena sp. PCC 7120 has been long considered a strict photoautotroph but is now known to be able to assimilate fructose. We have previously described two components of ABC glucoside uptake transporters from Anabaena that are involved in uptake of the sucrose analog esculin: GlsC (a nucleotide-binding domain subunit [NBD]) and GlsP (a transmembrane component [TMD])...
November 21, 2017: Environmental Microbiology Reports
Shigeki Ehira, Takuto Takeuchi, Akiyoshi Higo
Cyanobacteria, which perform oxygenic photosynthesis, have drawn attention as hosts for the direct production of biofuels and commodity chemicals from CO2 and H2O using light energy. Although cyanobacteria capable of producing diverse chemicals have been generated by metabolic engineering, anaerobic non-photosynthetic culture conditions are often necessary for their production. In this study, we conducted cell type-specific metabolic engineering of the filamentous cyanobacterium Anabaena sp. PCC 7120, which forms a terminally differentiated cell called a heterocyst with a semi-regular spacing of 10-15 cells...
November 15, 2017: Applied Microbiology and Biotechnology
Akiyoshi Higo, Atsuko Isu, Yuki Fukaya, Shigeki Ehira, Toru Hisabori
Anabaena sp. PCC 7120 (A. 7120) is a heterocyst-forming multicellular cyanobacterium that performs nitrogen fixation. This cyanobacterium has been extensively studied as a model for multicellularity in prokaryotic cells. We have been interested in photosynthetic production of nitrogenous compounds using A. 7120. However, the lack of efficient gene repression tools has limited its usefulness. We originally developed an artificial endogenous gene repression method in this cyanobacterium using small antisense RNA (Higo A...
November 3, 2017: Plant & Cell Physiology
Félix Ramos-León, Vicente Mariscal, Natalia Battchikova, Eva-Mari Aro, Enrique Flores
Heterocyst-forming cyanobacteria grow as filaments that can be hundreds of cells long. Proteinaceous septal junctions provide cell-cell binding and communication functions in the filament. In Anabaena sp. strain PCC 7120, the SepJ protein is important for the formation of septal junctions. SepJ consists of integral membrane and extramembrane sections - the latter including linker and coiled-coil domains. SepJ (predicted MW, 81.3 kDa) solubilized from Anabaena membranes was found in complexes of about 296-334 kDa, suggesting that SepJ forms multimeric complexes...
October 2017: FEBS Open Bio
Jan Bornikoel, Alejandro Carrión, Qing Fan, Enrique Flores, Karl Forchhammer, Vicente Mariscal, Conrad W Mullineaux, Rebeca Perez, Nadine Silber, C Peter Wolk, Iris Maldener
Filamentous cyanobacteria have developed a strategy to perform incompatible processes in one filament by differentiating specialized cell types, N2-fixing heterocysts and CO2-fixing, photosynthetic, vegetative cells. These bacteria can be considered true multicellular organisms with cells exchanging metabolites and signaling molecules via septal junctions, involving the SepJ and FraCD proteins. Previously, it was shown that the cell wall lytic N-acetylmuramyl-L-alanine amidase, AmiC2, is essential for cell-cell communication in Nostoc punctiforme...
2017: Frontiers in Cellular and Infection Microbiology
Steeve Lima, Paulo Oliveira, Paula Tamagnini
Cyanobacteria are photosynthetic prokaryotes, capable of sustaining their growth by converting sunlight into chemical energy by fixing CO2 into organic matter. The cyanobacterium Anabaena sp. PCC 7120 is also capable of fixing atmospheric nitrogen, a metabolic process that occurs in specialized cells, the heterocysts. During the process of heterocyst differentiation, drastic morphological changes occur to prepare the future differentiated cell to accommodate the nitrogen fixation metabolism, which is a highly O2-sensitive process...
August 15, 2017: FEMS Microbiology Letters
Laura A Antonaru, Dennis J Nürnberg
Cell differentiation is one of the marks of multicellular organisms. Terminally specialised nitrogen-fixing cells, termed heterocysts, evolved in filamentous cyanobacteria more than 2 Gya. The development of their spacing pattern has been thoroughly investigated in model organisms such as Anabaena sp. PCC 7120. This paper focuses on the more complex, branching cyanobacterium Mastigocladus laminosus (Stigonematales). Contrary to what has been previously published, a heterocyst spacing pattern is present in M...
August 15, 2017: FEMS Microbiology Letters
Manish Singh Kaushik, Meenakshi Srivastava, Anumeha Singh, Arun Kumar Mishra
Iron deficiency ends up into several unavoidable consequences including damaging oxidative stress in cyanobacteria. NtcA is a global nitrogen regulator controls wide range of metabolisms in addition to regulation of nitrogen metabolism. In present communication, NtcA based regulation of iron homeostasis, ROS production and cellular phenotype under iron deficiency in Anabaena 7120 has been investigated. NtcA regulates the concentration dependent iron uptake by controlling the expression of furA gene. NtcA also regulated pigment synthesis and phenotypic alterations in Anabaena 7120...
August 2017: World Journal of Microbiology & Biotechnology
Savita Singh, Ekta Verma, Balkrishna Tiwari, Niveshika, Arun Kumar Mishra
Calcium being a signaling molecule and mediator of cell response, we examined the modulation in fatty acid and hydrocarbon profiles of wild type cyanobacterium Anabaena sp. PCC 7120 and its ntcA mutant under the influence of different calcium chloride concentrations (0-10 mM). Dynamic modifications in fatty acid and hydrocarbon profile were evident through GC-FID analysis of extracted lipids. In the wild type, increase in CaCl2 (10 mM) resulted in unsaturation of fatty acids (observed in terms of high MUFA/PUFA ratio) while hydrocarbon production was distinctly high in the mutant strain compared to wild type at all tested concentrations...
February 2017: Journal of Basic Microbiology
Zhenggao Zheng, Amin Omairi-Nasser, Xiying Li, Chunxia Dong, Yan Lin, Robert Haselkorn, Jindong Zhao
Channels that cross cell walls and connect the cytoplasm of neighboring cells in multicellular cyanobacteria are pivotal for intercellular communication. We find that the product of the gene all1140 of the filamentous cyanobacterium Anabaena sp. PCC 7120 is required for proper channel formation. All1140 encodes an amidase that hydrolyses purified peptidoglycans. An All1140-GFP fusion protein is located at the Z-ring in the periplasmic space during most of the cell cycle. An all1140-null mutant (M40) was unable to grow diazotrophically, and no mature heterocysts were observed in the absence of combined nitrogen...
February 21, 2017: Proceedings of the National Academy of Sciences of the United States of America
Masahiro Takeya, Masami Yokota Hirai, Takashi Osanai
Phosphoenolpyruvate carboxylase (PEPC) is an important enzyme for CO2 fixation and primary metabolism in photosynthetic organisms including cyanobacteria. The kinetics and allosteric regulation of PEPCs have been studied in many organisms, but the biochemical properties of PEPC in the unicellular, non-nitrogen-fixing cyanobacterium Synechocystis sp. PCC 6803 have not been clarified. In this study, biochemical analysis revealed that the optimum pH and temperature of Synechocystis 6803 PEPC proteins were 7.3 and 30 °C, respectively...
January 24, 2017: Scientific Reports
Mercedes Nieves-Morión, Sigal Lechno-Yossef, Rocío López-Igual, José E Frías, Vicente Mariscal, Dennis J Nürnberg, Conrad W Mullineaux, C Peter Wolk, Enrique Flores
When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO2 through oxygenic photosynthesis and heterocysts that are specialized in N2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells...
April 1, 2017: Journal of Bacteriology
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