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Anabaena sp.PCC 7120

Marco Agostoni, Alshaé R Logan-Jackson, Emily R Heinz, Geoffrey B Severin, Eric L Bruger, Christopher M Waters, Beronda L Montgomery
Second messengers are intracellular molecules regulated by external stimuli known as first messengers that are used for rapid organismal responses to dynamic environmental changes. Cyclic di-AMP (c-di-AMP) is a relatively newly discovered second messenger implicated in cell wall homeostasis in many pathogenic bacteria. C-di-AMP is synthesized from ATP by diadenylyl cyclases (DAC) and degraded by specific c-di-AMP phosphodiesterases (PDE). C-di-AMP DACs and PDEs are present in all sequenced cyanobacteria, suggesting roles for c-di-AMP in the physiology and/or development of these organisms...
2018: Frontiers in Microbiology
Orion S Rivers, Silvia Beurmann, Allexa Dow, Loralyn M Cozy, Patrick Videau
Multicellular organisms must carefully regulate the timing, number, and location of specialized cellular development. In the filamentous cyanobacterium Anabaena sp. strain PCC 7120, nitrogen-fixing heterocysts are interspersed between vegetative cells in a periodic pattern to achieve optimal exchange of bioavailable nitrogen and reduced carbon. The spacing between heterocysts is regulated by the activity of two developmental inhibitors: PatS and HetN. PatS functions to create a de novo pattern from a homogenous field of undifferentiated cells, while HetN maintains the pattern throughout subsequent growth...
May 21, 2018: Journal of Bacteriology
Francesca Di Patti, Laura Lavacchi, Rinat Arbel-Goren, Leora Schein-Lubomirsky, Duccio Fanelli, Joel Stavans
Under nitrogen deprivation, the one-dimensional cyanobacterial organism Anabaena sp. PCC 7120 develops patterns of single, nitrogen-fixing cells separated by nearly regular intervals of photosynthetic vegetative cells. We study a minimal, stochastic model of developmental patterns in Anabaena that includes a nondiffusing activator, two diffusing inhibitor morphogens, demographic fluctuations in the number of morphogen molecules, and filament growth. By tracking developing filaments, we provide experimental evidence for different spatiotemporal roles of the two inhibitors during pattern maintenance and for small molecular copy numbers, justifying a stochastic approach...
May 4, 2018: PLoS Biology
Yali Wang, Yuan Gao, Chao Li, Hong Gao, Cheng-Cai Zhang, Xudong Xu
Anabaena sp. strain PCC 7120 is a model strain for molecular studies of cell differentiation and patterning in heterocyst-forming cyanobacteria. Subtle differences in heterocyst development have been noticed in different laboratories working on the same organism. In this study, 360 mutations, including single nucleotide polymorphisms (SNPs), small insertion/deletions (indels; 1 to 3 bp), fragment deletions, and transpositions, were identified in the genomes of three substrains. Heterogeneous/heterozygous bases were also identified due to the polyploidy nature of the genome and the multicellular morphology but could be completely segregated when plated after filament fragmentation by sonication...
July 1, 2018: Journal of Bacteriology
Patrick Videau, Orion S Rivers, Sasa K Tom, Reid T Oshiro, Blake Ushijima, Vaille A Swenson, Benjamin Philmus, Michael O Gaylor, Loralyn M Cozy
Multicellular development requires the careful orchestration of gene expression to correctly create and position specialized cells. In the filamentous cyanobacterium Anabaena sp. strain PCC 7120, nitrogen-fixing heterocysts are differentiated from vegetative cells in a reproducibly periodic and physiologically relevant pattern. While many genetic factors required for heterocyst development have been identified, the role of HetZ has remained unclear. Here, we present evidence to clarify the requirement of hetZ for heterocyst production and support a model where HetZ functions in the patterning stage of differentiation...
April 20, 2018: Molecular Microbiology
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...
June 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 SXM 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...
May 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)...
July 30, 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 spectroscopic 1 H, 13 C and 15 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...
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. N2 -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...
April 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...
February 1, 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 H2 O 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...
February 2018: 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...
January 1, 2018: 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
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