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Patrick M Suess, Yu Tang, Richard H Gomer
Five or more orthophosphates bound together by high energy phospho-anhydride bonds are highly ubiquitous inorganic molecules called polyphosphate. Polyphosphate acts as a signaling molecule eliciting a number of responses in eukaryotic cells, but the mechanisms mediating these effects are poorly understood. Proliferating Dictyostelium discoideum cells accumulate extracellular polyphosphate. At extracellular concentrations similar to those observed in stationary phase cells, polyphosphate inhibits proteasome activity and proliferation, and induces aggregation...
February 20, 2019: Molecular Biology of the Cell
Michael Downey
During stress, bacterial cells activate a conserved pathway called the stringent response that promotes survival. Polyphosphates are long chains of inorganic phosphates that modulate this response in diverse bacterial species. In this issue (pgs. XXX-XXX) (1), Michael Gray provides an important correction to the model of how polyphosphate accumulation is regulated during the stringent response in E. coli. With other recent publications, this study provides a revised framework for understanding how bacterial polyphosphate dynamics might be exploited in infection control and industrial applications...
February 19, 2019: Journal of Bacteriology
Alexander S Reshetnikov, Natalia P Solntseva, Olga N Rozova, Ildar I Mustakhimov, Yuri A Trotsenko, Valentina N Khmelenina
The genes encoding adenosine triphosphate (ATP)- and polyphosphate (polyP)-dependent glucokinases (Glk) were identified in the aerobic obligate methanotroph Methylomonas sp. 12. The recombinant proteins were obtained by the heterologous expression of the glk genes in Esherichia coli . ATP-Glk behaved as a multimeric protein consisting of di-, tri-, tetra-, penta- and hexamers with a subunit molecular mass of 35.5 kDa. ATP-Glk phosphorylated glucose and glucosamine using ATP (100% activity), uridine triphosphate (UTP) (85%) or guanosine triphosphate (GTP) (71%) as a phosphoryl donor and exhibited the highest activity in the presence of 5 mM Mg2+ at pH 7...
February 14, 2019: Microorganisms
Ana B Lanham, Adrian Oehmen, Gilda Carvalho, Aaron M Saunders, Per H Nielsen, Maria A M Reis
A comprehensive assessment of full-scale enhanced biological phosphorus removal (EBPR) plants (five plants, 19 independent tests) was undertaken to determine their effectiveness in terms of aerobic and anoxic P removal. By comparing parallel P uptake tests under only aerobic or under anoxic-aerobic conditions, results revealed that introducing an anoxic stage led to an overall P removal of on average 90% of the P removed under only aerobic conditions. This was achieved with negligible higher PHA and glycogen requirements, 30% lower overall oxygen consumption and with the simultaneous removal of nitrate, reducing up to an estimate of 70% of carbon requirements for simultaneous N and P removal...
December 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Michael J Gray
Production of inorganic polyphosphate (polyP) by bacteria is triggered by a variety of different stress conditions. PolyP is required for stress survival and virulence in diverse pathogenic microbes. Previous studies have hypothesized a model for regulation of polyP synthesis in which production of the stringent response second messenger (p)ppGpp directly stimulates polyP accumulation. In this work, I have now shown that this model is incorrect, and (p)ppGpp is not required for polyP synthesis in Escherichia coli However, stringent mutations of RNA polymerase that frequently arise spontaneously in strains defective in (p)ppGpp synthesis and null mutations of the stringent response-associated transcription factor DksA both strongly inhibit polyP accumulation...
February 11, 2019: Journal of Bacteriology
Francesco De Rango, Paolina Crocco, Francesca Iannone, Adolfo Saiardi, Giuseppe Passarino, Serena Dato, Giuseppina Rose
Biogerontological research highlighted a complex and dynamic connection between aging, health and longevity, partially determined by genetic factors. Multifunctional proteins with moonlighting features, by integrating different cellular activities in the space and time, may explain part of this complexity. Inositol Polyphosphate Multikinase (IPMK) is a potential moonlighting protein performing multiple unrelated functions. Initially identified as a key enzyme for inositol phosphates synthesis, small messengers regulating many aspects of cell physiology, IPMK is now implicated in a number of metabolic pathways affecting the aging process...
February 8, 2019: Genes
Haipeng Jiang, Mingshu Bi, Daqing Ma, Bei Li, Haiyong Cong, Wei Gao
The suppression effect of melamine cyanurate (MCA) and melamine polyphosphate (MPP) on the flame propagation of aluminum dust were studied experimentally. The results indicated that the concentration of MPP required to supress the aluminum dust explosion was lower than MCA. As the concentration of suppressant increased, the acceleration and the maximum flame speed extremely decreased, and the flame morphology became isolated spot flames. The MPP addition exerted a stronger suppression effect on the temperature of aluminum flame compared to MCA addition...
February 1, 2019: Journal of Hazardous Materials
Alejandra Guadalupe Acosta-Cortés, Cesar Martinez-Ledezma, Ulrico Javier López-Chuken, Garima Kaushik, Surendra Nimesh, Juan Francisco Villarreal-Chiu
Seven bacterial strains isolated from a glyphosate-exposed orange plantation site were exposed to 1 mM N-(phosphonomethyl)glycine supplied as a phosphorus source. While some exhibited good biodegradation profiles, the strain 6 P, identified as Bacillus cereus, was the only strain capable of releasing inorganic phosphate to the culture supernatant, while accumulating polyphosphate intracellularly along the experimentation time. The composition and purity of the intracellular polyphosphate accumulated by the strain 6 P were confirmed by FTIR analysis...
February 11, 2019: ISME Journal
Arya Pokhrel, Jordan C Lingo, Frank Wolschendorf, Michael J Gray
Inorganic polyphosphate (polyP) is a biological polymer found in cells from all domains of life, and is required for virulence and stress response in many bacteria. There are a variety of methods for quantifying polyP in biological materials, many of which are either labor-intensive or insensitive, limiting their usefulness. We present here a streamlined method for polyP quantification in bacteria, using a silica membrane column extraction optimized for rapid processing of multiple samples, digestion of polyP with the polyP-specific exopolyphosphatase ScPPX, and detection of the resulting free phosphate with a sensitive ascorbic acid-based colorimetric assay...
January 21, 2019: Journal of Visualized Experiments: JoVE
Caifeng Jiao, Zhenxin Gu
It has been shown that 15 μW·cm-2 UV-B radiation has the most pronounced effects on γ-aminobutiric acid (GABA), inositol 1,4,5-trisphosphate (IP3) and abscisic acid (ABA) accumulation in 4-day-old soybean sprouts. Nevertheless, its mechanism of action, from the perspective of protein expression, remains largely unknown. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) were employed to investigate UV-B treatment-induced proteomic changes in soybean sprouts. Results showed that UV-B treatment effectively regulated proteins involved in GABA biosynthesis, such as glutamate synthase, glutamate decarboxylase (GAD), methionine synthetase, 5-methyltetrahydropteroyltriglutamate--homocysteine methyltransferase, aminoaldehyde dehydrogenase (AMADH) and inositol phosphate metabolism pathways, including phosphoinositide phospholipase C (PI-PLC), purple acid phosphatase (PAP) and inositol polyphosphate 5-phosphatase...
March 1, 2019: Food Chemistry
Jonas Johannes Christ, Lars Mathias Blank
Currently, inorganic polyphosphate is chemically synthesized from phosphate rock and added directly to food products. Yeast extract is a concentrate of soluble fractions of Saccharomyces cerevisiae and is, as a food additive, generally regarded as safe. The aim of this study was to biotechnologically produce a naturally polyphosphate-rich yeast extract. Polyphosphate-rich cells were produced with a wild type (non-GMO) S. cerevisiae by orthophosphate-starvation and subsequent orthophosphate-feeding, and contained 28% (w/w) polyphosphate (as KPO3) in cell dry weight, which is the highest content reported so far...
February 4, 2019: FEMS Yeast Research
Caifeng Jiao, Zhenxin Gu
Abscisic acid (ABA), as a sesquiterpenoid hormone, could regulate lots of physiological processes, especially secondary metabolism in plants. Nevertheless, its mechanism of action, from the perspective of protein expression, remains largely unknown. In the study, isobaric tags for relative and absolute quantitation (iTRAQ) was employed to investigate ABA treatment-induced proteomic changes related to secondary metabolism in soybean sprouts. Among the 3033 proteins identified, compared with the control, ABA treatment up- and down-regulated 350 proteins...
February 2019: Food Research International
David Ross, David Deamer
Polymerization of nucleotides and amino acids to form large, complex, and potentially functional products was an early and essential event on the paths leading to life's origin. The standard Gibbs energies of the condensation reactions are uphill, however, and at equilibrium will yield only declining sequences of small, nonfunctional oligomers. Geochemically produced condensing agents such as carbonyl sulfide, cyanamide, and polyphosphates have been proposed to invert the unfavorable condensation Gibbs energies and thereby activate exergonic condensation...
February 1, 2019: Astrobiology
Guangxin Feng, Mingyong Zeng, Min Huang, Suqin Zhu, Wei Guo, Haohao Wu
Biogenic polyphosphate nanoparticles (BPNPs) from Synechococcus sp. PCC 7002 have been found to exhibit intestinal protective potential in vitro and ex vivo. The aim of this study was to evaluate the in vivo intestinal protective effect of BPNPs in experimental colitis. BPNPs were intragastrically administered to C57BL/6 mice daily for 9 d during and after 5 d dextran sodium sulfate (DSS) exposure. Based on the body weight, disease activity index, colon length and colon histology, BPNPs effectively ameliorated DSS-induced colitis in mice...
February 1, 2019: Food & Function
Liang Wang, Qinghua Liu, Xiang Wu, Yue Huang, Michael J Wise, Zhanzhong Liu, Wei Wang, Junfeng Hu, Chunying Wang
Energy storage compounds play crucial roles in prokaryotic physiology. Five chemical compounds have been identified in prokaryotes as energy reserves: polyphosphate (polyP), polyhydroxyalkanoates (PHAs), glycogen, wax ester (WE) and triacylglycerol (TAG). Currently, no systematic study of archaeal energy storage metabolism exists. In this study, we collected 427 archaeal reference sequences from UniProt database. A thorough pathway screening of energy reserves led to an overview of distribution patterns of energy metabolism in archaea...
January 31, 2019: Scientific Reports
Emad Tolba, Xiaohong Wang, Maximilian Ackermann, Meik Neufurth, Rafael Muñoz-Espí, Heinz C Schröder, Werner E G Müller
The preparation and characterization of a porous hybrid cryogel based on the two organic polymers, poly(vinyl alcohol) (PVA) and karaya gum (KG), into which polyphosphate (polyP) nanoparticles have been incorporated, are described. The PVA/KG cryogel is prepared by intermolecular cross-linking of PVA via freeze-thawing and Ca2+ -mediated ionic gelation of KG to form stable salt bridges. The incorporation of polyP as amorphous nanoparticles with Ca2+ ions (Ca-polyP-NP) is achieved using an in situ approach. The polyP constituent does not significantly affect the viscoelastic properties of the PVA/KG cryogel that are comparable to natural soft tissue...
January 23, 2019: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Jina Park, Francesco Longo, Seung Ju Park, Seulgi Lee, Mihyun Bae, Richa Tyagi, Jin-Hee Han, Seyun Kim, Emanuela Santini, Eric Klann, Solomon H Snyder
Inositol polyphosphate multikinase (IPMK), the key enzyme for the biosynthesis of higher inositol polyphosphates and phosphatidylinositol 3,4,5 - trisphosphate, also acts as a versatile signaling player in regulating tissue growth and metabolism. To elucidate neurobehavioral functions of IPMK, we generated mice in which IPMK was deleted from the excitatory neurons of the postnatal forebrain. These mice showed no deficits in either novel object recognition or spatial memory. IPMK conditional knockout mice formed cued fear memory normally but displayed enhanced fear extinction...
January 28, 2019: Proceedings of the National Academy of Sciences of the United States of America
Jyoti Singh, Nicole Steck, Debaditya De, Alexandre Hofer, Alexander Ripp, Ilya Captain, Manfred Keller, Paul Wender, Rashna Bhandari, Henning Jacob Jessen
An iterative polyphosphorylation approach is described, which is based on a phosphoramidite (P-amidite) derived reagent (c-PyPA) obtained from the cyclization of pyrophosphate with a reactive diisopropylamino dichlorophosphine. This type of reagent is unprecedented as it represents a reactive P-amidite without protecting groups. The reagent proved to be stable in solution over several weeks. Its utility is described in the context of iterative monodirectional and bidirectional polyphosphorylations. The ensuing functionalized cyclotriphosphate can be opened with a variety of nucleophiles providing ready access to diverse functionalized polyphosphate chains of defined length with several tags, including both P-N and P-O labels...
January 25, 2019: Angewandte Chemie
Sebastian Rabe, Guadalupe Sanchez-Olivares, Ricardo Pérez-Chávez, Bernhard Schartel
Natural keratin fibres derived from Mexican tannery waste and coconut fibres from coconut processing waste were used as fillers in commercially available, biodegradable thermoplastic starch-polyester blend to obtain sustainable biocomposites. The morphology, rheological and mechanical properties as well as pyrolysis, flammability and forced flaming combustion behaviour of those biocomposites were investigated. In order to open up new application areas for these kinds of biocomposites, ammonium polyphosphate (APP) was added as a flame retardant...
January 22, 2019: Materials
Natalia Rey-Martínez, Marina Badia-Fabregat, Albert Guisasola, Juan Antonio Baeza
Enhanced Biological Phosphorus Removal (EBPR) is based on the enrichment of sludge in polyphosphate accumulating organisms (PAO). Candidatus Accumulibacter is the bacterial community member most commonly identified as PAO in EBPR systems when volatile fatty acids (VFA) are the carbon source. However, it is necessary to understand the role of non-Accumulibacter PAO in the case of wastewater with low VFA content. This work shows the first successful long-term operation of an EBPR system with glutamate as sole carbon and nitrogen source, resulting in the enrichment of sludge in the genus Thiothrix (37%), the family Comamonadaceae (15...
March 20, 2019: Science of the Total Environment
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