scholarly journals Inorganic polyphosphate in mammals: where's Wally?

2020 ◽  
Vol 48 (1) ◽  
pp. 95-101 ◽  
Author(s):  
Yann Desfougères ◽  
Adolfo Saiardi ◽  
Cristina Azevedo
Keyword(s):  
Mammalian Cells ◽  
Biosynthetic Pathway ◽  
High Energy ◽  
Detection Methods ◽  
Polyp Detection ◽  
Inorganic Polyphosphate ◽  
Mammalian Enzyme ◽  
Higher Eukaryotes ◽  
Low Sensitivity ◽  
Current Detection

Inorganic polyphosphate (polyP) is a ubiquitous polymer of tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. In prokaryotes and lower eukaryotes, both the presence of polyP and of the biosynthetic pathway that leads to its synthesis are well-documented. However, in mammals, polyP is more elusive. Firstly, the mammalian enzyme responsible for the synthesis of this linear biopolymer is unknown. Secondly, the low sensitivity and specificity of available polyP detection methods make it difficult to confidently ascertain polyP presence in mammalian cells, since in higher eukaryotes, polyP exists in lower amounts than in yeast or bacteria. Despite this, polyP has been given a remarkably large number of functions in mammals. In this review, we discuss some of the proposed functions of polyP in mammals, the limitations of the current detection methods and the urgent need to understand how this polymer is synthesized.

Functions of inorganic polyphosphates in eukaryotic cells: a coat of many colours

2014 ◽  
Vol 42 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Cristina Azevedo ◽  
Adolfo Saiardi
Keyword(s):  
High Energy ◽  
Linear Polymer ◽  
Detection Methods ◽  
Eukaryotic Cells ◽  
Inorganic Polyphosphates ◽  
Inorganic Polyphosphate ◽  
Structural Functions ◽  
Higher Eukaryotes ◽  
Living Organisms ◽  
And Function

PolyP (inorganic polyphosphate) is a linear polymer of tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. This polymer is present in all living organisms from bacteria to mammals. Until recently, most of the studies on polyP have focused on its function in prokaryotes. In prokaryotes, polyP has been implicated in many unrelated processes ranging from basic metabolism to structural functions. However, polyP analysis and function in higher eukaryotes has been gaining momentum recently. In the present review, we mainly aim to discuss the proposed intracellular functions of polyP in higher eukaryotes and its detection methods.

scholarly journals Behavior ofYersinia enterocoliticain Foods

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Md. Latiful Bari ◽  
M. Anwar Hossain ◽  
Kenji Isshiki ◽  
Dike Ukuku
Keyword(s):  
Mammalian Cells ◽  
Environmental Water ◽  
Detection Methods ◽  
Food Hygiene ◽  
Virulent Strains ◽  
Chromosomal Genes ◽  
Untreated Water ◽  
Contaminated Food ◽  
Low Sensitivity ◽  
Limited Sensitivity

Yersinia enterocoliticaare ubiquitous, being isolated frequently from soil, water, animals, and a variety of foods. They comprise a biochemically heterogeneous group that can survive and grow at refrigeration temperatures. The ability to propagate at refrigeration temperatures is of considerable significance in food hygiene. Virulent strains ofYersiniainvade mammalian cells such as HeLa cells in tissue culture. Two chromosomal genes, inv and ail, were identified for cell invasion of mammalian. The pathogen can cause diarrhoea, appendicitis and post-infection arthritis may occur in a small proportion of cases. The most common transmission route of pathogenicY. enterocoliticais thought to be fecal-oral via contaminated food. Direct person-to-person contact is rare. Occasionally, pathogenicY. enterocoliticahas been detected in vegetables and environmental water; thus, vegetables and untreated water are also potential sources of human yersiniosis. However, the isolation rates of pathogenicY. enterocoliticahave been low, which may be due to the limited sensitivity of the detection methods. To identify other possible transmission vehicles, different food items should be studied more extensively. Many factors related to the epidemiology ofY. enterocolitica, such as sources, transmission routes, and predominating genotypes remain obscure because of the low sensitivity of detection methods.

Role of inorganic polyphosphate in mammalian cells: from signal transduction and mitochondrial metabolism to cell death

2016 ◽  
Vol 44 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Plamena R. Angelova ◽  
Artyom Y. Baev ◽  
Alexey V. Berezhnov ◽  
Andrey Y. Abramov
Keyword(s):  
Signal Transduction ◽  
Cell Death ◽  
Mammalian Cells ◽  
High Energy ◽  
Mitochondrial Metabolism ◽  
Calcium Handling ◽  
Calcium Signal ◽  
Inorganic Polyphosphate ◽  
Long Chain

Inorganic polyphosphate (polyP) is a polymer compromised of linearly arranged orthophosphate units that are linked through high-energy phosphoanhydride bonds. The chain length of this polymer varies from five to several thousand orthophosphates. PolyP is distributed in the most of the living organisms and plays multiple functions in mammalian cells, it is important for blood coagulation, cancer, calcium precipitation, immune response and many others. Essential role of polyP is shown for mitochondria, from implication into energy metabolism and mitochondrial calcium handling to activation of permeability transition pore (PTP) and cell death. PolyP is a gliotransmitter which transmits the signal in astrocytes via activation of P2Y1 receptors and stimulation of phospholipase C. PolyP-induced calcium signal in astrocytes can be stimulated by different lengths of this polymer but only long chain polyP induces mitochondrial depolarization by inhibition of respiration and opening of the PTP. It leads to induction of astrocytic cell death which can be prevented by inhibition of PTP with cyclosporine A. Thus, medium- and short-length polyP plays role in signal transduction and mitochondrial metabolism of astrocytes and long chain of this polymer can be toxic for the cells.

scholarly journals Depletion of mitochondrial inorganic polyphosphate (polyP) in mammalian cells causes metabolic shift from oxidative phosphorylation to glycolysis.

2021 ◽  
Author(s):  
Maria E. Solesio ◽  
Lihan Xie ◽  
Brendan McIntyre ◽  
Mathew Ellenberger ◽  
Erna Mitaishvili ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Oxidative Phosphorylation ◽  
Mammalian Cells ◽  
High Energy ◽  
Hek293 Cells ◽  
Wild Type ◽  
Inorganic Polyphosphate ◽  
Metabolic Switch ◽  
Respiratory Parameters ◽  
Respiratory Chain Activity

Inorganic polyphosphate (polyP) is a linear polymer composed of up to a few hundred orthophosphates linked together by high-energy phosphoanhydride bonds, identical to those found in ATP. In mammalian mitochondria, polyP has been implicated in multiple processes, including energy metabolism, ion channels function, and the regulation of calcium signaling. However, the specific mechanisms of all these effects of polyP within the organelle remain poorly understood. The central goal of this study was to investigate how mitochondrial polyP participates in the regulation of the mammalian cellular energy metabolism. To accomplish this, we created HEK293 cells depleted of mitochondrial polyP, through the stable expression of the polyP hydrolyzing enzyme (scPPX). We found that these cells have significantly reduced rates of oxidative phosphorylation (OXPHOS), while their rates of glycolysis were elevated. Consistent with this, metabolomics assays confirmed increased levels of metabolites involved in glycolysis in these cells, compared with the wild-type samples. At the same time, key respiratory parameters of the isolated mitochondria were unchanged, suggesting that respiratory chain activity is not affected by the lack of mitochondrial polyP. However, we detected that mitochondria from cells that lack mitochondrial polyP are more fragmented when compared with those from wild-type cells. Based on these results, we propose that mitochondrial polyP plays an important role as a regulator of the metabolic switch between OXPHOS and glycolysis.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

Phosphate, inositol and polyphosphates

2016 ◽  
Vol 44 (1) ◽  
pp. 253-259 ◽  
Author(s):  
Thomas M. Livermore ◽  
Cristina Azevedo ◽  
Bernadett Kolozsvari ◽  
Miranda S.C. Wilson ◽  
Adolfo Saiardi
Keyword(s):  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
High Energy ◽  
Inorganic Polyphosphate ◽  
Covalent Bonds ◽  
Polymeric Form ◽  
Phosphodiester Bond ◽  
Signalling Molecules ◽  
Inositol Ring ◽  
Phosphate Groups

Eukaryotic cells have ubiquitously utilized the myo-inositol backbone to generate a diverse array of signalling molecules. This is achieved by arranging phosphate groups around the six-carbon inositol ring. There is virtually no biological process that does not take advantage of the uniquely variable architecture of phosphorylated inositol. In inositol biology, phosphates are able to form three distinct covalent bonds: phosphoester, phosphodiester and phosphoanhydride bonds, with each providing different properties. The phosphoester bond links phosphate groups to the inositol ring, the variable arrangement of which forms the basis of the signalling capacity of the inositol phosphates. Phosphate groups can also form the structural bridge between myo-inositol and diacylglycerol through the phosphodiester bond. The resulting lipid-bound inositol phosphates, or phosphoinositides, further expand the signalling potential of this family of molecules. Finally, inositol is also notable for its ability to host more phosphates than it has carbons. These unusual organic molecules are commonly referred to as the inositol pyrophosphates (PP-IPs), due to the presence of high-energy phosphoanhydride bonds (pyro- or diphospho-). PP-IPs themselves constitute a varied family of molecules with one or more pyrophosphate moiety/ies located around the inositol. Considering the relationship between phosphate and inositol, it is no surprise that members of the inositol phosphate family also regulate cellular phosphate homoeostasis. Notably, the PP-IPs play a fundamental role in controlling the metabolism of the ancient polymeric form of phosphate, inorganic polyphosphate (polyP). Here we explore the intimate links between phosphate, inositol phosphates and polyP, speculating on the evolution of these relationships.

scholarly journals Trypanosoma cruziCalreticulin Is a Lectin That Binds Monoglucosylated Oligosaccharides but Not Protein Moieties of Glycoproteins

1999 ◽  
Vol 10 (5) ◽  
pp. 1381-1394 ◽  
Author(s):  
Carlos Labriola ◽  
Juan J. Cazzulo ◽  
Armando J. Parodi
Keyword(s):  
Quality Control ◽  
Mammalian Cells ◽  
Protozoan Parasite ◽  
Glucosidase Ii ◽  
The Third ◽  
Oligosaccharide Processing ◽  
Encoding Gene ◽  
Higher Eukaryotes ◽  
Lysosomal Proteinase ◽  
Protein Moiety

Trypanosoma cruzi is a protozoan parasite that belongs to an early branch in evolution. Although it lacks several features of the pathway of protein N-glycosylation and oligosaccharide processing present in the endoplasmic reticulum of higher eukaryotes, it displays UDP-Glc:glycoprotein glucosyltransferase and glucosidase II activities. It is herewith reported that this protozoan also expresses a calreticulin-like molecule, the third component of the quality control of glycoprotein folding. No calnexin-encoding gene was detected. Recombinant T. cruzi calreticulin specifically recognized free monoglucosylated high-mannose-type oligosaccharides. Addition of anti-calreticulin serum to extracts obtained from cells pulse–chased with [35S]Met plus [35S]Cys immunoprecipitated two proteins that were identified as calreticulin and the lysosomal proteinase cruzipain (a major soluble glycoprotein). The latter but not the former protein disappeared from immunoprecipitates upon chasing cells. Contrary to what happens in mammalian cells, addition of the glucosidase II inhibitor 1-deoxynojirimycin promoted calreticulin–cruzipain interaction. This result is consistent with the known pathway of proteinN-glycosylation and oligosaccharide processing occurring in T. cruzi. A treatment of the calreticulin-cruzipain complexes with endo-β-N-acetylglucosaminidase H either before or after addition of anti-calreticulin serum completely disrupted calreticulin–cruzipain interaction. In addition, mature monoglucosylated but not unglucosylated cruzipain isolated from lysosomes was found to interact with recombinant calreticulin. It was concluded that the quality control of glycoprotein folding appeared early in evolution, and that T. cruzi calreticulin binds monoglucosylated oligosaccharides but not the protein moiety of cruzipain. Furthermore, evidence is presented indicating that glucosyltransferase glucosylated cruzipain at its last folding stages.

scholarly journals Molecular beacons allow specific RT-LAMP detection of B.1.1.7 variant SARS-CoV-2

2021 ◽  
Author(s):  
Scott Sherrill-Mix ◽  
Gregory D. Van Duyne ◽  
Frederic D. Bushman
Keyword(s):  
Genetic Variants ◽  
Molecular Beacons ◽  
Spike Protein ◽  
Detection Methods ◽  
Gene Encoding ◽  
Detection And Identification ◽  
Rapid Spread ◽  
The World ◽  
Primer Sets ◽  
Current Detection

AbstractOver the course of the COVID-19 pandemic, several SARS-CoV-2 genetic variants of concern have appeared and spread throughout the world. Detection and identification of these variants is important to understanding and controlling their rapid spread. Current detection methods for a particularly concerning variant, B.1.1.7, require expensive qPCR machines and depend on the absence of a signal rather than a positive indicator of variant presence. Here we report an assay using a pair of molecular beacons paired with reverse transcription loop mediated amplification to allow isothermal amplification from saliva to specifically detect B.1.1.7 and other variants which contain a characteristic deletion in the gene encoding the viral spike protein. This assay is specific, affordable and allows multiplexing with other SARS-CoV-2 LAMP primer sets.

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