scholarly journals Lipid Interactions Between Flaviviruses and Mosquito Vectors

2021 ◽  
Vol 12 ◽  
Author(s):  
Thomas Vial ◽  
Guillaume Marti ◽  
Dorothée Missé ◽  
Julien Pompon
Keyword(s):  
Physicochemical Properties ◽  
De Novo ◽  
Biochemical Properties ◽  
Virus Multiplication ◽  
Intervention Strategies ◽  
Human Populations ◽  
Mosquito Vectors ◽  
Membrane Behavior ◽  
Lipid Interactions ◽  
Acyl Chains

Mosquito-borne flaviviruses, such as dengue (DENV), Zika (ZIKV), yellow fever (YFV), West Nile (WNV), and Japanese encephalitis (JEV) viruses, threaten a large part of the human populations. In absence of therapeutics and effective vaccines against each flaviviruses, targeting viral metabolic requirements in mosquitoes may hold the key to new intervention strategies. Development of metabolomics in the last decade opened a new field of research: mosquito metabolomics. It is now clear that flaviviruses rely on mosquito lipids, especially phospholipids, for their cellular cycle and propagation. Here, we review the biosyntheses of, biochemical properties of and flaviviral interactions with mosquito phospholipids. Phospholipids are structural lipids with a polar headgroup and apolar acyl chains, enabling the formation of lipid bilayer that form plasma- and endomembranes. Phospholipids are mostly synthesized through the de novo pathway and remodeling cycle. Variations in headgroup and acyl chains influence phospholipid physicochemical properties and consequently the membrane behavior. Flaviviruses interact with cellular membranes at every step of their cellular cycle. Recent evidence demonstrates that flaviviruses reconfigure the phospholipidome in mosquitoes by regulating phospholipid syntheses to increase virus multiplication. Identifying the phospholipids involved and understanding how flaviviruses regulate these in mosquitoes is required to design new interventions.

scholarly journals A study of transposable element-associated structural variations (TASVs) using a de novo-assembled Korean genome

2021 ◽  
Author(s):  
Seyoung Mun ◽  
Songmi Kim ◽  
Wooseok Lee ◽  
Keunsoo Kang ◽  
Thomas J. Meyer ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Genome Assembly ◽  
De Novo ◽  
Personal Genome ◽  
Human Populations ◽  
Whole Genome ◽  
Structural Variations ◽  
Insert Size ◽  
Human Genomes ◽  
Next Generation Sequencing Ngs

AbstractAdvances in next-generation sequencing (NGS) technology have made personal genome sequencing possible, and indeed, many individual human genomes have now been sequenced. Comparisons of these individual genomes have revealed substantial genomic differences between human populations as well as between individuals from closely related ethnic groups. Transposable elements (TEs) are known to be one of the major sources of these variations and act through various mechanisms, including de novo insertion, insertion-mediated deletion, and TE–TE recombination-mediated deletion. In this study, we carried out de novo whole-genome sequencing of one Korean individual (KPGP9) via multiple insert-size libraries. The de novo whole-genome assembly resulted in 31,305 scaffolds with a scaffold N50 size of 13.23 Mb. Furthermore, through computational data analysis and experimental verification, we revealed that 182 TE-associated structural variation (TASV) insertions and 89 TASV deletions contributed 64,232 bp in sequence gain and 82,772 bp in sequence loss, respectively, in the KPGP9 genome relative to the hg19 reference genome. We also verified structural differences associated with TASVs by comparative analysis with TASVs in recent genomes (AK1 and TCGA genomes) and reported their details. Here, we constructed a new Korean de novo whole-genome assembly and provide the first study, to our knowledge, focused on the identification of TASVs in an individual Korean genome. Our findings again highlight the role of TEs as a major driver of structural variations in human individual genomes.

scholarly journals Lipid Acyl Chain Remodeling in Yeast

2015 ◽  
Vol 8s1 ◽  
pp. LPI.S31780 ◽  
Author(s):  
Mike F. Renne ◽  
Xue Bao ◽  
Cedric H. De Smet ◽  
Anton I. P. M. De Kroon
Keyword(s):  
Intracellular Transport ◽  
De Novo ◽  
Acyl Chain ◽  
Model Organism ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Lipid Homeostasis ◽  
Synthetic Process ◽  
Acyl Chains ◽  
Phospholipid Acyl Chain

Membrane lipid homeostasis is maintained by de novo synthesis, intracellular transport, remodeling, and degradation of lipid molecules. Glycerophospholipids, the most abundant structural component of eukaryotic membranes, are subject to acyl chain remodeling, which is defined as the post-synthetic process in which one or both acyl chains are exchanged. Here, we review studies addressing acyl chain remodeling of membrane glycerophospholipids in Saccharomyces cerevisiae, a model organism that has been successfully used to investigate lipid synthesis and its regulation. Experimental evidence for the occurrence of phospholipid acyl chain exchange in cardiolipin, phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine is summarized, including methods and tools that have been used for detecting remodeling. Progress in the identification of the enzymes involved is reported, and putative functions of acyl chain remodeling in yeast are discussed.

scholarly journals High light induces species specific changes in the membrane lipid composition of Chlorella

2020 ◽  
Vol 477 (13) ◽  
pp. 2543-2559
Author(s):  
Janka Widzgowski ◽  
Alexander Vogel ◽  
Lena Altrogge ◽  
Julia Pfaff ◽  
Heiko Schoof ◽  
...  
Keyword(s):  
Cell Membranes ◽  
De Novo ◽  
Algal Cell ◽  
Isotopic Labeling ◽  
Biochemical Properties ◽  
Membrane Lipid ◽  
Light Conditions ◽  
Hydrophobic Barrier ◽  
Glycerolipid Composition ◽  
Species Specific

Algae have evolved several mechanisms to adjust to changing environmental conditions. To separate from their surroundings, algal cell membranes form a hydrophobic barrier that is critical for life. Thus, it is important to maintain or adjust the physical and biochemical properties of cell membranes which are exposed to environmental factors. Especially glycerolipids of thylakoid membranes, the site of photosynthesis and photoprotection within chloroplasts, are affected by different light conditions. Since little is known about membrane lipid remodeling upon different light treatments, we examined light induced alterations in the glycerolipid composition of the two Chlorella species, C. vulgaris and C. sorokiniana, which differ strongly in their ability to cope with different light intensities. Lipidomic analysis and isotopic labeling experiments revealed differences in the composition of their galactolipid species, although both species likely utilize galactolipid precursors originated from the endoplasmic reticulum. However, in silico research of de novo sequenced genomes and ortholog mapping of proteins putatively involved in lipid metabolism showed largely conserved lipid biosynthesis pathways suggesting species specific lipid remodeling mechanisms, which possibly have an impact on the response to different light conditions.

Interaction of normal and mutant SRY proteins with DNA

1995 ◽  
Vol 350 (1333) ◽  
pp. 215-220 ◽  
Keyword(s):  
De Novo ◽  
Spatial Arrangement ◽  
Biochemical Properties ◽  
Chromatin Protein ◽  
Dna Structures ◽  
Testis Differentiation ◽  
Expression Of Genes ◽  
Target Sites ◽  
Nucleoprotein Complex ◽  
Complete Gonadal Dysgenesis

In mammals, sex determination is caused by the Y-chromosome gene SRY . The DNA-binding domain of human SRY protein is similar to those of the chromatin protein HMG1. Like HMG1, SRY binds to kinked DNA structures, and bends linear DNA sharply upon binding. We analysed the biochemical properties of mutant SRY proteins from five patients with complete gonadal dysgenesis: two bind and bend DNA almost normally, two bind inefficiently but bend DNA normally, and one binds DNA with almost normal affinity but produces a different angle. The mutations with moderate effect on complex formation can be transmitted to progeny, the ones with severe effects on either binding or bending are de novo . The angle induced by SRY depends on the exact DNA sequence, thus discriminating different target sites. We suggest that the exact spatial arrangement of the nucleoprotein complex organized by SRY in chromatin is essential for the expression of genes involved in testis differentiation.

scholarly journals Aflatoxin Exposure in Developing Countries: The Critical Interface of Agriculture and Health

2007 ◽  
Vol 28 (2_suppl2) ◽  
pp. S372-S380 ◽  
Author(s):  
Christopher Paul Wild
Keyword(s):  
West Africa ◽  
Relevant Literature ◽  
Intervention Strategies ◽  
Sub Saharan Africa ◽  
Farm Animals ◽  
Human Populations ◽  
Growth Faltering ◽  
Sub Saharan ◽  
Underlying Mechanisms ◽  
Agricultural Setting

Background Aflatoxins are common contaminants of staple foods in sub-Saharan Africa. These toxins are human liver carcinogens, especially in combination with chronic infection with hepatitis B virus. However, in an agricultural setting, the effects on growth, immune status, and susceptibility to infectious disease in farm animals are also well recognized. These latter effects have been far less explored in human populations. Objectives To review some of the more recent work on aflatoxins where the health outcomes seen in the agricultural setting, including growth impairment and immune suppression, have been investigated in human populations. The paper draws largely on examples from West Africa. The paper also sets out how knowledge gained about aflatoxins in the agricultural setting can be used to design intervention studies in human populations. Methods A review of the relevant literature. Results Human exposure to aflatoxins begins early in life, and recent studies in West Africa have demonstrated an association between exposure and growth faltering, particularly stunting, in young children. At present the underlying mechanisms for the latter effects are unknown but may include impairment of immunity and increased susceptibility to infections. Simple postharvest intervention strategies were successful in reducing aflatoxin exposure in a subsistence farm setting, providing a rationale for prevention of aflatoxin-related disease. Conclusions There are potential benefits to public health from intervention strategies combining expertise in the agricultural and health settings to address the aflatoxin problem.

scholarly journals A direct multi-generational estimate of the human mutation rate from autozygous segments seen in thousands of parentally related individuals

2016 ◽  
Author(s):  
Vagheesh M Narasimhan ◽  
Raheleh Rahbari ◽  
Aylwyn Scally ◽  
Arthur Wuster ◽  
Dan Mason ◽  
...  
Keyword(s):  
Mutation Rate ◽  
Base Pair ◽  
De Novo ◽  
Recent Common Ancestor ◽  
Human Populations ◽  
De Novo Mutations ◽  
Pakistani Population ◽  
Human Mutation ◽  
C To T Mutations ◽  
Mutational Processes

AbstractHeterozygous mutations within homozygous sequences descended from a recent common ancestor offer a way to ascertain de novo mutations (DNMs) across multiple generations. Using exome sequences from 3,222 British-Pakistani individuals with high parental relatedness, we estimate a mutation rate of 1. 45 ± 0.05 × 10−8 per base pair per generation in autosomal coding sequence, with a corresponding noncrossover gene conversion rate of 8.75 ± 0.05 × 10−6 per base pair per generation. This is at the lower end of exome mutation rates previously estimated in parent-offspring trios, suggesting that post-zygotic mutations contribute little to the human germline mutation rate. We found frequent recurrence of mutations at polymorphic CpG sites, and an increase in C to T mutations in a 5’ CCG 3’ → 5’ CTG 3’ context in the Pakistani population compared to Europeans, suggesting that mutational processes have evolved rapidly between human populations.

scholarly journals Phospholipid Remodeling in Physiology and Disease

2019 ◽  
Vol 81 (1) ◽  
pp. 165-188 ◽  
Author(s):  
Bo Wang ◽  
Peter Tontonoz
Keyword(s):  
Viral Infections ◽  
De Novo ◽  
Acyl Chain ◽  
Phospholipid Composition ◽  
Fatty Acyl ◽  
De Novo Lipogenesis ◽  
Lipid Absorption ◽  
Fatty Acyl Chain ◽  
Nonalcoholic Fatty Liver ◽  
Acyl Chains

Phospholipids are major constituents of biological membranes. The fatty acyl chain composition of phospholipids determines the biophysical properties of membranes and thereby affects their impact on biological processes. The composition of fatty acyl chains is also actively regulated through a deacylation and reacylation pathway called Lands’ cycle. Recent studies of mouse genetic models have demonstrated that lysophosphatidylcholine acyltransferases (LPCATs), which catalyze the incorporation of fatty acyl chains into the sn-2 site of phosphatidylcholine, play important roles in pathophysiology. Two LPCAT family members, LPCAT1 and LPCAT3, have been particularly well studied. LPCAT1 is crucial for proper lung function due to its role in pulmonary surfactant biosynthesis. LPCAT3 maintains systemic lipid homeostasis by regulating lipid absorption in intestine, lipoprotein secretion, and de novo lipogenesis in liver. Mounting evidence also suggests that changes in LPCAT activity may be potentially involved in pathological conditions, including nonalcoholic fatty liver disease, atherosclerosis, viral infections, and cancer. Pharmacological manipulation of LPCAT activity and membrane phospholipid composition may provide new therapeutic options for these conditions.

scholarly journals Vermicomposting: Tool for Sustainable Ruminant Manure Management

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
A. Nasiru ◽  
N. Ismail ◽  
M. H. Ibrahim
Keyword(s):  
Waste Management ◽  
Physicochemical Properties ◽  
Health Risks ◽  
Agricultural Soils ◽  
Raw Materials ◽  
Biological Properties ◽  
Biochemical Properties ◽  
Manure Management ◽  
Biomass Waste ◽  
Solid Biomass

Ruminants are important sources of meat and milk. Their production is associated with manure excretion. Estimates of over 3,900,000 million metric tonnes of manure are produced daily from ruminants worldwide. Storage and spread of this waste on land pose health risks and environmental problems. Efficient and sustainable way of handling ruminant manure is required. Composting and vermicomposting are considered two of the best techniques for solid biomass waste management. This paper presents vermicomposting as an effective tool for ruminant manure management. Vermicomposting is a mesophilic biooxidation and stabilisation process of organic materials that involves the joint action of earthworm and microorganism. Compared with composting, vermicomposting has higher rate of stabilisation and it is greatly modifying its physical and biochemical properties, with low C : N ratio and homogenous end product. It is also costeffective and ecofriendly waste management. Due to its innate biological, biochemical and physicochemical properties, vermicomposting can be used to promote sustainable ruminant manure management. Vermicomposts are excellent sources of biofertiliser and their addition improves the physiochemical and biological properties of agricultural soils. In addition, earthworms from the vermicomposting can be used as source of protein to fishes and monogastric animals. Vermicompost can also be used as raw materials for bioindustries.

scholarly journals The elongation of exogenous fatty acids and the control of phospholipid acyl chain length in Micrococcus cryophilus

1980 ◽  
Vol 188 (3) ◽  
pp. 585-592 ◽  
Author(s):  
S P Sandercock ◽  
N J Russell
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
De Novo ◽  
Acyl Chain ◽  
Psychrophilic Bacterium ◽  
Fatty Acid Elongation ◽  
Acyl Chain Length ◽  
Acyl Chains ◽  
Phospholipid Acyl Chain

The synthesis of fatty acids de novo from acetate and the elongation of exogenous satuated fatty acids (C12-C18) by the psychrophilic bacterium Micrococcus cryophilus (A.T.C.C. 15174) grown at 1 or 20 degrees C was investigated. M. cryophilus normally contains only C16 and C18 acyl chains in its phospholipids, and the C18/C16 ratio is altered by changes in growth temperature. The bacterium was shown to regulate strictly its phospholipid acyl chain length and to be capable of directly elongating myristate and palmitate, and possibly laurate, to a mixture of C16 and C18 acyl chains. Retroconversion of stearate into palmitate also occurred. Fatty acid elongation could be distinguished from fatty acid synthesis de novo by the greater sensitivity of fatty acid elongation to inhibition by NaAsO2 under conditions when the supply of ATP and reduced nicotinamide nucleotides was not limiting. It is suggested that phospholipid acyl chain length may be controlled by a membrane-bound elongase enzyme, which interconverts C16 and C18 fatty acids via a C14 intermediate; the activity of the enzyme could be regulated by membrane lipid fluidity.

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