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Journal of Microbiology (Seoul, Korea) Feb 2022Four novel Gram-negative, mesophilic, aerobic, motile, and cocci-shaped strains were isolated from tick samples (strains 546 and 573) and respiratory tracts of marmots...
Four novel Gram-negative, mesophilic, aerobic, motile, and cocci-shaped strains were isolated from tick samples (strains 546 and 573) and respiratory tracts of marmots (strains 1318 and 1311). The 16S rRNA gene sequencing revealed that strains 546 and 573 were 97.8% identical to Roseomonas wenyumeiae Z23, whereas strains 1311 and 1318 were 98.3% identical to Roseomonas ludipueritiae DSM 14915. In addition, a 98.0% identity was observed between strains 546 and 1318. Phylogenetic and phylogenomic analyses revealed that strains 546 and 573 clustered with R. wenyumeiae Z23, whereas strains 1311 and 1318 grouped with R. ludipueritiae DSM 14915. The average nucleotide identity between our isolates and members of the genus Roseomonas was below 95%. The genomic G+C content of strains 546 and 1318 was 70.9% and 69.3%, respectively. Diphosphatidylglycerol (DPG) and phosphatidylethanolamine (PE) were the major polar lipids, with Q-10 as the predominant respiratory quinone. According to all genotypic, phenotypic, phylogenetic, and phylogenomic analyses, the four strains represent two novel species of the genus Roseomonas, for which the names Roseomonas haemaphysalidis sp. nov. and Roseomonas marmotae sp. nov. are proposed, with 546 (= GDMCC 1.1780 = JCM 34187) and 1318 (= GDMCC 1.1781 = JCM 34188) as type strains, respectively.
Topics: Animals; Bacterial Typing Techniques; Base Composition; Cardiolipins; DNA, Bacterial; Marmota; Methylobacteriaceae; Phosphatidylethanolamines; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ticks
PubMed: 34826100
DOI: 10.1007/s12275-022-1428-1 -
International Journal of Systematic and... Nov 2022Two Gram-stain-negative, catalase- and oxidase-positive, and aerobic bacteria, strains MSW7 and MSW13, were isolated from seawater. Cells of strains MSW7 and MSW13 are...
Two Gram-stain-negative, catalase- and oxidase-positive, and aerobic bacteria, strains MSW7 and MSW13, were isolated from seawater. Cells of strains MSW7 and MSW13 are motile and non-motile rods, respectively. Strain MSW7 optimally grew at 25 °C and pH 7.0 and in the presence of 3 % (w/v) NaCl, whereas strain MSW13 optimally grew at 25 °C and pH 6.0-7.0 and in the presence of 2 % NaCl. As the sole respiratory quinone and the major fatty acids and polar lipids, strain MSW7 contained ubiquinone-8, C, C 8, C 8 and summed feature 3 (C 7 and/or C 6), and phosphatidylethanolamine and phosphatidylglycerol, respectively, whereas strain MSW13 contained menaquinone-6, C 6, iso-C, anteiso-C, and iso-C 3-OH, and phosphatidylethanolamine, respectively. The DNA G+C contents of strains MSW7 and MSW13 were 37.3 and 29.9 %, respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains MSW7 and MSW13 were most closely related to A3 and WP25 with 98.8 and 98.1 % sequence similarities, respectively. The average nucleotide identity and digital DNA-DNA hybridization values between strain MSW7 and A3 and between strain MSW13 and KACC 17473 were 73.6 and 22.6 % and 80.4 and 23.8 %, respectively. Based on phenotypic, chemotaxonomic and phylogenetic data, strains MSW7 and MSW13 represent novel species of the genera and , respectively, for which the names sp. nov. and sp. nov. are proposed, respectively. The type strains of sp. nov. and sp. nov. are MSW7 (=KACC 22339=JCM 35001) and MSW13 (=KACC 22341=JCM 35021), respectively.
Topics: Phosphatidylethanolamines; Fatty Acids; Phylogeny; RNA, Ribosomal, 16S; Sodium Chloride; DNA, Bacterial; Base Composition; Bacterial Typing Techniques; Sequence Analysis, DNA; Seawater; Alteromonadaceae; Vitamin K 2
PubMed: 36748488
DOI: 10.1099/ijsem.0.005620 -
The European Journal of Neuroscience Sep 2022Brain ageing has been related to a decrease in cellular metabolism, to an accumulation of misfolded proteins and to an alteration of the lipid membrane composition....
Brain ageing has been related to a decrease in cellular metabolism, to an accumulation of misfolded proteins and to an alteration of the lipid membrane composition. These alterations act as contributive aspects of age-related memory decline by reducing membrane excitability and neurotransmitter release. In this sense, precursors of phospholipids (PLs) can restore the physiological composition of cellular membranes and ameliorate the cellular defects associated with brain ageing. In particular, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) have been shown to restore mitochondrial function, reduce the accumulation of amyloid beta (Aβ) and, at the same time, provide the amount of acetylcholine needed to reduce memory deficit. Among PL precursors, alpha-glycerylphosphorylethanolamine (GPE) has shown to protect astrocytes from Aβ injuries and to slow-down ageing of human neural stem cells. GPE has been evaluated in aged human hippocampal neurons, which are implicated in learning and memory, and constitute a good in vitro model to investigate the beneficial properties of GPE. In order to mimic cellular ageing, the cells have been maintained 21 days in vitro and challenged with GPE. Results of the present paper showed GPE ability to increase PE and PC content, glucose uptake and the activity of the chain respiratory complex I and of the GSK-3β pathway. Moreover, the nootropic compound showed an increase in the transcriptional/protein levels of neurotrophic and well-being related genes. Finally, GPE counteracted the accumulation of ageing-related misfolded proteins (a-synuclein and tau). Overall, our data underline promising effects of GPE in counteracting cellular alterations related to brain ageing and cognitive decline.
Topics: Aged; Amyloid beta-Peptides; Ethanolamines; Glycogen Synthase Kinase 3 beta; Hippocampus; Humans; Neurons; Phosphatidylcholines; Phosphatidylethanolamines
PubMed: 35902984
DOI: 10.1111/ejn.15783 -
The Journal of Biological Chemistry Nov 2022Involved in triglyceride (TG) and glycerophospholipid metabolism, the liver plays a crucial physiological role in the human body both as a major metabolic integrator and...
Involved in triglyceride (TG) and glycerophospholipid metabolism, the liver plays a crucial physiological role in the human body both as a major metabolic integrator and a central hub for lipid and energy homeostasis. Metabolic disorders can be caused by various factors that promote abnormal lipid accumulation in storage organelles called lipid droplets (LDs), as in hepatic steatosis, a metabolic syndrome manifestation that can progress to a hepatocellular carcinoma, the most common primary liver malignancy worldwide. Modern life involves conditions that disrupt the biological clock, causing metabolic disorders and higher cancer risk. A circadian clock is present in the liver and in immortalized cell lines and temporally regulates physiological processes by driving transcriptional and metabolic rhythms. Here we investigated metabolic rhythms in HepG2 cells, a human hepatocellular carcinoma-derived cell line, and the link between these rhythms and the circadian clock in control (Bmal1-wildtype) and Bmal1-disrupted (B-D) cells having their molecular clock impaired. Rhythms in the expression of lipid-synthesizing enzymes ChoKα, Pcyt2, and Lipin1, in the metabolism of particular glycerophospholipids such as phosphatidylcholine (PC) and phosphatidylethanolamine, and in the phosphatidylcholine/phosphatidylethanolamine ratio and TG and LD content were observed in Bmal1-wildtype cells. By contrast, in the B-D model, the whole hepatic metabolism was severely altered with a significant reduction in the TG and LD content as well as in ChoKα and other related lipid enzymes. Together, our results suggest a very strong crosstalk between the molecular clock and lipid metabolism, which exhibits an exacerbated pathological condition in B-D cells.
Topics: Humans; Lipid Metabolism; ARNTL Transcription Factors; Phosphatidylethanolamines; Carcinoma, Hepatocellular; Circadian Rhythm; Liver Neoplasms; Circadian Clocks; Liver; Triglycerides; Phosphatidylcholines; Cell Line
PubMed: 36183836
DOI: 10.1016/j.jbc.2022.102551 -
Nature Communications Nov 2021Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of...
Latrotoxins (LaTXs) are presynaptic pore-forming neurotoxins found in the venom of Latrodectus spiders. The venom contains a toxic cocktail of seven LaTXs, with one of them targeting vertebrates (α-latrotoxin (α-LTX)), five specialized on insects (α, β, γ, δ, ε- latroinsectotoxins (LITs), and one on crustaceans (α-latrocrustatoxin (α-LCT)). LaTXs bind to specific receptors on the surface of neuronal cells, inducing the release of neurotransmitters either by directly stimulating exocytosis or by forming Ca-conductive tetrameric pores in the membrane. Despite extensive studies in the past decades, a high-resolution structure of a LaTX is not yet available and the precise mechanism of LaTX action remains unclear. Here, we report cryoEM structures of the α-LCT monomer and the δ-LIT dimer. The structures reveal that LaTXs are organized in four domains. A C-terminal domain of ankyrin-like repeats shields a central membrane insertion domain of six parallel α-helices. Both domains are flexibly linked via an N-terminal α-helical domain and a small β-sheet domain. A comparison between the structures suggests that oligomerization involves major conformational changes in LaTXs with longer C-terminal domains. Based on our data we propose a cyclic mechanism of oligomerization, taking place prior membrane insertion. Both recombinant α-LCT and δ-LIT form channels in artificial membrane bilayers, that are stabilized by Ca ions and allow calcium flux at negative membrane potentials. Our comparative analysis between α-LCT and δ-LIT provides first crucial insights towards understanding the molecular mechanism of the LaTX family.
Topics: Animals; Binding Sites; Black Widow Spider; Calcium; Cloning, Molecular; Cryoelectron Microscopy; Escherichia coli; Gene Expression; Genetic Vectors; Ion Transport; Lipid Bilayers; Membrane Potentials; Models, Molecular; Neurotoxins; Phosphatidylcholines; Phosphatidylethanolamines; Protein Binding; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; Protein Multimerization; Recombinant Proteins; Spider Venoms
PubMed: 34845192
DOI: 10.1038/s41467-021-26562-8 -
Current Protocols in Protein Science Sep 2020Peripheral membrane proteins participate in numerous biological pathways. Thus, methods to analyze their membrane-binding characteristics have become important. In this...
Peripheral membrane proteins participate in numerous biological pathways. Thus, methods to analyze their membrane-binding characteristics have become important. In this report, we detail protocols for the synthesis and utilization of a photoactivable fluorescent lipid as a reporter to monitor membrane binding of proteins. The assay, referred to as proximity-based labeling of membrane-associated proteins (PLiMAP), is based on UV activation of a fluorescent lipid reporter, which in turn crosslinks with proteins bound to membranes and renders them fluorescent. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Synthesis of BODIPY-diazirine phosphatidylethanolamine (BDPE) Basic Protocol 2: Preparation of BDPE-containing liposomes Basic Protocol 3: Performing PLiMAP with a candidate protein Basic Protocol 4: Quantitation of liposome-binding properties of the candidate protein from analyzing in-gel fluorescence Support Protocol: Purification of GST-2×P4M domain of SidM protein.
Topics: Animals; Boron Compounds; Cell Membrane; Diazomethane; Fluorescent Dyes; Humans; Liposomes; Membrane Proteins; Phosphatidylethanolamines; Phosphatidylinositol Phosphates; Photochemical Processes; Protein Binding; Spectrometry, Fluorescence
PubMed: 32603530
DOI: 10.1002/cpps.110 -
Angewandte Chemie (International Ed. in... Feb 2024The vast majority of membrane phospholipids (PLs) include two asymmetrically positioned fatty acyls: oxidizable polyunsaturated fatty acids (PUFA) attached predominantly...
Strikingly High Activity of 15-Lipoxygenase Towards Di-Polyunsaturated Arachidonoyl/Adrenoyl-Phosphatidylethanolamines Generates Peroxidation Signals of Ferroptotic Cell Death.
The vast majority of membrane phospholipids (PLs) include two asymmetrically positioned fatty acyls: oxidizable polyunsaturated fatty acids (PUFA) attached predominantly at the sn2 position, and non-oxidizable saturated/monounsaturated acids (SFA/MUFA) localized at the sn1 position. The peroxidation of PUFA-PLs, particularly sn2-arachidonoyl(AA)- and sn2-adrenoyl(AdA)-containing phosphatidylethanolamines (PE), has been associated with the execution of ferroptosis, a program of regulated cell death. There is a minor subpopulation (≈1-2 mol %) of doubly PUFA-acylated phospholipids (di-PUFA-PLs) whose role in ferroptosis remains enigmatic. Here we report that 15-lipoxygenase (15LOX) exhibits unexpectedly high pro-ferroptotic peroxidation activity towards di-PUFA-PEs. We revealed that peroxidation of several molecular species of di-PUFA-PEs occurred early in ferroptosis. Ferrostatin-1, a typical ferroptosis inhibitor, effectively prevented peroxidation of di-PUFA-PEs. Furthermore, co-incubation of cells with di-AA-PE and 15LOX produced PUFA-PE peroxidation and induced ferroptotic death. The decreased contents of di-PUFA-PEs in ACSL4 KO A375 cells was associated with lower levels of di-PUFA-PE peroxidation and enhanced resistance to ferroptosis. Thus, di-PUFA-PE species are newly identified phospholipid peroxidation substrates and regulators of ferroptosis, representing a promising therapeutic target for many diseases related to ferroptotic death.
Topics: Phosphatidylethanolamines; Arachidonate 15-Lipoxygenase; Cell Death; Phospholipids; Fatty Acids, Unsaturated; Lipid Peroxidation
PubMed: 38230815
DOI: 10.1002/anie.202314710 -
Methods in Cell Biology 2020Mitochondria and their associated membranes actively participate in biosynthesis, trafficking, and degradation of cellular phospholipids. Two crucial lipid biosynthetic...
Mitochondria and their associated membranes actively participate in biosynthesis, trafficking, and degradation of cellular phospholipids. Two crucial lipid biosynthetic activities of mitochondria include (i) the decarboxylation of phosphatidylserine to phosphatidylethanolamine and (ii) the de novo synthesis of cardiolipin. Here we describe protocols to measure these two activities, applying isotope-labeled or exogenous substrates in combination with thin-layer chromatography or mass spectrometry.
Topics: Animals; Cardiolipins; Cells, Cultured; Drosophila melanogaster; Mitochondria; Phosphatidylethanolamines; Phosphatidylserines; Phospholipids
PubMed: 32183965
DOI: 10.1016/bs.mcb.2019.12.003 -
Food Chemistry Dec 2019The contents of N-acylphosphatidylethanolamines (NAPEs), N-acylethanolamines (NAEs) and endocannabinoids (ECs) in 43 food products were assessed and daily intakes, based...
The contents of N-acylphosphatidylethanolamines (NAPEs), N-acylethanolamines (NAEs) and endocannabinoids (ECs) in 43 food products were assessed and daily intakes, based on consumption of Mediterranean, vegetarian and Western diets, were simulated. NAPEs and NAEs were more abundant in plant-based foods than in animal food products; NAPEs were in the ranges 0-4032 vs 4-398 µg/g dw and NAEs were in the ranges 0-35 vs 0.1-0.7 µg/g dw, respectively while ECs were in the range 0-0.1 vs 0-34 µg/g dw. Daily intakes of NAPEs and NAEs were higher from Mediterranean (263 and 0.25 mg/day) and vegetarian (242 and 0.28 mg/day) diets than the Western diet (163 and 0.08 mg/day). Conversely, ECs intakes were higher from Western and Mediterranean diets (0.17 mg/day) than the vegetarian diet (0.01 mg/day). Future studies will evaluate the physiological role of dietary NAPEs, NAEs and ECs in humans.
Topics: Animals; Databases, Factual; Diet; Diet, Mediterranean; Diet, Vegetarian; Diet, Western; Endocannabinoids; Ethanolamines; Food Analysis; Phosphatidylethanolamines
PubMed: 31351254
DOI: 10.1016/j.foodchem.2019.125218 -
Nature May 2024Phosphatidylcholine and phosphatidylethanolamine, the two most abundant phospholipids in mammalian cells, are synthesized de novo by the Kennedy pathway from choline and...
Phosphatidylcholine and phosphatidylethanolamine, the two most abundant phospholipids in mammalian cells, are synthesized de novo by the Kennedy pathway from choline and ethanolamine, respectively. Despite the essential roles of these lipids, the mechanisms that enable the cellular uptake of choline and ethanolamine remain unknown. Here we show that the protein encoded by FLVCR1, whose mutation leads to the neurodegenerative syndrome posterior column ataxia and retinitis pigmentosa, transports extracellular choline and ethanolamine into cells for phosphorylation by downstream kinases to initiate the Kennedy pathway. Structures of FLVCR1 in the presence of choline and ethanolamine reveal that both metabolites bind to a common binding site comprising aromatic and polar residues. Despite binding to a common site, FLVCR1 interacts in different ways with the larger quaternary amine of choline in and with the primary amine of ethanolamine. Structure-guided mutagenesis identified residues that are crucial for the transport of ethanolamine, but dispensable for choline transport, enabling functional separation of the entry points into the two branches of the Kennedy pathway. Altogether, these studies reveal how FLVCR1 is a high-affinity metabolite transporter that serves as the common origin for phospholipid biosynthesis by two branches of the Kennedy pathway.
Topics: Humans; Binding Sites; Biological Transport; Choline; Ethanolamine; Membrane Transport Proteins; Models, Molecular; Phosphatidylcholines; Phosphatidylethanolamines; Phosphorylation; Mutagenesis
PubMed: 38693265
DOI: 10.1038/s41586-024-07374-4