scholarly journals Features of psychrophilic and thermophilic methanotrophic microorganisms

2020 ◽  
Author(s):  
М.С. БАКУНИНА ◽  
А.Л. ПОНОМАРЕВА ◽  
С.С. ДУБОВЧУК ◽  
А.И. . ЕСЬКОВА ◽  
Р.Б. ШАКИРОВ ◽  
...  
Keyword(s):  
Fatty Acids ◽  
High Temperatures ◽  
Methane Monooxygenase ◽  
Type I ◽  
Type Ii ◽  
Ribulose Monophosphate Pathway ◽  
Biochemical Features

Обзор посвящен описанию структурно-функциональных и физиолого-биохимических особенностей метанотрофов, обитающих в экотопах с низкими и высокими температурами. Показано, что в холодных экосистемах обитают метанотрофы I типа, для которых характерны ассимиляция углерода по рибулозомонофосфатному пути, преобладание жирных кислот с 16 атомами углерода, мембранная форма метанмонооксигеназы (ММО). Среди термофилов доминируют метанотрофы II типа, которым свойственны наличие как растворимой, так и мембранной формы ММО, реализация, наряду с РМФ циклом, минорных серинового и РБФ путей Сі-ассимиляции. This paper considers some structural-functional and physiological-biochemical features of methanotrophs living in ecotopes with low and high temperatures. It has been established that cold ecosystems are characterized by type I methanotrophs, with the assimilation of carbon along the ribulose monophosphate pathway, the predominance of fatty acids with 16 carbon atoms, and the presence of membrane methane monooxygenase (MMO). Representatives of both types are detected among thermophilic methanotrophs, but type II with the presence of soluble and membrane forms of MMO is dominant, where, along with the RMF cycle, minor serine and RBF Ci-assimilation pathways are realized.

scholarly journals Comprehensive Characterization of Toxoplasma Acyl Coenzyme A-Binding Protein TgACBP2 and Its Critical Role in Parasite Cardiolipin Metabolism

mBio ◽  
2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Yong Fu ◽  
Xia Cui ◽  
Sai Fan ◽  
Jing Liu ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Toxoplasma Gondii ◽  
Binding Protein ◽  
Ankyrin Repeat ◽  
Type I ◽  
Type Ii ◽  
Content Type ◽  
High K ◽  
Acyl Coenzyme A

ABSTRACT Acyl coenzyme A (CoA)-binding protein (ACBP) can bind acyl-CoAs with high specificity and affinity, thus playing multiple roles in cellular functions. Mitochondria of the apicomplexan parasite Toxoplasma gondii have emerged as key organelles for lipid metabolism and signaling transduction. However, the rationale for how this parasite utilizes acyl-CoA-binding protein to regulate mitochondrial lipid metabolism remains unclear. Here, we show that an ankyrin repeat-containing protein, TgACBP2, is localized to mitochondria and displays active acyl-CoA-binding activities. Dephosphorylation of TgACBP2 is associated with relocation from the plasma membrane to the mitochondria under conditions of regulation of environmental [K+]. Under high [K+] conditions, loss of ACBP2 induced mitochondrial dysfunction and apoptosis-like cell death. Disruption of ACBP2 caused growth and virulence defects in the type II strain but not in type I parasites. Interestingly, mitochondrial association factor-1 (MAF1)-mediated host mitochondrial association (HMA) restored the growth ability of ACBP2-deficient type II parasites. Lipidomics analysis indicated that ACBP2 plays key roles in the cardiolipin metabolism of type II parasites and that MAF1 expression complemented the lipid metabolism defects of ACBP2-deficient type II parasites. In addition, disruption of ACBP2 caused attenuated virulence of Prugniuad (Pru) parasites for mice. Taking the results collectively, these data indicate that ACBP2 is critical for the growth and virulence of type II parasites and for the growth of type I parasites under high [K+] conditions. IMPORTANCE Toxoplasma gondii is one of the most successful human parasites, infecting nearly one-third of the total world population. T. gondii tachyzoites residing within parasitophorous vacuoles (PVs) can acquire fatty acids both via salvage from host cells and via de novo synthesis pathways for membrane biogenesis. However, although fatty acid fluxes are known to exist in this parasite, how fatty acids flow through Toxoplasma lipid metabolic organelles, especially mitochondria, remains unknown. In this study, we demonstrated that Toxoplasma expresses an active ankyrin repeat containing protein TgACBP2 to coordinate cardiolipin metabolism. Specifically, HMA acquisition resulting from heterologous functional expression of MAF1 rescued growth and lipid metabolism defects in ACBP2-deficient type II parasites, manifesting the complementary role of host mitochondria in parasite cardiolipin metabolism. This work highlights the importance of TgACBP2 in parasite cardiolipin metabolism and provides evidence for metabolic association of host mitochondria with T. gondii.

scholarly journals Characterization and Biosynthesis of Lipids in Paulinella micropora MYN1: Evidence for Efficient Integration of Chromatophores into Cellular Lipid Metabolism

2020 ◽  
Vol 61 (5) ◽  
pp. 869-881 ◽  
Author(s):  
Naoki Sato ◽  
Toru Yoshitomi ◽  
Natsumi Mori-Moriyama
Keyword(s):  
Fatty Acids ◽  
Marine Algae ◽  
Type I ◽  
Type Ii ◽  
Cellular Lipid ◽  
Animal Cells ◽  
Fixed Carbon ◽  
Ultrastructural Evidence ◽  
Efficient Integration ◽  
Rapid Labeling

Abstract The chromatophores found in the cells of photosynthetic Paulinella species, once believed to be endosymbiotic cyanobacteria, are photosynthetic organelles that are distinct from chloroplasts. The chromatophore genome is similar to the genomes of α-cyanobacteria and encodes about 1,000 genes. Therefore, the chromatophore is an intriguing model of organelle formation. In this study, we analyzed the lipids of Paulinella micropora MYN1 to verify that this organism is a composite of cyanobacterial descendants and a heterotrophic protist. We detected glycolipids and phospholipids, as well as a betaine lipid diacylglyceryl-3-O-carboxyhydroxymethylcholine, previously detected in many marine algae. Cholesterol was the only sterol component detected, suggesting that the host cell is similar to animal cells. The glycolipids, presumably present in the chromatophores, contained mainly C16 fatty acids, whereas other classes of lipids, presumably present in the other compartments, were abundant in C20 and C22 polyunsaturated fatty acids. This suggests that chromatophores are metabolically distinct from the rest of the cell. Metabolic studies using isotopically labeled substrates showed that different fatty acids are synthesized in the chromatophore and the cytosol, which is consistent with the presence of both type I and type II fatty acid synthases, supposedly present in the cytosol and the chromatophore, respectively. Nevertheless, rapid labeling of the fatty acids in triacylglycerol and phosphatidylcholine by photosynthetically fixed carbon suggested that the chromatophores efficiently provide metabolites to the host. The metabolic and ultrastructural evidence suggests that chromatophores are tightly integrated into the whole cellular metabolism.

scholarly journals Mitochondrial Fatty Acid Synthesis in Trypanosoma brucei

2006 ◽  
Vol 282 (7) ◽  
pp. 4427-4436 ◽  
Author(s):  
Jennifer L. Stephens ◽  
Soo Hee Lee ◽  
Kimberly S. Paul ◽  
Paul T. Englund
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Trypanosoma Brucei ◽  
Lipoic Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Type I ◽  
Type Ii ◽  
Acetyl Coa ◽  
Acid Product

Whereas other organisms utilize type I or type II synthases to make fatty acids, trypanosomatid parasites such as Trypanosoma brucei are unique in their use of a microsomal elongase pathway (ELO) for de novo fatty acid synthesis (FAS). Because of the unusual lipid metabolism of the trypanosome, it was important to study a second FAS pathway predicted by the genome to be a type II synthase. We localized this pathway to the mitochondrion, and RNA interference (RNAi) or genomic deletion of acyl carrier protein (ACP) and β-ketoacyl-ACP synthase indicated that this pathway is likely essential for bloodstream and procyclic life cycle stages of the parasite. In vitro assays show that the largest major fatty acid product of the pathway is C16, whereas the ELO pathway, utilizing ELOs 1, 2, and 3, synthesizes up to C18. To demonstrate mitochondrial FAS in vivo, we radio-labeled fatty acids in cultured procyclic parasites with [14C]pyruvate or [14C]threonine, either of which is catabolized to [14C]acetyl-CoA in the mitochondrion. Although some of the [14C]acetyl-CoA may be utilized by the ELO pathway, a striking reduction in radiolabeled fatty acids following ACP RNAi confirmed that it is also consumed by mitochondrial FAS. ACP depletion by RNAi or gene knockout also reduces lipoic acid levels and drastically decreases protein lipoylation. Thus, octanoate (C8), the precursor for lipoic acid synthesis, must also be a product of mitochondrial FAS. Trypanosomes employ two FAS systems: the unconventional ELO pathway that synthesizes bulk fatty acids and a mitochondrial pathway that synthesizes specialized fatty acids that are likely utilized intramitochondrially.

71 The Use of Medium Chain Fatty Acids to Reduce Porcine Reproductive Respiratory Syndrome Virus Replication in MARC-145 Cells

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 35-36
Author(s):  
Stacie Crowder ◽  
Roman Pogranichniy ◽  
Brenda DeRodas ◽  
Karnezos Peter ◽  
J S S Radcliffe
Keyword(s):  
Fatty Acids ◽  
Viral Replication ◽  
Respiratory Syndrome Virus ◽  
Type I ◽  
Type Ii ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Log Reduction ◽  
Virus Strains ◽  
Chain Fatty Acids

Abstract Porcine reproductive respiratory syndrome virus (PPRSV) costs the U.S. Swine Industry an estimated $664 million annually. The objective of this study was to evaluate the effect of medium chain fatty acids (MCFA) on PRRSV replication in M-145 cells. Two experiments were conducted to 1) evaluate the use of individual MCFAs (C6, C8, C10), and 2) evaluate MCFA combinations (C8/C10, C10/C12, C8/C10/C12) on viral replication of PRRSV. Experiment one used individual MCFAs at 7 concentrations from 1-1000µg/ml compared to a control. Experiment two used MCFA combinations at 6 different concentrations from 50–500µg/ml compared to a control. North American Type II P-129 PRRSV and European Type I Lelystad PRRSV strains were used. Viral replication was determined using FITC labeled IgG anti-PRRSV monoclonal antibody and TCID50 was calculated for each treatment concentration using 5 wells per treatment at each virus concentration with plates run in triplicate. Data were analyzed using Proc Mixed procedures of SAS. In experiment 1, C6 had no effect on replication of PRRSV in M145 cells. C8 induced a 3.02 and 2.02 log reduction in TCID50 for type I and type II virus strains, respectively (P < 0.01) at 1000µg/ml. C10 induced a 2.85 and 3.23 log reduction in TCID50 for type I and type II virus strains, respectively (P < 0.01) at 300µg/ml. In experiment 2, C8/C10 induced a 1.9 and 2.2 log reduction in TCID50 for type I and type II virus strains, respectively (P < 0.01) at 200µg/ml. C10/C12 resulted in a 3.37 and 2.14 log reduction in TCID50 at 200µg/ml for type I and type II virus strains, respectively (P < 0.01). C8/C10/C12 resulted in a 1.34 and 1.56 log reduction in TCID50 at 200µg/ml for type I and type II virus strains (P < 0.01), respectively.

scholarly journals Methylothermus thermalis gen. nov., sp. nov., a novel moderately thermophilic obligate methanotroph from a hot spring in Japan

2005 ◽  
Vol 55 (5) ◽  
pp. 1877-1884 ◽  
Author(s):  
Jun Tsubota ◽  
Bulat Ts. Eshinimaev ◽  
Valentina N. Khmelenina ◽  
Yuri A. Trotsenko
Keyword(s):  
Sequence Analysis ◽  
Hot Spring ◽  
Methane Monooxygenase ◽  
Comparative Sequence Analysis ◽  
Rrna Gene ◽  
Type I ◽  
Particulate Methane Monooxygenase ◽  
Moderately Thermophilic ◽  
Ribulose Monophosphate Pathway ◽  
Genotypic Characteristics

A novel moderately thermophilic methanotroph, strain MYHTT, was isolated from a hot spring in Japan. The isolate grew on methane or methanol at 37–67 °C, and optimally at 57–59 °C. It was found to be a Gram-negative aerobe, with colourless colonies of non-motile coccoid cells, possessing type I intracytoplasmic membranes and regularly arranged surface layers of linear (p2) symmetry. Strain MYHTT expressed only the particulate methane monooxygenase and employed the ribulose monophosphate pathway for formaldehyde assimilation. It is a neutrophilic and halotolerant organism capable of growth at pH 6·5–7·5 (optimum pH 6·8) and in up to 3 % NaCl (optimum 0·5–1 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequence analysis indicated that strain MYHTT is most closely related to the thermophilic undescribed methanotroph ‘Methylothermus’ HB (91 % identity) and the novel halophilic methanotroph Methylohalobius crimeensis 10KiT (90 % identity). Comparative sequence analysis of particulate methane monooxygenase (pmoA) genes also confirmed the clustering of strain MYHTT with ‘Methylothermus’ HB and Methylohalobius crimeensis 10KiT (98 and 92 % derived amino acid sequence identity, respectively). The DNA G+C content was 62·5 mol%. The major cellular fatty acids were C16 : 0 (37·2 %) and C18 : 1 ω9c (35·2 %) and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The major ubiquinone was Q-8. On the basis of comparative phenotypic and genotypic characteristics, a new genus and species, Methylothermus thermalis gen. nov., sp. nov., is proposed, with MYHTT as the type strain (=VKM B-2345T=IPOD FERM P-19714T).

scholarly journals BP180/Collagen XVII: A Molecular View

2021 ◽  
Vol 22 (22) ◽  
pp. 12233
Author(s):  
Jussi Tuusa ◽  
Nina Kokkonen ◽  
Kaisa Tasanen
Keyword(s):  
Cell Proliferation ◽  
Protein Interactions ◽  
Transmembrane Protein ◽  
Epidermal Keratinocytes ◽  
Central Component ◽  
Type I ◽  
Type Ii ◽  
Protein Protein Interactions ◽  
Collagen Xvii ◽  
Biochemical Features

BP180 is a type II collagenous transmembrane protein and is best known as the major autoantigen in the blistering skin disease bullous pemphigoid (BP). The BP180 trimer is a central component in type I hemidesmosomes (HD), which cause the adhesion between epidermal keratinocytes and the basal lamina, but BP180 is also expressed in several non-HD locations, where its functions are poorly characterized. The immunological roles of intact and proteolytically processed BP180, relevant in BP, have been subject to intensive research, but novel functions in cell proliferation, differentiation, and aging have also recently been described. To better understand the multiple physiological functions of BP180, the focus should return to the protein itself. Here, we comprehensively review the properties of the BP180 molecule, present new data on the biochemical features of its intracellular domain, and discuss their significance with regard to BP180 folding and protein–protein interactions.

scholarly journals Radioactive Fingerprinting of Microorganisms That Oxidize Atmospheric Methane in Different Soils

1999 ◽  
Vol 65 (9) ◽  
pp. 4064-4070 ◽  
Author(s):  
Peter Roslev ◽  
Niels Iversen
Keyword(s):  
Fatty Acids ◽  
The United States ◽  
Type I ◽  
Methanotrophic Bacteria ◽  
Type Ii ◽  
Atmospheric Methane ◽  
Tropical Regions ◽  
Methane Metabolism ◽  
Conversion Efficiencies ◽  
Different Soils

ABSTRACT Microorganisms that oxidize atmospheric methane in soils were characterized by radioactive labelling with14CH4 followed by analysis of radiolabelled phospholipid ester-linked fatty acids (14C-PLFAs). The radioactive fingerprinting technique was used to compare active methanotrophs in soil samples from Greenland, Denmark, the United States, and Brazil. The 14C-PLFA fingerprints indicated that closely related methanotrophic bacteria were responsible for the oxidation of atmospheric methane in the soils. Significant amounts of labelled PLFAs produced by the unknown soil methanotrophs coeluted with a group of fatty acids that included i17:0, a17:0, and 17:1ω8c (up to 9.0% of the total 14C-PLFAs). These PLFAs are not known to be significant constituents of methanotrophic bacteria. The major PLFAs of the soil methanotrophs (73.5 to 89.0% of the total PLFAs) coeluted with 18:1 and 18:0 fatty acids (e.g., 18:1ω9, 18:1ω7, and 18:0). The 14C-PLFAs fingerprints of the soil methanotrophs that oxidized atmospheric methane did not change after long-term methane enrichment at 170 ppm CH4. The 14C-PLFA fingerprints of the soil methanotrophs were different from the PLFA profiles of type I and type II methanotrophic bacteria described previously. Some similarity at the PLFA level was observed between the unknown soil methanotrophs and the PLFA phenotype of the type II methanotrophs. Methanotrophs in Arctic, temperate, and tropical regions assimilated between 20 and 54% of the atmospheric methane that was metabolized. The lowest relative assimilation (percent) was observed for methanotrophs in agricultural soil, whereas the highest assimilation was observed for methanotrophs in rain forest soil. The results suggest that methanotrophs with relatively high carbon conversion efficiencies and very similar PLFA compositions dominate atmospheric methane metabolism in different soils. The characteristics of the methane metabolism and the 14C-PLFA fingerprints excluded any significant role of autotrophic ammonia oxidizers in the metabolism of atmospheric methane.

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