The Importance of Glycerophospholipid Production to the Mutualist Symbiosis of Trypanosomatids

The symbiosis in trypanosomatids is a mutualistic relationship characterized by extensive metabolic exchanges between the bacterium and the protozoan. The symbiotic bacterium can complete host essential metabolic pathways, such as those for heme, amino acid, and vitamin production. Experimental assays indicate that the symbiont acquires phospholipids from the host trypanosomatid, especially phosphatidylcholine, which is often present in bacteria that have a close association with eukaryotic cells. In this work, an in-silico study was performed to find genes involved in the glycerophospholipid (GPL) production of Symbiont Harboring Trypanosomatids (SHTs) and their respective bacteria, also extending the search for trypanosomatids that naturally do not have symbionts. Results showed that most genes for GPL synthesis are only present in the SHT. The bacterium has an exclusive sequence related to phosphatidylglycerol production and contains genes for phosphatidic acid production, which may enhance SHT phosphatidic acid production. Phylogenetic data did not indicate gene transfers from the bacterium to the SHT nucleus, proposing that enzymes participating in GPL route have eukaryotic characteristics. Taken together, our data indicate that, differently from other metabolic pathways described so far, the symbiont contributes little to the production of GPLs and acquires most of these molecules from the SHT.

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Phosphatidylcholine Synthesis Influences the Diacylglycerol Homeostasis Required for Sec14p-dependent Golgi Function and Cell Growth

Molecular Biology of the Cell ◽

10.1091/mbc.12.3.511 ◽

2001 ◽

Vol 12 (3) ◽

pp. 511-520 ◽

Cited By ~ 48

Author(s):

Annette L. Henneberry ◽

Thomas A. Lagace ◽

Neale D. Ridgway ◽

Christopher R. McMaster

Keyword(s):

Cell Death ◽

Cell Growth ◽

Phosphatidic Acid ◽

Metabolic Pathways ◽

Eukaryotic Cells ◽

Kennedy Pathway ◽

Phosphatidylcholine Synthesis ◽

Long Chain

Phosphatidylcholine and phosphatidylethanolamine are the most abundant phospholipids in eukaryotic cells and thus have major roles in the formation and maintenance of vesicular membranes. In yeast, diacylglycerol accepts a phosphocholine moiety through aCPT1-derived cholinephosphotransferase activity to directly synthesize phosphatidylcholine. EPT1-derived activity can transfer either phosphocholine or phosphoethanolamine to diacylglcyerol in vitro, but is currently believed to primarily synthesize phosphatidylethanolamine in vivo. In this study we report that CPT1- and EPT1-derived cholinephosphotransferase activities can significantly overlap in vivo such that EPT1 can contribute to 60% of net phosphatidylcholine synthesis via the Kennedy pathway. Alterations in the level of diacylglycerol consumption through alterations in phosphatidylcholine synthesis directly correlated with the level of SEC14-dependent invertase secretion and affected cell viability. Administration of synthetic di8:0 diacylglycerol resulted in a partial rescue of cells fromSEC14-mediated cell death. The addition of di8:0 diacylglycerol increased di8:0 diacylglycerol levels 20–40-fold over endogenous long-chain diacylglycerol levels. Di8:0 diacylglcyerol did not alter endogenous phospholipid metabolic pathways, nor was it converted to di8:0 phosphatidic acid.

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Faculty Opinions recommendation of Non-racemic amino acid production by ultraviolet irradiation of achiral interstellar ice analogs with circularly polarized light.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.8329957.8916055 ◽

2011 ◽

Author(s):

Niles Lehman ◽

Aaron Burton

Keyword(s):

Amino Acid ◽

Ultraviolet Irradiation ◽

Acid Production ◽

Polarized Light ◽

Amino Acid Production ◽

Circularly Polarized Light ◽

Circularly Polarized ◽

Interstellar Ice ◽

Racemic Amino Acid

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Itaconate Alters Succinate and Coenzyme A Metabolism via Inhibition of Mitochondrial Complex II and Methylmalonyl-CoA Mutase

Metabolites ◽

10.3390/metabo11020117 ◽

2021 ◽

Vol 11 (2) ◽

pp. 117

Author(s):

Thekla Cordes ◽

Christian M. Metallo

Keyword(s):

Amino Acid ◽

Metabolic Pathways ◽

Mammalian Cells ◽

Coenzyme A ◽

Cultured Cells ◽

Tca Cycle ◽

Regulatory Function ◽

Reversible Inhibitor ◽

Complex Ii ◽

Branched Chain

Itaconate is a small molecule metabolite that is endogenously produced by cis-aconitate decarboxylase-1 (ACOD1) in mammalian cells and influences numerous cellular processes. The metabolic consequences of itaconate in cells are diverse and contribute to its regulatory function. Here, we have applied isotope tracing and mass spectrometry approaches to explore how itaconate impacts various metabolic pathways in cultured cells. Itaconate is a competitive and reversible inhibitor of Complex II/succinate dehydrogenase (SDH) that alters tricarboxylic acid (TCA) cycle metabolism leading to succinate accumulation. Upon activation with coenzyme A (CoA), itaconyl-CoA inhibits adenosylcobalamin-mediated methylmalonyl-CoA (MUT) activity and, thus, indirectly impacts branched-chain amino acid (BCAA) metabolism and fatty acid diversity. Itaconate, therefore, alters the balance of CoA species in mitochondria through its impacts on TCA, amino acid, vitamin B12, and CoA metabolism. Our results highlight the diverse metabolic pathways regulated by itaconate and provide a roadmap to link these metabolites to potential downstream biological functions.

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Comprehensive transcriptome and metabolome profiling reveal metabolic mechanisms of Nitraria sibirica Pall. to salt stress

Scientific Reports ◽

10.1038/s41598-021-92317-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Huanyong Li ◽

Xiaoqian Tang ◽

Xiuyan Yang ◽

Huaxin Zhang

Keyword(s):

Salt Stress ◽

Amino Acid ◽

Salt Tolerance ◽

Metabolic Pathways ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Sulfur Metabolism ◽

Enrichment Analysis ◽

Extracellular Region ◽

Nitraria Sibirica

AbstractNitraria sibirica Pall., a typical halophyte that can survive under extreme drought conditions and in saline-alkali environments, exhibits strong salt tolerance and environmental adaptability. Understanding the mechanism of molecular and physiological metabolic response to salt stress of plant will better promote the cultivation and use of halophytes. To explore the mechanism of molecular and physiological metabolic of N. sibirica response to salt stress, two-month-old seedlings were treated with 0, 100, and 400 mM NaCl. The results showed that the differentially expressed genes between 100 and 400 mmol L−1 NaCl and unsalted treatment showed significant enrichment in GO terms such as binding, cell wall, extemal encapsulating structure, extracellular region and nucleotide binding. KEGG enrichment analysis found that NaCl treatment had a significant effect on the metabolic pathways in N. sibirica leaves, which mainly including plant-pathogen interaction, amino acid metabolism of the beta alanine, arginine, proline and glycine metabolism, carbon metabolism of glycolysis, gluconeogenesis, galactose, starch and sucrose metabolism, plant hormone signal transduction and spliceosome. Metabolomics analysis found that the differential metabolites between the unsalted treatment and the NaCl treatment are mainly amino acids (proline, aspartic acid, methionine, etc.), organic acids (oxaloacetic acid, fumaric acid, nicotinic acid, etc.) and polyhydric alcohols (inositol, ribitol, etc.), etc. KEGG annotation and enrichment analysis showed that 100 mmol L−1 NaCl treatment had a greater effect on the sulfur metabolism, cysteine and methionine metabolism in N. sibirica leaves, while various amino acid metabolism, TCA cycle, photosynthetic carbon fixation and sulfur metabolism and other metabolic pathways have been significantly affected by 400 mmol L−1 NaCl treatment. Correlation analysis of differential genes in transcriptome and differential metabolites in metabolome have found that the genes of AMY2, BAM1, GPAT3, ASP1, CML38 and RPL4 and the metabolites of L-cysteine, proline, 4-aminobutyric acid and oxaloacetate played an important role in N. sibirica salt tolerance control. This is a further improvement of the salt tolerance mechanism of N. sibirica, and it will provide a theoretical basis and technical support for treatment of saline-alkali soil and the cultivation of halophytes.

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