scholarly journals Synthesis of Dolichols in Candida albicans Is Co-Regulated with Elongation of Fatty Acids

2021 ◽  
Vol 23 (1) ◽  
pp. 409
Author(s):  
Anna Janik ◽  
Urszula Perlińska-Lenart ◽  
Katarzyna Gawarecka ◽  
Justyna Augustyniak ◽  
Ewelina Bratek-Gerej ◽  
...  

Protein glycosylation requires dolichyl phosphate as a carbohydrate carrier. Dolichols are α-saturated polyprenols, and their saturation in S. cerevisiae is catalyzed by polyprenyl reductase Dfg10 together with some other unknown enzymes. The aim of this study was to identify such enzymes in Candida. The Dfg10 polyprenyl reductase from S. cerevisiae comprises a C-terminal 3-oxo-5-alpha-steroid 4-dehydrogenase domain. Alignment analysis revealed such a domain in two ORFs (orf19.209 and orf19.3293) from C. albicans, which were similar, respectively, to Dfg10 polyprenyl reductase and Tsc13 enoyl-transferase from S. cerevisiae. Deletion of orf19.209 in Candida impaired saturation of polyprenols. The Tsc13 homologue turned out not to be capable of saturating polyprenols, but limiting its expression reduce the cellular level of dolichols and polyprenols. This reduction was not due to a decreased expression of genes encoding cis-prenyltransferases from the dolichol branch but to a lower expression of genes encoding enzymes of the early stages of the mevalonate pathway. Despite the resulting lower consumption of acetyl-CoA, the sole precursor of the mevalonate pathway, it was not redirected towards fatty acid synthesis or elongation. Lowering the expression of TSC13 decreased the expression of the ACC1 gene encoding acetyl-CoA carboxylase, the key regulatory enzyme of fatty acid synthesis and elongation.

2004 ◽  
Vol 279 (21) ◽  
pp. 21779-21786 ◽  
Author(s):  
Ursula Hoja ◽  
Sandra Marthol ◽  
Jörg Hofmann ◽  
Sabine Stegner ◽  
Rainer Schulz ◽  
...  

1987 ◽  
Vol 243 (2) ◽  
pp. 437-442 ◽  
Author(s):  
M G Buckley ◽  
E A Rath

1. The effect of nutritional status on fatty acid synthesis in brown adipose tissue was compared with the effect of cold-exposure. Fatty acid synthesis was measured in vivo by 3H2O incorporation into tissue lipids. The activities of acetyl-CoA carboxylase and fatty acid synthetase and the tissue concentrations of malonyl-CoA and citrate were assayed. 2. In brown adipose tissue of control mice, the tissue content of malonyl-CoA was 13 nmol/g wet wt., higher than values reported in other tissues. From the total tissue water content, the minimum possible concentration was estimated to be 30 microM 3. There were parallel changes in fatty acid synthesis, malonyl-CoA content and acetyl-CoA carboxylase activity in response to starvation and re-feeding. 4. There was no correlation between measured rates of fatty acid synthesis and malonyl-CoA content and acetyl-CoA carboxylase activity in acute cold-exposure. The results suggest there is simultaneous fatty acid synthesis and oxidation in brown adipose tissue of cold-exposed mice. This is probably effected not by decreases in the malonyl-CoA content, but by increases in the concentration of free long-chain fatty acyl-CoA or enhanced peroxisomal oxidation, allowing shorter-chain fatty acids to enter the mitochondria independent of carnitine acyltransferase (overt form) activity.


2019 ◽  
Vol 196 ◽  
pp. 69-80 ◽  
Author(s):  
Tomas Erban ◽  
Bruno Sopko ◽  
Pavel Talacko ◽  
Karel Harant ◽  
Klara Kadlikova ◽  
...  

2000 ◽  
Vol 28 (6) ◽  
pp. 567-574 ◽  
Author(s):  
J. Ohlrogge ◽  
M. Pollard ◽  
X. Bao ◽  
M. Focke ◽  
T. Girke ◽  
...  

For over 25 years there has been uncertainty over the pathway from CO2, to acetyl-CoA in chloroplasts. On the one hand, free acetate is the most effective substrate for fatty acid synthesis by isolated chloroplasts, and free acetate concentrations reported in leaf tissue (0.1–1 mM) appear adequate to saturate fatty acid synthase. On the other hand, a clear mechanism to generate sufficient free acetate for fatty acid synthesis is not established and direct production of acetyl-CoA from pyruvate by a plastid pyruvate dehydrogenase seems a more simple and direct path. We have re-examined this question and attempted to distinguish between the alternatives. The kinetics of 13CO2 and 14CO2 movement into fatty acids and the absolute rate of fatty acid synthesis in leaves was determined in light and dark. Because administered 14C appears in fatty acids within < 2–3 min our results are inconsistent with a large pool of free acetate as an intermediate in leaf fatty acid synthesis. In addition, these studies provide an estimate of the turnover rate of fatty acid in leaves. Studies similar to the above are more complex in seeds, and some questions about the regulation of plant lipid metabolism seem difficult to solve using conventional biochemical or molecular approaches. For example, we have little understanding of why or how some seeds produce >50%, oil whereas other seeds store largely carbohydrate or protein. Major control over complex plant biochemical pathways may only become possible by understanding regulatory networks which provide ‘global’ control over these pathways. To begin to discover such networks and provide a broad analysis of gene expression in developing oilseeds, we have produced micro-arrays that display approx. 5000 seed-expressed Arabidopsis genes. Sensitivity of the arrays was 1–2 copies of mRNA/cell. The arrays have been hybridized with probes derived from seeds, leaves and roots, and analysis of expression ratios between the different tissues has allowed the tissue-specific expression patterns of many hundreds of genes to be described for the first time. Approx. 10% of the genes were expressed at ratios ≥ 10-fold higher in seeds than in leaves or roots. Included in this list are a large number of proteins of unknown function, and potential regulatory factors such as protein kinases, phosphatases and transcription factors. The arrays were also found to be useful for analysis of Brassica seeds.


2004 ◽  
Vol 279 (41) ◽  
pp. 43217-43226 ◽  
Author(s):  
Ilya R. Bederman ◽  
Takhar Kasumov ◽  
Aneta E. Reszko ◽  
France David ◽  
Henri Brunengraber ◽  
...  

2010 ◽  
Vol 4 ◽  
pp. BBI.S4168 ◽  
Author(s):  
Sandeep J. Joseph ◽  
Kelly R. Robbins ◽  
Enrique Pavan ◽  
Scott L. Pratt ◽  
Susan K. Duckett ◽  
...  

Conjugated linoleic acids (CLA) are of important nutritional and health benefit to human. Food products of animal origin are their major dietary source and their concentration increases with high concentrate diets fed to animals. To examine the effects of diet supplementation on the expression of genes related to lipid metabolism, 28 Angus steers were fed either pasture only, pasture with soybean hulls and corn oil, pasture with corn grain, or high concentrate diet. At slaughter, samples of subcutaneous adipose tissue were collected, from which RNA was extracted. Relative abundance of gene expression was measured using Affymetrix GeneChip Bovine Genome array. An ANOVA model nested within gene was used to analyze the background adjusted, normalized average difference of probe-level intensities. To control experiment wise error, a false discovery rate of 0.01 was imposed on all contrasts. Expression of several genes involved in the synthesis of enzymes related to fatty acid metabolism and lipogenesis such as stearoyl-CoA desaturase (SCD), fatty acid synthetase (FASN), lipoprotein lipase (LPL), fatty-acyl elongase (LCE) along with several trancription factors and co-activators involved in lipogenesis were found to be differentially expressed. Confirmatory RT-qPCR was done to validate the microarray results, which showed satisfactory correspondence between the two platforms. Results show that changes in diet by increasing dietary energy intake by supplementing high concentrate diet have effects on the transcription of genes encoding enzymes involved in fat metabolism which in turn has effects on fatty acid content in the carcass tissue as well as carcass quality. Corn supplementation either as oil or grain appeared to significantly alter the expression of genes directly associated with fatty acid synthesis.


2020 ◽  
Vol 104 (14) ◽  
pp. 6057-6065 ◽  
Author(s):  
Lars Milke ◽  
Jan Marienhagen

AbstractMalonyl-CoA is an important central metabolite serving as the basic building block for the microbial synthesis of many pharmaceutically interesting polyketides, but also fatty acid–derived compounds including biofuels. Especially Saccharomyces cerevisiae, Escherichia coli, and Corynebacterium glutamicum have been engineered towards microbial synthesis of such compounds in recent years. However, developed strains and processes often suffer from insufficient productivity. Usually, tightly regulated intracellular malonyl-CoA availability is regarded as the decisive bottleneck limiting overall product formation. Therefore, metabolic engineering towards improved malonyl-CoA availability is essential to design efficient microbial cell factories for the production of polyketides and fatty acid derivatives. This review article summarizes metabolic engineering strategies to improve intracellular malonyl-CoA formation in industrially relevant microorganisms and its impact on productivity and product range, with a focus on polyketides and other malonyl-CoA-dependent products.Key Points• Malonyl-CoA is the central building block of polyketide synthesis.• Increasing acetyl-CoA supply is pivotal to improve malonyl-CoA availability.• Improved acetyl-CoA carboxylase activity increases availability of malonyl-CoA.• Fatty acid synthesis as an ambivalent target to improve malonyl-CoA supply.


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