scholarly journals Draft genome of the liver fluke Fasciola gigantica

2018 ◽  
Author(s):  
Tripti Tripathi ◽  
Arpita Ghosh ◽  
Vivek N Todur ◽  
Parismita Kalita ◽  
R Vijayakumar ◽  
...  

ABSTRACTFascioliasis is a neglected food-borne disease caused by liver flukes (genus Fasciola) and affects more than 200 million people worldwide. Despite technological advances, little is known about the molecular biology and biochemistry of the fluke. We present the draft genome of Fasciola gigantica for the first time. The assembled draft genome has a size of ~1.04 Gb with an N50 of 129 kb. A total of 20,858 genes were predicted. The de novo repeats identified in the draft genome were 46.85%. In pathway analysis, all the genes of glycolysis, Kreb’s cycle and fatty acid metabolism were found to be present, but the key genes for fatty acid production in fatty acid biosynthesis were missing. This indicates that the fatty acid required for the survival of the fluke may be acquired from the host bile. The genomic information will provide a comprehensive resource to facilitate the development of novel interventions for fascioliasis control.

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 42
Author(s):  
Ni An ◽  
Jianyuan Zhao ◽  
Shan Cen

Human SAMHD1 is an IFN-induced dNTP triphosphatase that is able to restrict HIV-1 replication, whereas its role in innate immunity against virus infection remains largely unexplored. In this work, we provided evidence that SAMHD1 functions as an anti-HCV host factor. We found that overexpression of SAMHD1 resulted in significant inhibition on the replication of HCV, but not other RNA viruses including influenza A virus and EV71. SAMHD1 knockdown partially relieved the inhibitory effect of IFN on HCV, suggesting its important role in the innate immune response against HCV. Mechanistic studies revealed that SAMHD1 targets viral RNA replication without impact on both protein translation and virus entry. Transcriptome analysis showed a broad inhibitory effect of SAMHD1 on host genes involved in cholesterol and fatty acid biosynthesis. In particular, SAMHD1 was shown to downregulate the mRNA abundance of SREBP1, a master transcriptional regulator of de novo lipid biosynthesis, impairing the formation of lipid droplets. Restoring intracellular lipid levels by either exogenous lipid addition or SREBP1 overexpression counteracted the restriction of HCV by SAMHD1, providing evidence that SAMHD1 inhibits the replication of HCV by suppressing host cholesterol and fatty acid biosynthesis. Together, these data unveil, for the first time, a novel antiviral mechanism of SAMHD1 and open new avenues for the development of novel anti-HCV therapeutics.


1991 ◽  
Vol 81 (2) ◽  
pp. 251-255
Author(s):  
Manfred Focke ◽  
Andrea Feld ◽  
Hartmut K. Lichtenthaler

1992 ◽  
Vol 47 (5-6) ◽  
pp. 382-386 ◽  
Author(s):  
Bernd List ◽  
Andrea Golz ◽  
Wilhelm Boland ◽  
Hartmut K. Lichtenthaler

The antibiotic cerulenin was shown to be a potent dose-dependent inhibitor of de novo fattyacid biosynthesis in intact isolated chloroplasts of different plants (measured as [14C]acetate incorporation into the total fatty-acid fraction). Various chemical derivatives of cerulenin were synthesized and tested in the chloroplast assay-system of oat, spinach and pea. Modifications of the hydrocarbon chain of cerulenin (e.g. tetrahydro-cerulenin and its short-chain cis-2,3-epoxy-4-oxoheptanamide derivative) decreased the inhibitory activity of cerulenin, whereas variations of the epoxy-oxo-amide structural element led to a complete loss of inhibition potency. The results indicate that the naturally occurring antibiotic cerulenin is the most active specific inhibitor of de novo fatty-acid biosynthesis, but the formation of the hydroxylactam ring seems to be an essential requirement for the inhibitory activity. Those structural analogues of cerulenin, which can no longer form a hydroxylactam ring, do not possess any inhibitory capacity.


1963 ◽  
Vol 41 (1) ◽  
pp. 1267-1274
Author(s):  
Peter F. Hall ◽  
Edward E. Nishizawa ◽  
Kristen B. Eik-Nes

The fatty acids palmitic, palmitoleic, stearic, and oleic have been isolated from rabbit testis and evidence for the synthesis of palmitic and stearic acids de novo from acetate-1-C14is presented. ICSH did not produce demonstrable stimulation of the synthesis of these acids in vitro although the hormone stimulated the production of testosterone-C14by the same tissue. Adrenal tissue was shown to contain palmitic, stearic, and oleic acids, and ACTH did not increase the incorporation of acetate-1-C14into a fatty acid fraction extracted following incubation of adrenal tissue in the presence of this substrate. Fatty acid biosynthesis, therefore, is probably not influenced by the mechanisms by which tropic hormones increase steroid formation.


1994 ◽  
Vol 267 (2) ◽  
pp. L128-L136
Author(s):  
J. Rami ◽  
W. Stenzel ◽  
S. M. Sasic ◽  
C. Puel-M'Rini ◽  
J. P. Besombes ◽  
...  

Silica instillation causes a massive increase in lung surfactant. Two populations of type II pneumocytes can be isolated from rats administered silica by intratracheal injection: type IIA cells similar to type II cells from normal rats and type IIB cells, which are larger and contain elevated levels of surfactant protein A and phospholipid. Activities of choline-phosphate cytidylyltransferase, a rate-regulatory enzyme in phosphatidylcholine biosynthesis, and fatty-acid synthase (FAS) are increased in type IIB cells isolated from rats 14 days after silica injection. In the present study, we examined the increase in FAS and cytidylyltransferase activities in type IIB cells as a function of time after silica administration. FAS activity increased rapidly, was approximately threefold elevated 1 day after silica administration and has reached close to the maximum increase by 3 days. Cytidylyltransferase activity was not increased on day 1, was significantly increased on day 3 but was not maximally increased until day 7. Inhibition of de novo fatty-acid biosynthesis, by in vivo injection of hydroxycitric acid and inclusion of agaric acid in the type II cell culture medium, abolished the increase in cytidylyltransferase activity on day 3 but not FAS and had no effect on activities of two other enzymes of phospholipid synthesis. FAS mRNA levels were not increased in type IIB cells isolated 1-14 days after silica injection. These data show that the increase in FAS activity in type IIB cells is an early response to silica, that it mediates the increase in cytidylyltransferase activity, and that it is not due to enhanced FAS gene expression.


1990 ◽  
Vol 45 (5) ◽  
pp. 518-520 ◽  
Author(s):  
Manfred Focke ◽  
Andrea Feld ◽  
Hartmut K. Lichtenthaler

Thiolactomycin was shown to be a potent inhibitor of de novo fatty acid biosynthesis in intact isolated chloroplasts (measured as [14C]acetate incorporation into total fatty acids). In our attempt to further localize the inhibition site we confirmed the inhibition with a fatty acid synthetase preparation, measuring the incorporation of [14C]malonyl-CoA into total fatty acids. From the two proposed enzymic targets of the fatty acid synthetase by thiolactomycin we could exclude the acetyl-CoA: ACP transacetylase. It appears that the inhibition by thiolactomycin occurs on the level of the condensing enzymes, i.e. the 3-oxoacyl-ACP synthases. We also demonstrated that the two starting enzymes of de novo fatty acid biosynthesis, the acetyl-CoA synthetase and the acetyl-CoA carboxylase, are not affected by thiolactomycin.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Regiane Kawasaki ◽  
Rafael A. Baraúna ◽  
Artur Silva ◽  
Marta S. P. Carepo ◽  
Rui Oliveira ◽  
...  

Exiguobacterium antarcticumB7 is extremophile Gram-positive bacteria able to survive in cold environments. A key factor to understanding cold adaptation processes is related to the modification of fatty acids composing the cell membranes of psychrotrophic bacteria. In our study we show thein silicoreconstruction of the fatty acid biosynthesis pathway ofE. antarcticumB7. To build the stoichiometric model, a semiautomatic procedure was applied, which integrates genome information using KEGG and RAST/SEED. Constraint-based methods, namely, Flux Balance Analysis (FBA) and elementary modes (EM), were applied. FBA was implemented in the sense of hexadecenoic acid production maximization. To evaluate the influence of the gene expression in the fluxome analysis, FBA was also calculated using thelog2⁡FCvalues obtained in the transcriptome analysis at 0°C and 37°C. The fatty acid biosynthesis pathway showed a total of 13 elementary flux modes, four of which showed routes for the production of hexadecenoic acid. The reconstructed pathway demonstrated the capacity ofE. antarcticumB7 tode novoproduce fatty acid molecules. Under the influence of the transcriptome, the fluxome was altered, promoting the production of short-chain fatty acids. The calculated models contribute to better understanding of the bacterial adaptation at cold environments.


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