scholarly journals Fatty Alcohols for Wax Esters in Marinobacter aquaeolei VT8: Two Optional Routes in the Wax Biosynthesis Pathway

2013 ◽  
Vol 79 (22) ◽  
pp. 7055-7062 ◽  
Author(s):  
Eric M. Lenneman ◽  
Janet M. Ohlert ◽  
Nagendra P. Palani ◽  
Brett M. Barney
Keyword(s):  
Fatty Alcohol ◽  
Fatty Acyl ◽  
Wax Esters ◽  
Transcriptional Analysis ◽  
Wax Ester ◽  
Fatty Aldehyde ◽  
Marinobacter Aquaeolei

ABSTRACTThe biosynthesis of wax esters in bacteria is accomplished by a unique pathway that combines a fatty alcohol and a fatty acyl coenzyme A substrate. Previousin vitroenzymatic studies indicated that two different enzymes could be involved in the synthesis of the required fatty alcohol inMarinobacter aquaeoleiVT8. In this study, we demonstrate through a series of gene deletions and transcriptional analysis that either enzyme is capable of fulfilling the role of providing the fatty alcohol required for wax ester biosynthesisin vivo, but evolution has clearly selected one of these, a previously characterized fatty aldehyde reductase, as the preferred enzyme to perform this reaction under typical wax ester-accumulating conditions. These results complement previousin vitrostudies and provide the first glimpse into the role of each enzymein vivoin the native organism.

scholarly journals MAZ-LINC00645-GP73 Axis Promotes Hepatocellular Carcinoma Proliferation and Metastasis

2020 ◽  
Author(s):  
Yang Chen ◽  
Huiyan Li ◽  
Chunxun Liu ◽  
Yongmei Han ◽  
Yubao Zhang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanisms ◽  
Tumor Promoter ◽  
Transcriptional Analysis ◽  
Luciferase Reporter ◽  
Chip Assay ◽  
Bioinformatics Analyses

Abstract BACKGROUND: Long non-coding RNAs (lncRNA) have been shown to play important roles in the development and progression of hepatocellular carcinoma (HCC). In this report, we examined the role of lncRNA LINC00645 in HCC. MATERIAL AND METHODS: Based on public databases and integrating bioinformatics analyses, the over-expression of LINC00645 in HCC tissues was detected and further validated in a cohort of liver tissues. A series of in vitro and in vivo functional experiments were executed to investigate the role of LINC00645 in the carcinogenesis and development of HCC. Comprehensive transcriptional analysis, chromatin immunoprecipitation (ChIP) assay, dual-luciferase reporter assay and western blot etc. were performed to explore the molecular mechanisms underlying the functions of LINC00645. RESULTS: LINC00645 was significantly upregulated in HCC cell lines and HCC tissues, which was correlated with poor prognosis in HCC patients. LINC00645 knockdown remarkably suppressed tumor growth in vitro and in vivo. Mechanistically, LINC00645 could competitively bind with miR-141-3p to prevent the degradation of its target gene GP73, which acts as a tumor-promoter in HCC. Furthermore, the ChIP assay showed that the transcription factor MAZ could bind to the LINC00645 promoter and increase its transcription. CONCLUSIONS: Collectively, this study demonstrated that LINC00645 plays a critical regulatory role in hepatocellular carcinoma cells and LINC00645 may serve as a potential diagnostic biomarker and therapeutic target of HCC. Thus, targeting MAZ/LINC00645/miR-141-3p/GP73 signaling axis may prevent the progression of HCC.

scholarly journals Purification, Characterization, and Potential Bacterial Wax Production Role of an NADPH-Dependent Fatty Aldehyde Reductase from Marinobacter aquaeolei VT8

2009 ◽  
Vol 75 (9) ◽  
pp. 2758-2764 ◽  
Author(s):  
Bradley D. Wahlen ◽  
Whitney S. Oswald ◽  
Lance C. Seefeldt ◽  
Brett M. Barney
Keyword(s):  
Fatty Acids ◽  
Specific Activity ◽  
Aromatic Aldehydes ◽  
Wax Esters ◽  
Wax Ester ◽  
Fatty Aldehyde ◽  
Aldehyde Reductase ◽  
Specific Chemical ◽  
Marinobacter Aquaeolei ◽  
Long Chain

ABSTRACT Wax esters, ester-linked fatty acids and long-chain alcohols, are important energy storage compounds in select bacteria. The synthesis of wax esters from fatty acids is proposed to require the action of a four-enzyme pathway. An essential step in the pathway is the reduction of a fatty aldehyde to the corresponding fatty alcohol, although the enzyme responsible for catalyzing this reaction has yet to be identified in bacteria. We report here the purification and characterization of an enzyme from the wax ester-accumulating bacterium Marinobacter aquaeolei VT8, which is a proposed fatty aldehyde reductase in this pathway. The enzyme, a 57-kDa monomer, was expressed in Escherichia coli as a fusion protein with the maltose binding protein on the N terminus and was purified to near homogeneity by using amylose affinity chromatography. The purified enzyme was found to reduce a number of long-chain aldehydes to the corresponding alcohols coupled to the oxidation of NADPH. The highest specific activity was observed for the reduction of decanal (85 nmol decanal reduced/min/mg). Short-chain and aromatic aldehydes were not substrates. The enzyme showed no detectable catalysis of the reverse reaction, the oxidation of decanol by NADP+. The mechanism of the enzyme was probed with several site-specific chemical probes. The possible uses of this enzyme in the production of wax esters are discussed.

scholarly journals Thio Wax Ester Biosynthesis Utilizing the Unspecific Bifunctional Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase of Acinetobacter sp. Strain ADP1

2005 ◽  
Vol 71 (2) ◽  
pp. 790-796 ◽  
Author(s):  
Stefan Uthoff ◽  
Tim Stöveken ◽  
Nikolaus Weber ◽  
Klaus Vosmann ◽  
Erika Klein ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Specific Activity ◽  
Wax Esters ◽  
Wax Ester ◽  
Mineral Salts ◽  
Relative Specific Activity ◽  
In Vitro Biosynthesis ◽  
Wax Ester Synthase

ABSTRACT The bifunctional wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT) from Acinetobacter sp. strain ADP1 (formerly Acinetobacter calcoaceticus ADP1) mediating the biosyntheses of wax esters and triacylglycerols was used for the in vivo and in vitro biosynthesis of thio wax esters and dithio wax esters. For in vitro biosynthesis, 5′His6WS/DGAT comprising an N-terminal His6 tag was purified from the soluble protein fraction of Escherichia coli Rosetta(DE3)pLysS (pET23a::5′His6 atf). By employing SP-Sepharose high-pressure and Ni-nitrilotriacetic acid fast-protein liquid chromatographies, a 19-fold enrichment with a final specific activity of 165.2 nmol mg of protein−1 min−1 was achieved by using 1-hexadecanol and palmitoyl-CoA as substrates. Incubation of purified 5′His6WS/DGAT with 1-hexadecanethiol and palmitoyl-CoA as substrates resulted in the formation of palmitic acid hexadecyl thio ester (10.4% relative specific activity of a 1-hexadecanol control). Utilization of 1,8-octanedithiol and palmitoyl-CoA as substrates led to the formation of 1-S-monopalmitoyloctanedithiol and minor amounts of 1,8-S-dipalmitoyloctanedithiol (59.3% relative specific activity of a 1-hexadecanol control). The latter dithio wax ester was efficiently produced when 1-S-monopalmitoyloctanedithiol and palmitoyl-CoA were used as substrates (13.4% specific activity relative to that of a 1-hexadecanol control). For the in vivo biosynthesis of thio wax esters, the knockout mutant Acinetobacter sp. strain ADP1acr1ΩKm, which is unable to produce fatty alcohols, was used. Cultivation of Acinetobacter sp. strain ADP1acr1ΩKm in the presence of gluconate, 1-hexadecanethiol, and oleic acid in nitrogen-limited mineral salts medium resulted in the accumulation of unusual thio wax esters that accounted for around 1.19% (wt/wt) of the cellular dry weight and consisted mainly of oleic acid hexadecyl thioester as revealed by gas chromatography-mass spectrometry.

scholarly journals Identification of a Residue Affecting Fatty Alcohol Selectivity in Wax Ester Synthase

2012 ◽  
Vol 79 (1) ◽  
pp. 396-399 ◽  
Author(s):  
Brett M. Barney ◽  
Rachel L. Mann ◽  
Janet M. Ohlert
Keyword(s):  
Kinetic Parameters ◽  
Fatty Alcohol ◽  
Biosynthetic Pathway ◽  
Fatty Acyl ◽  
Wax Ester ◽  
Acinetobacter Baylyi ◽  
Content Type ◽  
Marinobacter Aquaeolei ◽  
Acyl Coenzyme A ◽  
Wax Ester Synthase

ABSTRACT The terminal enzyme in the bacterial wax ester biosynthetic pathway is the bifunctional wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT), which utilizes a fatty alcohol and a fatty acyl-coenzyme A (CoA) to synthesize the corresponding wax ester. In this report, we identify a specific residue in WS/DGAT enzymes obtained from Marinobacter aquaeolei VT8 and Acinetobacter baylyi that alters fatty alcohol selectivity and kinetic parameters when modified to alternative residues.

scholarly journals Transcriptional analysis of lung epithelial cells using WGCNA revealed the role of IRF9 and IFI6 genes in SARS-CoV-2 pathogenicity

2020 ◽  
Author(s):  
Hassan Karami ◽  
Afshin Derakhshani ◽  
Mohammad Fereidouni ◽  
Ebrahim Miri-Moghaddam ◽  
Behzad Baradaran ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Experimental Studies ◽  
A549 Cells ◽  
Lung Epithelial Cells ◽  
Transcriptional Analysis ◽  
Type I ◽  
Hub Genes

Abstract The coronavirus disease 2019 (COVID-19) outbreak is an ongoing global health emergence, but the pathogenesis remains unclear. Here, we applied weighted gene co-expression network analysis to comprehensively characterize transcriptional changes in bronchial epithelium cells (NHBE and A549 cells) during SARS-CoV-2 infection. Our analysis identified a network highly correlated to COVID-19 pathogenicity based on MX1, IFIT1, ISG15, IFI6, DDX60, IRF9, PARP9, PGLYRP4, IL36G, SAA2 and IL-8 hub genes. The results also indicated a unique transcriptional signatures of infected cells including IFI6 and IRF9 as novel gene candidates and suggested their prospective mechanism in COVID-19 pathogenesis. The result of hub genes enrichment showed that the most correlation topic in biological process and KEGG were type I interferon signaling pathway, IL-17 signaling pathway, cytokine mediated signaling pathway, and defense response to virus categories which all play significant roles in restricting viral infection. Also according to the drug-target network, we recognized 54 FDA-approved drug candidates for other indications could potentially use for the treatment of COVID-19 patients through regulation of six hub genes of the co-expression network. Our findings also showed that the 19 experimentally validated miRNAs regulated the co-expression network through 5 hub genes (SLC19A3, FAM13A, PLA2G16, and HRASLS5). In conclusion, these hub genes had potential roles in the translational medicine and might become promising therapeutic targets further in vitro and in vivo experimental studies are needed to evaluate the role of above mentioned genes in COVID-19.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

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