Search results for "030302 biochemistry & molecular biology"
showing 8 items of 238 documents
In vivo evaluation of the interaction between the Escherichia coli IGP synthase subunits using the Bacterial Two-Hybrid system
2020
ABSTRACT Histidine biosynthesis is one of the most characterized metabolic routes for its antiquity and its central role in cellular metabolism; indeed, it represents a cross-road between nitrogen metabolism and de novo synthesis of purines. This interconnection is due to the activity of imidazole glycerol phosphate synthase, a heterodimeric enzyme constituted by the products of two his genes, hisH and hisF, encoding a glutamine amidotransferase and a cyclase, respectively. Despite their interaction was suggested by several in vitro experiments, their in vivo complex formation has not been demonstrated. On the contrary, the analysis of the entire Escherichia coli interactome performed using…
Polyunsaturated n-3 and n-6 fatty acids at a low level in the diet alter mitochondrial outer membrane parameters in Wistar rat liver
1995
Abstract This study was designed to examine whether n-3 and n-6 polyunsaturated fatty acids (PUFA) at a very low level in the diet (about 0.2%) may alter the fatty acid composition of mitochondrial outer membranes and the characteristics of carnitine palmitoyltransferase I (CPTI) activity in the liver of normal Wistar rats. The animals were fed diets containing different oil mixtures (5% wt/wt) with the same ratio of n-6 n-3 fatty acids supplied either as fish oil or arachidonic acid concentrate. The cholesterol content of the mitochondrial outer membranes from liver was similar for all diets, while the percentage of 22:6n-3 and 20:4n-6 in phospholipids was enhanced with the diets containin…
A genomic reappraisal of symbiotic function in the aphid/Buchnera symbiosis: reduced transporter sets and variable membrane organisations.
2011
International audience; Buchnera aphidicola is an obligate symbiotic bacterium that sustains the physiology of aphids by complementing their exclusive phloem sap diet. In this study, we reappraised the transport function of different Buchnera strains, from the aphids Acyrthosiphon pisum, Schizaphis graminum, Baizongia pistaciae and Cinara cedri, using the re-annotation of their transmembrane proteins coupled with an exploration of their metabolic networks. Although metabolic analyses revealed high interdependencies between the host and the bacteria, we demonstrate here that transport in Buchnera is assured by low transporter diversity, when compared to free-living bacteria, being mostly bas…
Experimental evolution of an RNA virus in cells with innate immunity defects
2015
Experimental evolution studies have shown that RNA viruses respond rapidly to directional selection and thus can adapt efficiently to changes in host cell tropism, antiviral drugs, or other imposed selective pressures. However, the evolution of RNA viruses under relaxed selection has been less extensively explored. Here, we evolved vesicular stomatitis virus in mouse embryonic fibroblasts knocked-out for PKR, a protein with a central role in antiviral innate immunity. Vesicular stomatitis virus adapted to PKR-negative mouse embryonic fibroblasts in a gene-specific manner, since the evolved viruses exhibited little or no fitness improvement in PKR-positive cells. Full-length sequencing revea…
Protein tyrosine nitration and thiol oxidation by peroxynitrite-strategies to prevent these oxidative modifications.
2013
The reaction product of nitric oxide and superoxide, peroxynitrite, is a potent biological oxidant. The most important oxidative protein modifications described for peroxynitrite are cysteine-thiol oxidation and tyrosine nitration. We have previously demonstrated that intrinsic heme-thiolate (P450)-dependent enzymatic catalysis increases the nitration of tyrosine 430 in prostacyclin synthase and results in loss of activity which contributes to endothelial dysfunction. We here report the sensitive peroxynitrite-dependent nitration of an over-expressed and partially purified human prostacyclin synthase (3.3 μM) with an EC50 value of 5 μM. Microsomal thiols in these preparations effectively co…
CYGD: the Comprehensive Yeast Genome Database.
2005
The comprehensive resource is available under http://mips.gsf.de/genre/proj/yeast/.; International audience; The Comprehensive Yeast Genome Database (CYGD) compiles a comprehensive data resource for information on the cellular functions of the yeast Saccharomyces cerevisiae and related species, chosen as the best understood model organism for eukaryotes. The database serves as a common resource generated by a European consortium, going beyond the provision of sequence information and functional annotations on individual genes and proteins. In addition, it provides information on the physical and functional interactions among proteins as well as other genetic elements. These cellular network…
CVB3 VP1 interacts with MAT1 to inhibit cell proliferation by interfering with Cdk-activating kinase complex activity in CVB3-induced acute pancreati…
2021
Coxsackievirus B3 (CVB3) belongs to the genus Enterovirus of the family Picornaviridae and can cause acute acinar pancreatitis in adults. However, the molecular mechanisms of pathogenesis underlying CVB3-induced acute pancreatitis have remained unclear. In this study, we discovered that CVB3 capsid protein VP1 inhibited pancreatic cell proliferation and exerted strong cytopathic effects on HPAC cells. Through yeast two-hybrid, co-immunoprecipitation, and confocal microscopy, we show that Menage a trois 1 (MAT1), a subunit of the Cdk-Activating Kinase (CAK) complex involved in cell proliferation and transcription, is a novel interaction protein with CVB3 VP1. Moreover, CVB3 VP1 inhibited MAT…
Modeling multipartite virus evolution: the genome formula facilitates rapid adaptation to heterogeneous environments
2020
Multipartite viruses have two or more genome segments, and package different segments into different particle types. Although multipartition is thought to have a cost for virus transmission, its benefits are not clear. Recent experimental work has shown that the equilibrium frequency of viral genome segments, the setpoint genome formula (SGF), can be unbalanced and host-species dependent. These observations have reinvigorated the hypothesis that changes in genome-segment frequencies can lead to changes in virus-gene expression that might be adaptive. Here we explore this hypothesis by developing models of bipartite virus infection, leading to a threefold contribution. First, we show that th…