Search results for "PHOSPHATE"
showing 10 items of 1874 documents
New reactive isoeugenol based phosphate flame retardant : toward green epoxy resins
2019
A biobased reactive phosphate flame retardant derived from isoeugenol was synthesized and fully characterized (1H, 13C, 31P NMR, FTIR, MS) with the aim of improving flame retardancy behavior of bio...
Messenger RNA degradation is initiated at the 5′ end and follows sequence- and condition-dependent modes in chloroplasts
2011
Using reporter gene constructs, consisting of the bacterial uidA (GUS) coding region flanked by the 5' and 3' regions of the Chlamydomonas rbcL and psaB genes, respectively, we studied the degradation of mRNAs in the chloroplast of Chlamydomonas reinhardtii in vivo. Extending the 5' terminus of transcripts of the reporter gene by more than 6 nucleotides triggered rapid degradation. Placing a poly(G) tract, known to pause exoribonucleases, in various positions downstream of the 5' terminus blocked rapid degradation of the transcripts. In all these cases the 5' ends of the accumulating GUS transcripts were found to be trimmed to the 5' end of the poly(G) tracts indicating that a 5' → 3' exori…
Mboat7 down-regulation by hyper-insulinemia induces fat accumulation in hepatocytes.
2020
Background: Naturally occurring variation in Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), encoding for an enzyme involved in phosphatidylinositol acyl-chain remodelling, has been associated with fatty liver and hepatic disorders. Here, we examined the relationship between hepatic Mboat7 down-regulation and fat accumulation. Methods: Hepatic MBOAT7 expression was surveyed in 119 obese individuals and in experimental models. MBOAT7 was acutely silenced by antisense oligonucleotides in C57Bl/6 mice, and by CRISPR/Cas9 in HepG2 hepatocytes. Findings: In obese individuals, hepatic MBOAT7 mRNA decreased from normal liver to steatohepatitis, independently of diabetes, inflammatio…
Pre-invasion history and demography shape the genetic variation in the insecticide resistance-related acetylcholinesterase 2 gene in the invasive Col…
2012
Abstract Background Invasive pest species offers a unique opportunity to study the effects of genetic architecture, demography and selection on patterns of genetic variability. Invasive Colorado potato beetle (Leptinotarsa decemlineata) populations have experienced a rapid range expansion and intense selection by insecticides. By comparing native and invasive beetle populations, we studied the origins of organophosphate (OP) resistance-associated mutations in the acetylcholinesterase 2 (AChE2) gene, and the role of selection and demography on its genetic variability. Results Analysis of three Mexican, two US and five European populations yielded a total of 49 haplotypes. Contrary to the exp…
Control of the ribulose 1,5-bisphosphate carboxylase/oxygenase activity by the chloroplastic glutathione pool.
2014
The CO2-fixing activity of ribulose 1,5-bisphosphate carboxylase/oxygenase depends on the redox state of its cysteines. Disulfides like cystamine or 5,5'-dithio-bis(2-nitrobenzoic acid), but not oxidized glutathione, switch the enzyme to the inactive oxidized form. Conversely, thiols like cysteamine, cysteine, dithiotreitol or 2-mercaptoethanol, but not reduced glutathione, recover enzymatic activity after a previous oxidation. Direct regulation of the carboxylase activity by the chloroplastic glutathione pool is hindered by kinetic barriers impeding access to the critical residues. However, reduced glutathione can drive the recovery of activity by means of minute amounts of smaller interme…
Activity and activation state of ribulose-1,5-bisphosphate carboxylase of spruce trees with varying degrees of damage relative to the occurrence of n…
1989
The aim was to determine whether a reduced carboxylation efficiency in needles of damaged spruce trees (Picea abies), is derived from a direct impairment of the ribulose-1,5-bisphosphate carboxylase (RuBP carboxylase) or there is an indirect inhibition of the RuBP carboxylase. In 1985, 1986 and 1987 measurements of RuBP carboxylase activity were carried out at three locations. Trees of different ages and degrees of damage were examined. RuBP carboxylase was assayed using both a rapid extraction method to determine the initial activity and an in vitro test after total activation to determine the total activity. The activation state was calculated as the ratio of initial activity to total act…
Producing more food in a sustainable way is possible : biotechnological and sustainable fertilisation as a way to face population growth
2019
CSIC - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)
Role of glycine-82 as a pivot point during the transition from the inactive to the active form of the yeast Ras2 protein
1991
AbstractRas proteins bind either GDP or GTP with high affinity. However, only the GTP-bound form of the yeast Ras2 protein is able to stimulate adenylyl cyclase. To identify amino acid residues that play a role in the conversion from the GDP-bound to the GTP-bound state of Ras proteins, we have searched for single amino acid substitutions that selectively affected the binding of one of the two nucleotides. We have found that the replacement of glycine-82 of the Ras2 protein by serine resulted in an increased rate of dissociation of Gpp(NH)p, a nonhydrolysable analog of GTP, while the GDP dissociation rate was not significantly modified. Glycine-82 resides in a region that is highly conserve…
Energetic aspects of intramolecular coupling between the nucleotide binding site and the distal switch II region of the yeast RAS2 protein
1994
AbstractWe have studied the interaction of the yeast RAS2 protein with guanine nucleotides using energetic parameters for the dissociation of RAS·nucleotide complexes. The results indicated that a Gly → Ser substitution at position 82 led to an altered interaction with GppNHp and, to a lesser extent, also with GDP. It was also possible to conclude that structural perturbation of Gly82 can stimulate nucleotide release by decreasing the energetic barrier for nucleotide dissociation. This, together with the observation that residues 80 and 81 are involved in the response of RAS to nucleotide exchange factors without affecting GDP binding per se, suggests a potential mechanism for exchange fact…
Study of the First Hours of Microvinification by the Use of Osmotic Stress-response Genes as Probes
2002
Summary When yeast cells are inoculated into grape must for vinification they find stress conditions because of osmolarity, which is due to very high sugar concentration, and pH lower than 4. In this work an analysis of the expression of three osmotic stress induced genes ( GPD1 , HSP12 and HSP104 ) under microvinification conditions is shown as a way to probe those stress situations and the regulatory mechanisms that control them. The results indicate that during the first hours of microvinification there is an increase in the GPD1 mRNA levels with a maximum about one hour after inoculation, and a decrease in the amount of HSP12 and HSP104 mRNAs, although with differences between them. The…