scholarly journals Regulation of l-Alanine Dehydrogenase in Rhizobium leguminosarum bv. viciae and Its Role in Pea Nodules

2004 ◽  
Vol 186 (3) ◽  
pp. 842-849 ◽  
Author(s):  
Emma Lodwig ◽  
Shalini Kumar ◽  
David Allaway ◽  
Alex Bourdes ◽  
Jürgen Prell ◽  
...  
Keyword(s):  
Rhizobium Leguminosarum ◽  
De Novo ◽  
Dry Weight ◽  
Northern Blotting ◽  
Alanine Dehydrogenase ◽  
Living Culture ◽  
Optimal Functioning ◽  
Alanine Synthesis ◽  
Sole Product

ABSTRACT Alanine dehydrogenase (AldA) is the principal enzyme with which pea bacteroids synthesize alanine de novo. In free-living culture, AldA activity is induced by carboxylic acids (succinate, malate, and pyruvate), although the best inducer is alanine. Measurement of the intracellular concentration of alanine showed that AldA contributes to net alanine synthesis in laboratory cultures. Divergently transcribed from aldA is an AsnC type regulator, aldR. Mutation of aldR prevents induction of AldA activity. Plasmid-borne gusA fusions showed that aldR is required for transcription of both aldA and aldR; hence, AldR is autoregulatory. However, plasmid fusions containing the aldA-aldR intergenic region could apparently titrate out AldR, sometimes resulting in a complete loss of AldA enzyme activity. Therefore, integrated aldR::gusA and aldA::gusA fusions, as well as Northern blotting, were used to confirm the induction of aldA activity. Both aldA and aldR were expressed in the II/III interzone and zone III of pea nodules. Overexpression of aldA in bacteroids did not alter the ability of pea plants to fix nitrogen, as measured by acetylene reduction, but caused a large reduction in the size and dry weight of plants. This suggests that overexpression of aldA impairs the ability of bacteroids to donate fixed nitrogen that the plant can productively assimilate. We propose that the role of AldA may be to balance the alanine level for optimal functioning of bacteroid metabolism rather than to synthesize alanine as the sole product of N2 reduction.

scholarly journals The role of phosphoenolpyruvate carboxykinase in muscle alanine synthesis

1984 ◽  
Vol 224 (3) ◽  
pp. 971-976 ◽  
Author(s):  
T N Palmer ◽  
M A Caldecourt ◽  
J P Warner ◽  
M C Sugden
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
De Novo ◽  
Tricarboxylic Acid Cycle ◽  
Specific Inhibitor ◽  
Glycolytic Flux ◽  
Metabolic Role ◽  
14Co2 Production ◽  
Alanine Synthesis ◽  
Pep Carboxykinase

3-Mercaptopicolinic acid (3-MPA) is reportedly a specific inhibitor of phosphoenolpyruvate (PEP) carboxykinase and has hitherto been used accordingly to elucidate the metabolic role of PEP carboxykinase in vitro and in vivo. We show that 3-MPA has multiple effects on intermediary metabolism in hemidiaphragms from 40 h-starved rats. It decreases the release of lactate + pyruvate and alanine in hemidiaphragms provided with no added substrate or with valine, leucine or isoleucine. Moreover, irrespective of the substrate provided (none, valine, leucine, isoleucine, glucose, acetate, oleate), 3-MPA decreases the [lactate]/[pyruvate] ratio. 3-MPA is without effect on 14CO2 production from [U-14C]valine, [1-14C]valine, [1-14C]leucine, [U-14C]isoleucine or [1-14C]oleate, but stimulates 14CO2 production from [U-14C]glucose and [1-14C]pyruvate and inhibits 14CO2 production from [1-14C]acetate. Glycolytic flux (measured as 3H2O formation from [5-3H]glucose) is stimulated by 3-MPA. It is concluded that 3-MPA has site(s) of actions other than PEP carboxykinase and that the putative role of PEP carboxykinase in alanine synthesis de novo in skeletal muscle from tricarboxylic acid-cycle intermediates and related amino acids requires reappraisal.

scholarly journals De Novo Alanine Synthesis by Bacteroids of Mesorhizobium loti Is Not Required for Nitrogen Transfer in the Determinate Nodules of Lotus corniculatus

2005 ◽  
Vol 187 (15) ◽  
pp. 5493-5495 ◽  
Author(s):  
Shalini Kumar ◽  
Alexandre Bourdès ◽  
Philip Poole
Keyword(s):  
Enzyme Activity ◽  
De Novo ◽  
Lotus Corniculatus ◽  
Nitrogen Transfer ◽  
Mesorhizobium Loti ◽  
Alanine Dehydrogenase ◽  
Alanine Synthesis ◽  
Secretion Product ◽  
Cultured Bacteria ◽  
Nitrogen Secretion

ABSTRACT Deletion of both alanine dehydrogenase genes (aldA) in Mesorhizobium loti resulted in the loss of AldA enzyme activity from cultured bacteria and bacteroids but had no effect on the symbiotic performance of Lotus corniculatus plants. Thus, neither indeterminate pea nodules nor determinate L. corniculatus nodules export alanine as the sole nitrogen secretion product.

scholarly journals The role of a gene cluster for trehalose metabolism in dehydration tolerance of the filamentous cyanobacterium Anabaena sp. PCC 7120

Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 979-987 ◽  
Author(s):  
Akiyoshi Higo ◽  
Hiroshi Katoh ◽  
Kazuko Ohmori ◽  
Masahiko Ikeuchi ◽  
Masayuki Ohmori
Keyword(s):  
Gene Disruption ◽  
Expression Profiles ◽  
Dry Weight ◽  
Northern Blotting ◽  
Filamentous Cyanobacterium ◽  
Trehalose Synthase ◽  
Dehydration Tolerance ◽  
Cyanobacterium Anabaena ◽  
Pcc 7120

Expression of the genes for trehalose synthesis (mts and mth, encoding maltooligosyl trehalose synthase and hydrolase) and trehalose hydrolysis (treH) in Anabaena sp. PCC 7120 was up-regulated markedly upon dehydration. However, the amount of trehalose accumulated during dehydration was small, whereas a large amount of sucrose was accumulated. Northern blotting analysis revealed that these genes were transcribed as an operon. Gene disruption of mth resulted in a decrease in the trehalose level and in tolerance during dehydration. In contrast, gene disruption of treH resulted in an increase in both the amount of trehalose and tolerance. These results suggest that trehalose is important for the dehydration tolerance of this cyanobacterium. The amount of trehalose accumulated during dehydration was small, corresponding to 0·05–0·1 % of dry weight, suggesting that trehalose did not stabilize proteins and membranes directly during dehydration. To reveal the role of trehalose, the expression profiles of the wild-type strain and gene disruptants during dehydration were compared by using oligomeric DNA microarray. It was found that the expression of two genes, one of which encodes a cofactor of a chaperone DnaK, correlated with trehalose content, suggesting that a chaperone system induced by trehalose is important for the dehydration tolerance of Anabaena sp. PCC 7120.

Posttransplant CMV infection and the role of immunosuppression (Sponsor: Novartis Pharma GmbH, Nürnberg)

2016 ◽  
Vol 04 (01) ◽  
pp. 4-10
Keyword(s):  
Lower Incidence ◽  
Paradigm Shift ◽  
Mtor Inhibitor ◽  
De Novo ◽  
Expert Panel ◽  
Risk Of Infection ◽  
Cmv Infection ◽  
Expert Meeting ◽  
Selection Of

AbstractImmunosuppression permits graft survival after transplantation and consequently a longer and better life. On the other hand, it increases the risk of infection, for instance with cytomegalovirus (CMV). However, the various available immunosuppressive therapies differ in this regard. One of the first clinical trials using de novo everolimus after kidney transplantation [1] already revealed a considerably lower incidence of CMV infection in the everolimus arms than in the mycophenolate mofetil (MMF) arm. This result was repeatedly confirmed in later studies [2–4]. Everolimus is now considered a substance with antiviral properties. This article is based on the expert meeting “Posttransplant CMV infection and the role of immunosuppression”. The expert panel called for a paradigm shift: In a CMV prevention strategy the targeted selection of the immunosuppressive therapy is also a key element. For patients with elevated risk of CMV, mTOR inhibitor-based immunosuppression is advantageous as it is associated with a significantly lower incidence of CMV events.

Accumulation of microelements by different invertebrate trophic groups on wasted lands

2017 ◽  
Vol 7 (4) ◽  
pp. 30-34 ◽  
Author(s):  
O. A. Didur ◽  
Yu. L. Kulbachko ◽  
V. Y. Gasso
Keyword(s):  
Active Agent ◽  
Dry Weight ◽  
Nature Management ◽  
Habitat Transformation ◽  
Natural Landscapes ◽  
Invertebrate Animals ◽  
Risk Of Disease ◽  
Ore Dressing ◽  
Processing Enterprise

<p>The problem of transformation of natural landscapes resulted from the negative technogenic impact is highlighted. It is shown that mining enterprises are powerful anthropo-technical sources of organic and inorganic toxicants entering the environment. Their wastes pollute all components of the ecosystems and negatively influence human health by increasing a risk of disease. The nature of the accumulation of trace elements (Fe, Cu, Zn, Ni, Cd, and Pb) by invertebrate animals of various functional groups under conditions of anthropo-technogenic pressure was studied. The sample plots were located on self-overgrowing sites with ruderal vegetation located in the immediate vicinity of the Mangan ore-dressing and processing enterprise (Dnipropetrovsk region). It is quite naturally that among the studied biogenic microelements (Fe, Cu, Zn and Ni), the phyto-, zoo-, and saprophages in the investigated zone of technogenic pollution most actively accumulate Fe:<em> </em>22758, 17516 and 18884 mg/kg dry weight on average, respectively. There are significant differences (p ≤ 0.05) in the content of studied microelements between saprophages and phytophages. The saprophages accumulate such trace metals as Mn, Cu, Zn and Cd in high quantities, but Ni and Pb – in smaller ones. The saprophagous functional group of invertebrates is an active agent of detritogenesis, in the conditions of modern nature management it acts as a powerful element of ecosystem engineering (habitat transformation), the main ecological role of which is to modify the habitat of other soil biota. In addition, the saprophages fulfil their concentrating geochemical function. They actively participate in the most important soil biochemical process: the formation of humus, the migration of microelements along trophic chains, the biological cycle in general, and provide such supporting ecosystem services as increasing soil fertility and nutrient cycling.</p>

249 ROLE OF DE NOVO LIPOGENESIS IN GROWING VERY LOW BIRTH WEIGHT BREASTFED INFANTS.

2004 ◽  
Vol 52 (Suppl 1) ◽  
pp. S122.6-S123
Author(s):  
M. Garg ◽  
C. Bell ◽  
L. Rogers ◽  
S. Bassilian ◽  
W. N.P. Lee
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Very Low Birth Weight ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Breastfed Infants

scholarly journals Phytoextraction of Lead Using a Hedge Plant [Alternanthera bettzickiana (Regel) G. Nicholson]: Physiological and Biochemical Alterations through Bioresource Management

2021 ◽  
Vol 13 (9) ◽  
pp. 5074
Author(s):  
Urooj Kanwal ◽  
Muhammad Ibrahim ◽  
Farhat Abbas ◽  
Muhammad Yamin ◽  
Fariha Jabeen ◽  
...  
Keyword(s):  
Citric Acid ◽  
Growth Parameters ◽  
Cost Effective ◽  
Dry Weight ◽  
Citric Acid Concentration ◽  
Biochemical Alterations ◽  
Biomass Plant ◽  
Environmentally Friendly Approach ◽  
Pb Concentration

Phytoremediation is a cost-effective and environmentally friendly approach that can be used for the remediation of metals in polluted soil. This study used a hedge plant–calico (Alternanthera bettzickiana (Regel) G. Nicholson) to determine the role of citric acid in lead (Pb) phytoremediation by exposing it to different concentrations of Pb (0, 200, 500, and 1000 mg kg−1) as well as in a combination with citric acid concentration (0, 250, 500 µM). The analysis of variance was applied on results for significant effects of the independent variables on the dependent variables using SPSS (ver10). According to the results, maximum Pb concentration was measured in the upper parts of the plant. An increase in dry weight biomass, plant growth parameters, and photosynthetic contents was observed with the increase of Pb application (200 mg kg−1) in soil while a reduced growth was experienced at higher Pb concentration (1000 mg kg−1). The antioxidant enzymatic activities like superoxide dismutase (SOD) and peroxidase (POD) were enhanced under lower Pb concentration (200, 500 mg kg−1), whereas the reduction occurred at greater metal concentration Pb (1000 mg kg−1). There was a usual reduction in electrolyte leakage (EL) at lower Pb concentration (200, 500 mg kg−1), whereas EL increased at maximum Pb concentration (1000 mg kg−1). We concluded that this hedge plant, A. Bettzickiana, has the greater ability to remediate polluted soils aided with citric acid application.

scholarly journals LncRNA CRNDE attenuates chemoresistance in gastric cancer via SRSF6-regulated alternative splicing of PICALM

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Feifei Zhang ◽  
Hui Wang ◽  
Jiang Yu ◽  
Xueqing Yao ◽  
Shibin Yang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Alternative Splicing ◽  
Noncoding Rna ◽  
De Novo ◽  
Acquired Resistance ◽  
Genetic Alterations ◽  
Clinical Samples ◽  
Autophagy Flux ◽  
Resistance To Chemotherapy

AbstractDe novo and acquired resistance, which are mainly mediated by genetic alterations, are barriers to effective routine chemotherapy. However, the mechanisms underlying gastric cancer (GC) resistance to chemotherapy are still unclear. We showed that the long noncoding RNA CRNDE was related to the chemosensitivity of GC in clinical samples and a PDX model. CRNDE was decreased and inhibited autophagy flux in chemoresistant GC cells. CRNDE directly bound to splicing protein SRSF6 to reduce its protein stability and thus regulate alternative splicing (AS) events. We determined that SRSF6 regulated the PICALM exon 14 skip splice variant and triggered a significant S-to-L isoform switch, which contributed to the expression of the long isoform of PICALM (encoding PICALML). Collectively, our findings reveal the key role of CRNDE in autophagy regulation, highlighting the significance of CRNDE as a potential prognostic marker and therapeutic target against chemoresistance in GC.

scholarly journals Coenzyme Q10 and Immune Function: An Overview

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 759
Author(s):  
David Mantle ◽  
Robert A. Heaton ◽  
Iain P. Hargreaves
Keyword(s):  
Immune System ◽  
Immune Function ◽  
Coenzyme Q10 ◽  
Mitochondrial Respiratory Chain ◽  
Inflammatory Gene Expression ◽  
Optimal Functioning ◽  
Human Immune ◽  
Coq10 Supplementation ◽  
Lipid Soluble Antioxidant

Coenzyme Q10 (CoQ10) has a number of important roles in the cell that are required for optimal functioning of the immune system. These include its essential role as an electron carrier in the mitochondrial respiratory chain, enabling the process of oxidative phosphorylation to occur with the concomitant production of ATP, together with its role as a potential lipid-soluble antioxidant, protecting the cell against free radical-induced oxidation. Furthermore, CoQ10 has also been reported to have an anti-inflammatory role via its ability to repress inflammatory gene expression. Recently, CoQ10 has also been reported to play an important function within the lysosome, an organelle central to the immune response. In view of the differing roles CoQ10 plays in the immune system, together with the reported ability of CoQ10 supplementation to improve the functioning of this system, the aim of this article is to review the current literature available on both the role of CoQ10 in human immune function and the effect of CoQ10 supplementation on this system.

scholarly journals Discovery of novel community-relevant small proteins in a simplified human intestinal microbiome

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hannes Petruschke ◽  
Christian Schori ◽  
Sebastian Canzler ◽  
Sarah Riesbeck ◽  
Anja Poehlein ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Intestinal Microbiota ◽  
De Novo ◽  
Bacterial Species ◽  
Intestinal Microbiome ◽  
Single Strain ◽  
Small Proteins ◽  
Human Intestinal Microbiota ◽  
Wide Range

Abstract Background The intestinal microbiota plays a crucial role in protecting the host from pathogenic microbes, modulating immunity and regulating metabolic processes. We studied the simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species with a particular focus on the discovery of novel small proteins with less than 100 amino acids (= sProteins), some of which may contribute to shape the simplified human intestinal microbiota. Although sProteins carry out a wide range of important functions, they are still often missed in genome annotations, and little is known about their structure and function in individual microbes and especially in microbial communities. Results We created a multi-species integrated proteogenomics search database (iPtgxDB) to enable a comprehensive identification of novel sProteins. Six of the eight SIHUMIx species, for which no complete genomes were available, were sequenced and de novo assembled. Several proteomics approaches including two earlier optimized sProtein enrichment strategies were applied to specifically increase the chances for novel sProtein discovery. The search of tandem mass spectrometry (MS/MS) data against the multi-species iPtgxDB enabled the identification of 31 novel sProteins, of which the expression of 30 was supported by metatranscriptomics data. Using synthetic peptides, we were able to validate the expression of 25 novel sProteins. The comparison of sProtein expression in each single strain versus a multi-species community cultivation showed that six of these sProteins were only identified in the SIHUMIx community indicating a potentially important role of sProteins in the organization of microbial communities. Two of these novel sProteins have a potential antimicrobial function. Metabolic modelling revealed that a third sProtein is located in a genomic region encoding several enzymes relevant for the community metabolism within SIHUMIx. Conclusions We outline an integrated experimental and bioinformatics workflow for the discovery of novel sProteins in a simplified intestinal model system that can be generically applied to other microbial communities. The further analysis of novel sProteins uniquely expressed in the SIHUMIx multi-species community is expected to enable new insights into the role of sProteins on the functionality of bacterial communities such as those of the human intestinal tract.

Sign in / Sign up

Export Citation Format

Share Document