scholarly journals Disruption of AtHAK/KT/KUP9 enhances plant cesium accumulation under low potassium supply

2020 ◽  
Author(s):  
Laure Genies ◽  
Ludovic Martin ◽  
Satomi Kanno ◽  
Serge Chiarenza ◽  
Loïc Carasco ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Primary Role ◽  
In Planta ◽  
Experimental Conditions ◽  
Low Potassium ◽  
Significant Impairment ◽  
Potassium Supply ◽  
Mutant Lines ◽  
Low K

ABSTRACTUnderstanding molecular mechanisms which underlie transport of cesium (Cs+) in plants is important to limit entry of its radioisotopes from contaminated area to the food chain. The potentially toxic element Cs+, which is not involved in any biological process, is chemically closed to the macronutrient potassium (K+). Among the multiple K+ carriers, the high-affinity K+ transporters family HAK/KT/KUP is thought to be relevant in mediating opportunistic Cs+ transport. On the 13 KUP identified in Arabidopsis thaliana, only HAK5, the major contributor to root K+ acquisition under low K+ supply, has been functionally demonstrated to be involved in Cs+ uptake in planta. In the present study, we showed that accumulation of Cs+ increased by up to 30% in two A. thaliana mutant lines lacking KUP9 and grown under low K+ supply. Since further experiments revealed that Cs+ release from contaminated plants to the external medium is proportionally lower in the two kup9 mutants, we proposed that KUP9 disruption could impair Cs+ efflux. By contrast, we did not measure significant impairment of K+ status in kup9 mutants suggesting that KUP9 disruption does not alter substantially K+ transport in experimental conditions used here. Putative primary role of KUP9 in plants is further discussed.

scholarly journals Anti-Inflammatory and Antinociceptive Activities of Anthraquinone-2-Carboxylic Acid

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Jae Gwang Park ◽  
Seung Cheol Kim ◽  
Yun Hwan Kim ◽  
Woo Seok Yang ◽  
Yong Kim ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Molecular Mechanisms ◽  
Interleukin 1 ◽  
Nuclear Factor ◽  
Experimental Conditions ◽  
Gene Assay ◽  
Anti Inflammatory ◽  
Gastric Irritation

Anthraquinone compounds are one of the abundant polyphenols found in fruits, vegetables, and herbs. However, thein vivoanti-inflammatory activity and molecular mechanisms of anthraquinones have not been fully elucidated. We investigated the activity of anthraquinones using acute inflammatory and nociceptive experimental conditions. Anthraquinone-2-carboxylic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA), one of the major anthraquinones identified from Brazilian taheebo, ameliorated various inflammatory and algesic symptoms in EtOH/HCl- and acetylsalicylic acid- (ASA-) induced gastritis, arachidonic acid-induced edema, and acetic acid-induced abdominal writhing without displaying toxic profiles in body and organ weight, gastric irritation, or serum parameters. In addition, AQCA suppressed the expression of inflammatory genes such as cyclooxygenase- (COX-) 2 in stomach tissues and lipopolysaccharide- (LPS-) treated RAW264.7 cells. According to reporter gene assay and immunoblotting analyses, AQCA inhibited activation of the nuclear factor- (NF-)κB and activator protein- (AP-) 1 pathways by suppression of upstream signaling involving interleukin-1 receptor-associated kinase 4 (IRAK1), p38, Src, and spleen tyrosine kinase (Syk). Our data strongly suggest that anthraquinones such as AQCA act as potent anti-inflammatory and antinociceptive componentsin vivo, thus contributing to the immune regulatory role of fruits and herbs.

scholarly journals The TUTase URT1 connects decapping activators and prevents the accumulation of excessively deadenylated mRNAs to avoid siRNA biogenesis

2020 ◽  
Author(s):  
Hélène Scheer ◽  
Caroline de Almeida ◽  
Emilie Ferrier ◽  
Quentin Simonnot ◽  
Laure Poirier ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Growth And Development ◽  
Molecular Mechanisms ◽  
Tail Length ◽  
Mrna Degradation ◽  
In Planta ◽  
Rna Helicases ◽  
Eukaryotic Mrnas

AbstractUridylation is a widespread modification destabilizing eukaryotic mRNAs. Yet, molecular mechanisms underlying TUTase-mediated mRNA degradation remain mostly unresolved. Here, we report that the Arabidopsis TUTase URT1 participates in a molecular network connecting several translational repressors/decapping activators. URT1 directly interacts with DECAPPING 5 (DCP5), the Arabidopsis ortholog of human LSM14 and yeast Scd6, and this interaction connects URT1 to additional decay factors like DDX6/Dhh1-like RNA helicases. Nanopore direct RNA sequencing reveals a global role of URT1 in shaping poly(A) tail length, notably by preventing the accumulation of excessively deadenylated mRNAs. Based on in vitro and in planta data, we propose a model that explains how URT1 could reduce the accumulation of oligo(A)-tailed mRNAs both by favoring their degradation and because 3’ terminal uridines intrinsically hinder deadenylation. Importantly, preventing the accumulation of excessively deadenylated mRNAs avoids the biogenesis of illegitimate siRNAs that silence endogenous mRNAs and perturb Arabidopsis growth and development.

Liver enzyme activities in ammonia fixation by the rat

1962 ◽  
Vol 203 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Gustavo Flores ◽  
Adolfo Rosado ◽  
Jesús Torres ◽  
Guillermo Soberón
Keyword(s):  
Glutamine Synthetase ◽  
Liver Enzymes ◽  
Hepatic Veins ◽  
Primary Role ◽  
Experimental Conditions ◽  
Glutamic Dehydrogenase ◽  
Apparent Reason ◽  
Protein Free Diet ◽  
Ammonia Fixation

Capacity to handle an ammonia load was explored in rats submitted to different experimental conditions, by means of intraportal administration of NH4Cl solution and measurement of ammonia in blood removed at various times from hepatic veins. Liver enzymes that participate in ammonia fixation (glutamine synthetase, carbamyl phosphate synthetase, ornithine transcarbamylase, arginine synthetase, arginase, and glutamic dehydrogenase) were assayed in different animals under the same conditions and results were correlated with ability to clear ammonia; ATP was determined in some of the groups. All groups showed a decreased capacity to clear ammonia from blood. In animals starved during 4 days, in those fed a protein-free diet or a diet that contained zein as a source of protein, in those chronically intoxicated with CCl4, and in those partially hepatectomized, the impaired ability could be related to a diminution of all enzymes assayed. In animals given an acute dose of CCl4 and in those administered NH4Cl solution as drinking water the defect could be explained by a decreased activity of some enzymes tested. In anemic animals and in those made hypoxic, a drop in ATP content of liver was the apparent reason of impairment. The study emphasized the primary role of ATP and of the enzymes glutamine synthetase and arginine synthetase (splitting and condensing enzymes) in removal of ammonia.

scholarly journals Previously uncharacterized Salmonella enterica genes required for swarming play a role in seedling colonization

Microbiology ◽  
2009 ◽  
Vol 155 (11) ◽  
pp. 3701-3709 ◽  
Author(s):  
Jeri D. Barak ◽  
Lisa Gorski ◽  
Anita S. Liang ◽  
Koh-Eun Narm
Keyword(s):  
Salmonella Enterica ◽  
Molecular Mechanisms ◽  
Plant Colonization ◽  
In Planta ◽  
Associated Bacteria ◽  
Biofilm Production ◽  
C Terminus ◽  
Alfalfa Seed ◽  
Osmotic Agent

Incidences of bacterial foodborne illness caused by ingestion of fresh produce are rising. Instead of this being due to incidental contamination, the animal pathogen Salmonella enterica utilizes specific molecular mechanisms to attach to and colonize plants. This work characterizes two S. enterica genes of unknown function: a putative periplasmic protein, STM0278, and a putative protein with a hydrolase in the C-terminus, STM0650. STM0278 and STM0650 are important for seedling colonization but appear to have different roles during the process of colonization. Mutants of either STM0278 or STM0650 showed reduced colonization of alfalfa seedlings at 24 h, and the STM0278 mutant also showed reduced colonization at 48 h. Both genes were expressed in planta at 4 h following inoculation of 3-day-old seedlings and at 72 h after seed inoculation. This suggests that the role of STM0650 in seedling colonization is less important later in the process or is duplicated by other mechanisms. Mutants of STM0278 and STM0650 were defective in swarming. The STM0278 mutant failed to swarm in 24 h, while swarming of the STM0650 mutant was delayed. Addition of surfactant restored swarming of the STM0278 mutant, suggesting that STM0278 is involved in surfactant or osmotic agent production or deployment. Alfalfa seed exudates as the sole nutrient source were capable of perpetuating S. enterica swarming. Sequence analysis revealed sequences homologous to STM0278 and STM0650 in plant-associated bacteria, but none in Escherichia coli. Phylogenetic analysis of STM0650 showed similar sequences from diverse classes of plant-associated bacteria. Bacteria that preferentially colonize roots, including S. enterica, may use a similar hydrolase for swarming or biofilm production on plants. Multicellular behaviours by S. enterica appear central to plant colonization. S. enterica genes involved in plant colonization and survival outside of a host are most likely among the ‘function unknown’ genes of this bacterium.

scholarly journals The TUTase URT1 connects decapping activators and prevents the accumulation of excessively deadenylated mRNAs to avoid siRNA biogenesis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hélène Scheer ◽  
Caroline de Almeida ◽  
Emilie Ferrier ◽  
Quentin Simonnot ◽  
Laure Poirier ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Growth And Development ◽  
Molecular Mechanisms ◽  
Tail Length ◽  
Mrna Degradation ◽  
In Planta ◽  
Rna Helicases ◽  
Eukaryotic Mrnas

AbstractUridylation is a widespread modification destabilizing eukaryotic mRNAs. Yet, molecular mechanisms underlying TUTase-mediated mRNA degradation remain mostly unresolved. Here, we report that the Arabidopsis TUTase URT1 participates in a molecular network connecting several translational repressors/decapping activators. URT1 directly interacts with DECAPPING 5 (DCP5), the Arabidopsis ortholog of human LSM14 and yeast Scd6, and this interaction connects URT1 to additional decay factors like DDX6/Dhh1-like RNA helicases. Nanopore direct RNA sequencing reveals a global role of URT1 in shaping poly(A) tail length, notably by preventing the accumulation of excessively deadenylated mRNAs. Based on in vitro and in planta data, we propose a model that explains how URT1 could reduce the accumulation of oligo(A)-tailed mRNAs both by favoring their degradation and because 3’ terminal uridines intrinsically hinder deadenylation. Importantly, preventing the accumulation of excessively deadenylated mRNAs avoids the biogenesis of illegitimate siRNAs that silence endogenous mRNAs and perturb Arabidopsis growth and development.

scholarly journals Fungi Associated With Woody Tissues of European Beech and Their Impact on Tree Health

2021 ◽  
Vol 12 ◽  
Author(s):  
Gitta Jutta Langer ◽  
Johanna Bußkamp
Keyword(s):  
Fungal Pathogens ◽  
Complex Disease ◽  
European Beech ◽  
Post Inoculation ◽  
Primary Role ◽  
In Planta ◽  
Experimental Conditions ◽  
Tree Health ◽  
Woody Tissues ◽  
The Impact

Filamentous fungi associated with woody tissues of European Beech (Fagus sylvatica) and isolated from diseased trees and healthy trees were examined in relation to their impact on tree health. To this end, classical culture-based isolation methods, in planta inoculations and fungal identification using ITS-barcode and morphological characters were used. Stem endophytes of healthy beech saplings collected in German forests were isolated to determine endophyte communities in woody stem tissues. Pathogenicity tests were performed on living potted beech saplings using twelve selected fungal pathogens and wood inhabiting fungi (Hypocreales, Botryosphaeriales, and Xylariales) originating mainly from European beech with symptoms of the complex disease Vitality loss, or from bark necroses, or known to be common endophytes of beech. The impact of these ascomycetous fungi with respect to tree health was discussed. The potential influences of endophytic fungi of beech and of test conditions are discussed in relation to the success of inoculation. All tested fungal strains except for Neonectria ditissima were able to establish themselves post inoculation in the beech stems and caused necroses when there was sufficient water, but at different severities. Under the experimental conditions, Botryosphaeria corticola was shown to be the most virulent tested latent pathogen against F. sylvatica. In the context of climate change and global warming, the tested Botryosphaeriaceae are able to play a primary role in the disease progress of Vitality loss of Beech. The key role of Neonectria coccinea in causing bark necroses and the loss of vitality in beech was confirmed because the tested strain induced large lesions on the beech saplings.

scholarly journals Absence of Stabilizing Mutations of β-Catenin Encoded by CTNNB1 Exon 3 in a Large Series of Sporadic Parathyroid Adenomas

2007 ◽  
Vol 92 (4) ◽  
pp. 1564-1566 ◽  
Author(s):  
Jessica Costa-Guda ◽  
Andrew Arnold
Keyword(s):  
Wnt Signaling ◽  
Molecular Mechanisms ◽  
Wnt Signaling Pathway ◽  
Tumor Formation ◽  
Large Series ◽  
Primary Role ◽  
Parathyroid Tumor ◽  
Direct Dna Sequencing ◽  
Parathyroid Adenomas

Abstract Context: The molecular mechanisms underlying the pathogenesis of sporadic parathyroid adenomas are incompletely understood. Dysfunction of the Wnt signaling pathway is an established pathogenetic contributor to human tumorigenesis and, recently, the role of stabilizing mutations in β-catenin, a cause of abnormal Wnt signaling, has been examined in parathyroid tumors with conflicting results. Objective: The objective of the present study was to determine the frequency of stabilizing mutations in exon 3 of CTNNB1, encoding β-catenin, in a large series of parathyroid adenomas. Patients and Design: Ninety-seven sporadic parathyroid adenomas were examined for mutations in exon 3 of CTNNB1 by direct DNA sequencing. Results: No mutations were identified in any of the adenomas. Conclusions: The absence of stabilizing mutations of β-catenin, including the previously reported S37A, encoded in CTNNB1 exon 3 among 97 tumors suggests that such mutations contribute rarely if at all to the development of sporadic parathyroid adenomas. A primary role for abnormal Wnt signaling in parathyroid tumor formation remains to be established.

Site of Lysosome Production During Hepatic Injury

1969 ◽  
Vol 27 ◽  
pp. 348-349
Author(s):  
Nalin J. Unakar
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mouse Liver ◽  
Hepatic Injury ◽  
Close Approximation ◽  
Experimental Conditions ◽  
Toxic Injury

The increased number of lysosomes as well as the close approximation of lysosomes to the Golgi apparatus in tissue under variety of experimental conditions is commonly observed. These observations suggest Golgi involvement in lysosomal production. The role of the Golgi apparatus in the production of lysosomes in mouse liver was studied by electron microscopy of liver following toxic injury by CCI4.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

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