scholarly journals Mutational Analysis of a Role for Salicylic Acid in Iron Metabolism of Mycobacterium smegmatis

2000 ◽  
Vol 182 (2) ◽  
pp. 264-271 ◽  
Author(s):  
Tadepalli Adilakshmi ◽  
Peter D. Ayling ◽  
Colin Ratledge
Keyword(s):  
Salicylic Acid ◽  
Iron Metabolism ◽  
Mycobacterium Smegmatis ◽  
Mutational Analysis ◽  
Cell Envelope ◽  
Iron Status ◽  
Growth Conditions ◽  
Receptor Protein ◽  
Signal Molecule ◽  
Additional Function

ABSTRACT The role of salicylic acid in iron metabolism was examined in two wild-type strains (mc2155 and NCIMB 8548) and three mutant strains (mc21292 [lacking exochelin], SM3 [lacking iron-dependent repressor protein IdeR] and S99 [a salicylate-requiring auxotroph derived in this study]) ofMycobacterium smegmatis. Synthesis of salicylate in SM3 was derepressed even in the presence of iron, as was synthesis of the siderophores exochelin, mycobactin, and carboxymycobactin. S99 was dependent on salicylate for growth and failed to grow with the three ferrisiderophores, suggesting that salicylate fulfills an additional function(s) other than being a precursor of mycobactin and carboxymycobactin. Salicylic acid at 100 μg/ml repressed the formation of a 29-kDa cell envelope protein (putative exochelin receptor protein) in S99 grown both iron deficiently and iron sufficiently. In contrast, synthesis of this protein was affected only under iron-limited conditions in the parent strain, mc2155, and remained unaltered in SM3, suggesting an interaction between the IdeR protein and salicylate. Thus, salicylate may also function as a signal molecule for recognition of cellular iron status. Growth of all strains and mutants with p-aminosalicylate (PAS) at 100 μg/ml increased salicylate accumulation between three- and eightfold under both iron-limited and iron-sufficient growth conditions and decreased mycobactin accumulation by 40 to 80% but increased carboxymycobactin accumulation by 50 to 55%. Thus, although PAS inhibited salicylate conversion to mycobactin, presumptively by blocking salicylate AMP kinase, PAS also interferes with the additional functions of salicylate, as its effect was heightened in S99 when the salicylate concentration was minimal.

scholarly journals luxS-Dependent Gene Regulation in Escherichia coli K-12 Revealed by Genomic Expression Profiling

2005 ◽  
Vol 187 (24) ◽  
pp. 8350-8360 ◽  
Author(s):  
Liang Wang ◽  
Jun Li ◽  
John C. March ◽  
James J. Valdes ◽  
William E. Bentley
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Growth Conditions ◽  
Receptor Protein ◽  
Metabolic Enzyme ◽  
Signal Molecule ◽  
E Coli ◽  
Induced Genes ◽  
K 12

ABSTRACT The bacterial quorum-sensing autoinducer 2 (AI-2) has received intense interest because the gene for its synthase, luxS, is common among a large number of bacterial species. We have identified luxS-controlled genes in Escherichia coli under two different growth conditions using DNA microarrays. Twenty-three genes were affected by luxS deletion in the presence of glucose, and 63 genes were influenced by luxS deletion in the absence of glucose. Minimal overlap among these gene sets suggests the role of luxS is condition dependent. Under the latter condition, the metE gene, the lsrACDBFG operon, and the flanking genes of the lsr operon (lsrR, lsrK, tam, and yneE) were among the most significantly induced genes by luxS. The E. coli lsr operon includes an additional gene, tam, encoding an S-adenosyl-l-methionine-dependent methyltransferase. Also, lsrR and lsrK belong to the same operon, lsrRK, which is positively regulated by the cyclic AMP receptor protein and negatively regulated by LsrR. lsrK is additionally transcribed by a promoter between lsrR and lsrK. Deletion of luxS was also shown to affect genes involved in methionine biosynthesis, methyl transfer reactions, iron uptake, and utilization of carbon. It was surprising, however, that so few genes were affected by luxS deletion in this E. coli K-12 strain under these conditions. Most of the highly induced genes are related to AI-2 production and transport. These data are consistent with the function of LuxS as an important metabolic enzyme but appear not to support the role of AI-2 as a true signal molecule for E. coli W3110 under the investigated conditions.

scholarly journals Iron status influences non-alcoholic fatty liver disease in obesity through the gut microbiome

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jordi Mayneris-Perxachs ◽  
Marina Cardellini ◽  
Lesley Hoyles ◽  
Jèssica Latorre ◽  
Francesca Davato ◽  
...  
Keyword(s):  
Serum Ferritin ◽  
Iron Metabolism ◽  
Gut Microbiome ◽  
Fatty Liver Disease ◽  
Iron Status ◽  
Liver Fat ◽  
Alcoholic Fatty Liver ◽  
Fat Accumulation ◽  
Glycine Transporters ◽  
Alcoholic Fatty Liver Disease

Abstract Background The gut microbiome and iron status are known to play a role in the pathophysiology of non-alcoholic fatty liver disease (NAFLD), although their complex interaction remains unclear. Results Here, we applied an integrative systems medicine approach (faecal metagenomics, plasma and urine metabolomics, hepatic transcriptomics) in 2 well-characterised human cohorts of subjects with obesity (discovery n = 49 and validation n = 628) and an independent cohort formed by both individuals with and without obesity (n = 130), combined with in vitro and animal models. Serum ferritin levels, as a markers of liver iron stores, were positively associated with liver fat accumulation in parallel with lower gut microbial gene richness, composition and functionality. Specifically, ferritin had strong negative associations with the Pasteurellaceae, Leuconostocaceae and Micrococcaea families. It also had consistent negative associations with several Veillonella, Bifidobacterium and Lactobacillus species, but positive associations with Bacteroides and Prevotella spp. Notably, the ferritin-associated bacterial families had a strong correlation with iron-related liver genes. In addition, several bacterial functions related to iron metabolism (transport, chelation, heme and siderophore biosynthesis) and NAFLD (fatty acid and glutathione biosynthesis) were also associated with the host serum ferritin levels. This iron-related microbiome signature was linked to a transcriptomic and metabolomic signature associated to the degree of liver fat accumulation through hepatic glucose metabolism. In particular, we found a consistent association among serum ferritin, Pasteurellaceae and Micrococcacea families, bacterial functions involved in histidine transport, the host circulating histidine levels and the liver expression of GYS2 and SEC24B. Serum ferritin was also related to bacterial glycine transporters, the host glycine serum levels and the liver expression of glycine transporters. The transcriptomic findings were replicated in human primary hepatocytes, where iron supplementation also led to triglycerides accumulation and induced the expression of lipid and iron metabolism genes in synergy with palmitic acid. We further explored the direct impact of the microbiome on iron metabolism and liver fact accumulation through transplantation of faecal microbiota into recipient’s mice. In line with the results in humans, transplantation from ‘high ferritin donors’ resulted in alterations in several genes related to iron metabolism and fatty acid accumulation in recipient’s mice. Conclusions Altogether, a significant interplay among the gut microbiome, iron status and liver fat accumulation is revealed, with potential significance for target therapies.

scholarly journals The Mycobacteriophage Ms6 LysB N-Terminus Displays Peptidoglycan Binding Affinity

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1377
Author(s):  
Adriano M. Gigante ◽  
Francisco Olivença ◽  
Maria João Catalão ◽  
Paula Leandro ◽  
José Moniz-Pereira ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Fluorescent Protein ◽  
Cell Envelope ◽  
Structural Similarity ◽  
Lytic Cycle ◽  
Specific Lysis ◽  
Double Stranded Dna ◽  
The Family ◽  
N Terminus ◽  
Green Fluorescent

Double-stranded DNA bacteriophages end their lytic cycle by disrupting the host cell envelope, which allows the release of the virion progeny. Each phage must synthesize lysis proteins that target each cell barrier to phage release. In addition to holins, which permeabilize the cytoplasmic membrane, and endolysins, which disrupt the peptidoglycan (PG), mycobacteriophages synthesize a specific lysis protein, LysB, capable of detaching the outer membrane from the complex cell wall of mycobacteria. The family of LysB proteins is highly diverse, with many members presenting an extended N-terminus. The N-terminal region of mycobacteriophage Ms6 LysB shows structural similarity to the PG-binding domain (PGBD) of the φKZ endolysin. A fusion of this region with enhanced green fluorescent protein (Ms6LysBPGBD-EGFP) was shown to bind to Mycobacterium smegmatis, Mycobacterium vaccae, Mycobacterium bovis BGC and Mycobacterium tuberculosis H37Ra cells pretreated with SDS or Ms6 LysB. In pulldown assays, we demonstrate that Ms6 LysB and Ms6LysBPGBD-EGFP bind to purified peptidoglycan of M. smegmatis, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis, demonstrating affinity to PG of the A1γ chemotype. An infection assay with an Ms6 mutant producing a truncated version of LysB lacking the first 90 amino acids resulted in an abrupt lysis. These results clearly demonstrate that the N-terminus of Ms6 LysB binds to the PG.

Acetyl salicylic acid alleviates chilling-induced damage in muskmelon seedlings

2007 ◽  
Vol 87 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Ahmet Korkmaz ◽  
Murat Uzunlu ◽  
Ali Riza Demirkiran
Keyword(s):  
Salicylic Acid ◽  
Cucumis Melo ◽  
Chilling Stress ◽  
Foliar Spray ◽  
Dry Weight ◽  
Acetyl Salicylic Acid ◽  
Signal Molecule ◽  
Stress Indicator ◽  
Shoot Dry Weight ◽  
Significant Difference

Salicylic acid (SA) is a common plant-produced signal molecule that is responsible for inducing tolerance to a number of biotic and abiotic stresses. An experiment was, therefore, conducted to test whether acetyl salicylic acid (ASA) application at various concentrations through seed immersion or foliar spray would protect muskmelon [Cucumis melo L. (Reticulatus Group)] seedlings subjected to chilling stress. Twenty-one-day-old plants pre-treated with ASA (0, 0.1, 0.25, 0.50 or 1.0 mM) were subjected to chilling stress for 72 h at 3 ± 0.5°C. ASA, applied either through seed immersion or foliar spray, was effective within the range of 0.1 to 1 mM in inducing tolerance to chilling stress in muskmelon seedlings; however, there was no significant difference between application methods. ASA significantly and curvilinearly affected all seedling growth and stress indicator variables tested except shoot dry weight. The best protection was obtained from seedlings pre-treated with 0.5 mM ASA. The highest ASA concentration used was slightly less effective in providing chilling stress protection. Even though both methods provided similar means of protection, due to its simplicity and practicality, immersion of muskmelon seeds prior to sowing in 0.5 mM ASA would be a more desirable method to induce tolerance to chilling stress. Key words: Cucumis melo, aspirin, chilling stress tolerance, gas exchange, electrolyte leakage

scholarly journals Disruption of the SucT acyltransferase in Mycobacterium smegmatis abrogates succinylation of cell envelope polysaccharides

2019 ◽  
Vol 294 (26) ◽  
pp. 10325-10335 ◽  
Author(s):  
Zuzana Palčeková ◽  
Shiva K. Angala ◽  
Juan Manuel Belardinelli ◽  
Haig A. Eskandarian ◽  
Maju Joe ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Cell Envelope

scholarly journals Effect of salicylic acid on pre-transplant acclimatization of native tomato populations

2018 ◽  
Vol 36 (4) ◽  
pp. 480-485
Author(s):  
Wilberth A Poot-Poot ◽  
Rafael Delgado-Martínez ◽  
Sergio Castro-Nava ◽  
Ma Teresa Segura-Martínez ◽  
Alejandro Carreón-Pérez ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Growth And Development ◽  
Growth Parameters ◽  
Field Capacity ◽  
Dry Weight ◽  
Growth Conditions ◽  
Peat Moss ◽  
Hypocotyl Length ◽  
Cell Processes ◽  
Recorded Data

ABSTRACT The aim of this study was to evaluate the effect of salicylic acid (SA) application on pre-transplant acclimatization of native populations of tomato. SA is a growth regulator that modifies plant growth and development by inducing changes in cell processes, physiology and morphology. Five populations of native tomato were sown in polystyrene trays. Peat moss was used as substrate and plants were maintained at field capacity continuously. After emergence, seedlings were applied during three weeks with different concentration of SA (0.0, 0.01, 0.1, 0.5 and 1.0 μM). A completely random experimental design was used with five replications per treatment. The growth parameters evaluated were height, stem diameter, number of leaves, hypocotyl length, shoot fresh and dry weight (leaves and stem), and root length and fresh and dry weight. An analysis of variance was carried out, and means were compared with the Tukey test (5%) using SAS statistical software. The recorded data show that pre-transplant seedlings of each of the evaluated populations responded significantly (P=0.01) to the SA treatments. Also, the comparison of means of each of the factors under study showed positive changes. With the concentrations of 0.5 and 0.1 μM SA, higher values of the studied variables were obtained than with the concentrations 0.01 and 1.0 μM SA. The native tomato populations sprayed with SA at concentrations of 0.5 and 0.1 μM responded positively in terms of seedling growth and development. Based on these findings, SA treatments can help acclimatize and present better growth conditions to the seedlings before being transplanted.

scholarly journals Application of Endophytic Bacillus subtilis and Salicylic Acid to Improve Wheat Growth and Tolerance under Combined Drought and Fusarium Root Rot Stresses

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1343 ◽  
Author(s):  
Oksana Lastochkina ◽  
Darya Garshina ◽  
Chulpan Allagulova ◽  
Kristina Fedorova ◽  
Igor Koryakov ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Salicylic Acid ◽  
Root Rot ◽  
Endophytic Bacteria ◽  
Wheat Yield ◽  
Maximum Effect ◽  
Subtilis Strain ◽  
Signal Molecule ◽  
Wheat Growth ◽  
Root And Shoot Length

In nature, plants are constantly exposed to a varied abiotic and biotic stresses or their combinations, limiting the productivity of major crops, including wheat. Combinations of drought and soil-borne Fusarium-instigated diseases are the most common combinations of stresses, significantly reducing wheat yield around the world. Here, were analyzed the potential of application of endophytic bacteria Bacillus subtilis (strain 10–4) together with the natural signal molecule salicylic acid (SA) to improve growth and tolerance of Triticum aestivum L. (wheat) plants under combined drought and Fusarium culmorum-instigated root rot (FRR) stresses. It was revealed that pre-sowing treatment with B. subtilis 10–4, SA, and B. subtilis 10–4 + SA, both under normal and combined drought conditions, notably reduced (by 50–80% or more) the incidence of FRR development in wheat plants, with the most notable effect for B. subtilis 10–4 + SA (wherein disease symptoms were almost absent). Moreover, B. subtilis 10–4, SA, and especially B. subtilis 10–4 + SA increased plant growth (root and shoot length, fresh and dry biomass) under normal (up to 20–50%), drought (up to 15–40%), FRR (up to 15–30%), and combined drought + FRR stresses (up to 20%), with the maximum effect for B. subtilis 10–4 + SA. Additionally, B. subtilis 10–4, SA, and B. subtilis 10–4 + SA decreased stress (drought, FRR, and combined drought + FRR)-instigated lipid peroxidation and osmotic damages of plant cells. The findings indicate that endophytic bacteria B. subtilis 10–4 alone and in a mixture with SA may be used as an effective eco-friendly agent to improve wheat growth and tolerance under the influence of drought, FRR, and combinations of these stresses.

scholarly journals Inherited microcytic anemias

Hematology ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 465-470
Author(s):  
Maria Domenica Cappellini ◽  
Roberta Russo ◽  
Immacolata Andolfo ◽  
Achille Iolascon
Keyword(s):  
Iron Deficiency ◽  
Blood Cell ◽  
Iron Metabolism ◽  
Red Blood Cell ◽  
Iron Status ◽  
Transferrin Saturation ◽  
Microcytic Anemia ◽  
Deficiency Anemia ◽  
Mean Corpuscular Hemoglobin ◽  
Distribution Width

Abstract Inherited microcytic anemias can be broadly classified into 3 subgroups: (1) defects in globin chains (hemoglobinopathies or thalassemias), (2) defects in heme synthesis, and (3) defects in iron availability or iron acquisition by the erythroid precursors. These conditions are characterized by a decreased availability of hemoglobin (Hb) components (globins, iron, and heme) that in turn causes a reduced Hb content in red cell precursors with subsequent delayed erythroid differentiation. Iron metabolism alterations remain central to the diagnosis of microcytic anemia, and, in general, the iron status has to be evaluated in cases of microcytosis. Besides the very common microcytic anemia due to acquired iron deficiency, a range of hereditary abnormalities that result in actual or functional iron deficiency are now being recognized. Atransferrinemia, DMT1 deficiency, ferroportin disease, and iron-refractory iron deficiency anemia are hereditary disorders due to iron metabolism abnormalities, some of which are associated with iron overload. Because causes of microcytosis other than iron deficiency should be considered, it is important to evaluate several other red blood cell and iron parameters in patients with a reduced mean corpuscular volume (MCV), including mean corpuscular hemoglobin, red blood cell distribution width, reticulocyte hemoglobin content, serum iron and serum ferritin levels, total iron-binding capacity, transferrin saturation, hemoglobin electrophoresis, and sometimes reticulocyte count. From the epidemiological perspective, hemoglobinopathies/thalassemias are the most common forms of hereditary microcytic anemia, ranging from inconsequential changes in MCV to severe anemia syndromes.

Sign in / Sign up

Export Citation Format

Share Document