scholarly journals Analysis of Kytococcus sedentarius Strain Isolated from a Dehumidifier Operating in a University Lecture Theatre: Systems for Aerobic Respiration, Resisting Osmotic Stress, and Sensing Nitric Oxide

2021 ◽  
pp. 1-11
Author(s):  
Meshari Ahmed Alhadlaq ◽  
Jeffrey Green ◽  
Bassam K. Kudhair
Keyword(s):  
Nitric Oxide ◽  
Growth Conditions ◽  
Sigma Factors ◽  
Regulatory Proteins ◽  
Erythromycin Resistance ◽  
Iron Sulfur ◽  
Transport Chain ◽  
Heterologous System ◽  
Phenotypic Characterisation ◽  
Lecture Theatre

A strain of Kytococcus sedentarius was isolated from a dehumidifier operating in a university lecture theatre. Genome analysis and phenotypic characterisation showed that this strain, K. sedentarius MBB13, was a moderately halotolerant aerobe with a branched aerobic electron transport chain and genes that could contribute to erythromycin resistance. The major compatible solute was glycine betaine, with ectoine and proline being deployed at higher osmolarities. Actinobacteria possess multiple WhiB-like (Wbl) regulatory proteins, and K. sedentarius MBB13 has four (WhiB1, WhiB2, WhiB3, and WhiB7). Wbls are iron-sulfur proteins that regulate gene expression through interactions with RNA polymerase sigma factors and/or other regulatory proteins. Bacterial two-hybrid analyses suggested that WhiB1 and WhiB2, but not WhiB3 and WhiB7, interact with the C-terminal domain of the major sigma factor, σA; no interaction was detected between any of the Wbl proteins and the only alternative sigma factors, σB, σH, or σJ. The interaction between σA and WhiB1 or WhiB2 was disrupted in a heterologous system under growth conditions that produce nitric oxide and the iron-sulfur clusters of the isolated WhiB1 and WhiB2 proteins reacted with nitric oxide. Thus, K. sedentarius strain exhibits the major phenotypic characteristics of the type strain and a comprehensive examination of the interactions between its four Wbl proteins and four sigma factors suggested that the Wbl proteins all operate through interaction with σA.

scholarly journals Multiple Sense and Antisense Promoters Contribute to the Regulated Expression of the isc-suf Operon for Iron-Sulfur Cluster Assembly in Rhodobacter

2019 ◽  
Vol 7 (12) ◽  
pp. 671 ◽  
Author(s):  
Xin Nie ◽  
Bernhard Remes ◽  
Gabriele Klug
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Photosynthetic Electron Transport ◽  
Regulatory Proteins ◽  
Cluster Assembly ◽  
Iron Sulfur Cluster ◽  
Iron Sulfur Clusters ◽  
Sulfur Cluster ◽  
Iron Sulfur ◽  
Photosynthetic Complexes ◽  
The One

A multitude of biological functions relies on iron-sulfur clusters. The formation of photosynthetic complexes goes along with an additional demand for iron-sulfur clusters for bacteriochlorophyll synthesis and photosynthetic electron transport. However, photooxidative stress leads to the destruction of iron-sulfur clusters, and the released iron promotes the formation of further reactive oxygen species. A balanced regulation of iron-sulfur cluster synthesis is required to guarantee the supply of this cofactor, on the one hand, but also to limit stress, on the other hand. The phototrophic alpha-proteobacterium Rhodobacter sphaeroides harbors a large operon for iron-sulfur cluster assembly comprising the iscRS and suf genes. IscR (iron-sulfur cluster regulator) is an iron-dependent regulator of isc-suf genes and other genes with a role in iron metabolism. We applied reporter gene fusions to identify promoters of the isc-suf operon and studied their activity alone or in combination under different conditions. Gel-retardation assays showed the binding of regulatory proteins to individual promoters. Our results demonstrated that several promoters in a sense and antisense direction influenced isc-suf expression and the binding of the IscR, Irr, and OxyR regulatory proteins to individual promoters. These findings demonstrated a complex regulatory network of several promoters and regulatory proteins that helped to adjust iron-sulfur cluster assembly to changing conditions in Rhodobacter sphaeroides.

scholarly journals Pleurotus albidus Modulates Mitochondrial Metabolism Disrupted by Hyperglycaemia in EA.hy926 Endothelial Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Gabriela Gambato ◽  
Elisa Maria Pavão ◽  
Gabriela Chilanti ◽  
Roselei Claudete Fontana ◽  
Mirian Salvador ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Mitochondrial Dysfunction ◽  
Complex I ◽  
Electron Transport Chain ◽  
Mitochondrial Disorder ◽  
Antioxidant Enzyme Activities ◽  
Ros Production ◽  
Oxygen Species ◽  
Transport Chain

Hyperglycaemia exacerbates the production of reactive oxygen species (ROS), contributing to the multiple complications associated with diabetes. Mitochondrial dysfunction is also known to be associated with diabetes. Therefore, the aim of this work was to study the effect of Pleurotus albidus extract on the mitochondrial dysfunction induced by hyperglycaemia in EA.hy926 endothelial cells. The results showed that P. albidus treatment prevented the increase in the activity of complex I of the electron transport chain and minimized the ROS production induced by hyperglycaemia. In addition, the extract minimized oxidative damage to lipids and proteins, caused an imbalance in the antioxidant enzyme activities of superoxide dismutase and catalase, and decreased the nitric oxide levels induced by hyperglycaemia. These data contribute to our understanding of the mitochondrial disorder induced by hyperglycaemia as well as establishing the conditions required to minimize these alterations.

scholarly journals Nitric Oxide Overproduction by cue1 Mutants Differs on Developmental Stages and Growth Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1484 ◽  
Author(s):  
Tamara Lechón ◽  
Luis Sanz ◽  
Inmaculada Sánchez-Vicente ◽  
Oscar Lorenzo
Keyword(s):  
Nitric Oxide ◽  
Carbon Metabolism ◽  
Root Elongation ◽  
Developmental Stages ◽  
Primary Root ◽  
Carbon Sources ◽  
Growth Conditions ◽  
No Production

The cue1 nitric oxide (NO) overproducer mutants are impaired in a plastid phosphoenolpyruvate/phosphate translocator, mainly expressed in Arabidopsis thaliana roots. cue1 mutants present an increased content of arginine, a precursor of NO in oxidative synthesis processes. However, the pathways of plant NO biosynthesis and signaling have not yet been fully characterized, and the role of CUE1 in these processes is not clear. Here, in an attempt to advance our knowledge regarding NO homeostasis, we performed a deep characterization of the NO production of four different cue1 alleles (cue1-1, cue1-5, cue1-6 and nox1) during seed germination, primary root elongation, and salt stress resistance. Furthermore, we analyzed the production of NO in different carbon sources to improve our understanding of the interplay between carbon metabolism and NO homeostasis. After in vivo NO imaging and spectrofluorometric quantification of the endogenous NO levels of cue1 mutants, we demonstrate that CUE1 does not directly contribute to the rapid NO synthesis during seed imbibition. Although cue1 mutants do not overproduce NO during germination and early plant development, they are able to accumulate NO after the seedling is completely established. Thus, CUE1 regulates NO homeostasis during post-germinative growth to modulate root development in response to carbon metabolism, as different sugars modify root elongation and meristem organization in cue1 mutants. Therefore, cue1 mutants are a useful tool to study the physiological effects of NO in post-germinative growth.

scholarly journals A Cross-linking Mass Spectrometry Approach Defines Protein Interactions in Yeast Mitochondria

2020 ◽  
Vol 19 (7) ◽  
pp. 1161-1178 ◽  
Author(s):  
Andreas Linden ◽  
Markus Deckers ◽  
Iwan Parfentev ◽  
Ralf Pflanz ◽  
Bettina Homberg ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Isotopic Labeling ◽  
Growth Conditions ◽  
Cross Linking ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Protein Protein Interactions ◽  
Copy Numbers ◽  
Transport Chain ◽  
Quantitative Changes

Protein cross-linking and the analysis of cross-linked peptides by mass spectrometry is currently receiving much attention. Not only is this approach applied to isolated complexes to provide information about spatial arrangements of proteins, but it is also increasingly applied to entire cells and their organelles. As in quantitative proteomics, the application of isotopic labeling further makes it possible to monitor quantitative changes in the protein-protein interactions between different states of a system. Here, we cross-linked mitochondria from Saccharomyces cerevisiae grown on either glycerol- or glucose-containing medium to monitor protein-protein interactions under non-fermentative and fermentative conditions. We investigated qualitatively the protein-protein interactions of the 400 most abundant proteins applying stringent data-filtering criteria, i.e. a minimum of two cross-linked peptide spectrum matches and a cut-off in the spectrum scoring of the used search engine. The cross-linker BS3 proved to be equally suited for connecting proteins in all compartments of mitochondria when compared with its water-insoluble but membrane-permeable derivative DSS. We also applied quantitative cross-linking to mitochondria of both the growth conditions using stable-isotope labeled BS3. Significant differences of cross-linked proteins under glycerol and glucose conditions were detected, however, mainly because of the different copy numbers of these proteins in mitochondria under both the conditions. Results obtained from the glycerol condition indicate that the internal NADH:ubiquinone oxidoreductase Ndi1 is part of an electron transport chain supercomplex. We have also detected several hitherto uncharacterized proteins and identified their interaction partners. Among those, Min8 was found to be associated with cytochrome c oxidase. BN-PAGE analyses of min8Δ mitochondria suggest that Min8 promotes the incorporation of Cox12 into cytochrome c oxidase.

scholarly journals Nitrosylation of Nitric-Oxide-Sensing Regulatory Proteins Containing [4Fe-4S] Clusters Gives Rise to Multiple Iron-Nitrosyl Complexes

2016 ◽  
Vol 128 (47) ◽  
pp. 14795-14799 ◽  
Author(s):  
Pauline N. Serrano ◽  
Hongxin Wang ◽  
Jason C. Crack ◽  
Christopher Prior ◽  
Matthew I. Hutchings ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Regulatory Proteins ◽  
Nitrosyl Complexes ◽  
Iron Nitrosyl ◽  
Iron Nitrosyl Complexes

Progesterone and modulation of endothelium-dependent responses in canine coronary arteries

1991 ◽  
Vol 261 (4) ◽  
pp. R1022-R1027 ◽  
Author(s):  
V. M. Miller ◽  
P. M. Vanhoutte
Keyword(s):  
Nitric Oxide ◽  
Coronary Arteries ◽  
Chronic Treatment ◽  
Isometric Force ◽  
Calcium Ionophore ◽  
Treated Group ◽  
Regulatory Proteins ◽  
Adrenergic Agonist ◽  
Messenger System ◽  
Guanine Nucleotide Regulatory Proteins

Chronic treatment with estrogens enhances some endothelium-dependent relaxations. Whether or not progesterone would exert a similar effect is unknown. Experiments were designed to determine the effect of chronic treatment with progesterone on endothelium-dependent responses. Adult female dogs were ovariectomized and pellets containing carrier substance, estrogen, progesterone, or estrogen plus progesterone were implanted subcutaneously. After 14-21 days coronary arteries were removed, cut into rings, and suspended for the measurement of isometric force in organ chambers in the presence of indomethacin. Endothelium-dependent relaxations to ADP, bradykinin, or the calcium ionophore did not differ among groups. However, relaxations to acetylcholine and to the alpha 2-adrenergic agonist BHT-920 were greater in the estrogen-treated group than in the estrogen plus progesterone-treated group. In rings without endothelium, relaxations to nitric oxide and isoproterenol did not differ among groups. However, relaxations of the smooth muscle to ADP were greater in the progesterone-treated group than in the progesterone plus estrogen group. These results suggest that progesterone alone minimally affects endothelium-dependent responses. However, progesterone seems to antagonize the stimulatory effects of estrogen on two endothelium-dependent responses that are associated with pertussis toxin-sensitive guanine nucleotide regulatory proteins and the production of nitric oxide. These studies suggest that a specific receptor/second messenger system can be modulated by female reproductive steroid hormones.

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