CYBB, an NADPH-oxidase gene: restricted diversity in humans and evidence for differential long-term purifying selection on transmembrane and cytosolic domains

2008 ◽  
Vol 29 (5) ◽  
pp. 623-632 ◽  
Author(s):  
Eduardo Tarazona-Santos ◽  
Toralf Bernig ◽  
Laurie Burdett ◽  
Wagner C.S. Magalhaes ◽  
Cristina Fabbri ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Purifying Selection ◽  
Oxidase Gene ◽  
Cytosolic Domains

scholarly journals Diversity and evolution of surface polysaccharide synthesis loci in Enterobacteriales

2019 ◽  
Author(s):  
Kathryn E. Holt ◽  
Florent Lassalle ◽  
Kelly L. Wyres ◽  
Ryan Wick ◽  
Rafal J. Mostowy
Keyword(s):  
Evolutionary Dynamics ◽  
Bacterial Species ◽  
Purifying Selection ◽  
Evolutionary Forces ◽  
Polysaccharide Synthesis ◽  
Surface Polysaccharides ◽  
Surface Polysaccharide ◽  
Selective Preservation ◽  
Multiple Species

Bacterial capsules and lipopolysaccharides are diverse surface polysaccharides (SPs) that serve as the frontline for interactions with the outside world. While SPs can evolve rapidly, their diversity and evolutionary dynamics across different taxonomic scales has not been investigated in detail. Here, we focused on the bacterial order Enterobacteriales (including the medically-relevant Enterobacteriaceae), to carry out comparative genomics of two SP locus synthesis regions, cps and kps, using 27,334 genomes from 45 genera. We identified high-quality cps loci in 22 genera and kps in 11 genera, around 4% of which were detected in multiple species. We found SP loci to be highly dynamic genetic entities: their evolution was driven by high rates of horizontal gene transfer (HGT), both of whole loci and component genes, and relaxed purifying selection, yielding large repertoires of SP diversity. In spite of that, we found the presence of (near-)identical locus structures in distant taxonomic backgrounds that could not be explained by recent exchange, pointing to long-term selective preservation of locus structures in some populations. Our results reveal differences in evolutionary dynamics driving SP diversity within different bacterial species, with lineages of Escherichia coli, Enterobacter hormachei and Klebsiella aerogenes most likely to share SP loci via recent exchange; and lineages of Salmonella enterica, Citrobacter sakazakii and Serratia marcescens most likely to share SP loci via other mechanisms such as long-term preservation. Overall, the evolution of SP loci in Enterobacteriales is driven by a range of evolutionary forces and their dynamics and relative importance varies between different species.

Mechanisms of severe acute intermittent hypoxia-induced phrenic long-term facilitation

2021 ◽  
Vol 125 (4) ◽  
pp. 1146-1156
Author(s):  
Nicole L. Nichols ◽  
Gordon S. Mitchell
Keyword(s):  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Intermittent Hypoxia ◽  
Nadph Oxidase Activity ◽  
Complex Interactions ◽  
Long Term Facilitation ◽  
Erk Activity

Distinct mechanisms give rise to pLTF induced by moderate and severe AIH. We demonstrate that, unlike moderate AIH, severe AIH-induced pLTF requires EPAC and PI3K/Akt and is marginally constrained by NADPH oxidase activity. Surprisingly, sAIH-induced pLTF requires MEK/ERK activity similar to moderate AIH-induced pLTF and is reduced by PKA inhibition. We suggest sAIH-induced pLTF arises from complex interactions between dominant mechanisms characteristic of moderate versus severe AIH-induced pLTF.

scholarly journals Long-term experimental evolution reveals purifying selection on piRNA-mediated control of transposable element expression

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Ulfar Bergthorsson ◽  
Caroline J. Sheeba ◽  
Anke Konrad ◽  
Tony Belicard ◽  
Toni Beltran ◽  
...  
Keyword(s):  
Natural Selection ◽  
Transcriptional Activation ◽  
Small Rnas ◽  
Active Regions ◽  
Purifying Selection ◽  
Ancestral Population ◽  
Sequence Context ◽  
C Elegans ◽  
Population Sizes

Abstract Background Transposable elements (TEs) are an almost universal constituent of eukaryotic genomes. In animals, Piwi-interacting small RNAs (piRNAs) and repressive chromatin often play crucial roles in preventing TE transcription and thus restricting TE activity. Nevertheless, TE content varies widely across eukaryotes and the dynamics of TE activity and TE silencing across evolutionary time is poorly understood. Results Here, we used experimentally evolved populations of C. elegans to study the dynamics of TE expression over 409 generations. The experimental populations were evolved at population sizes of 1, 10 and 100 individuals to manipulate the efficiency of natural selection versus genetic drift. We demonstrate increased TE expression relative to the ancestral population, with the largest increases occurring in the smallest populations. We show that the transcriptional activation of TEs within active regions of the genome is associated with failure of piRNA-mediated silencing, whilst desilenced TEs in repressed chromatin domains retain small RNAs. Additionally, we find that the sequence context of the surrounding region influences the propensity of TEs to lose silencing through failure of small RNA-mediated silencing. Conclusions Our results show that natural selection in C. elegans is responsible for maintaining low levels of TE expression, and provide new insights into the epigenomic features responsible.

scholarly journals Diapocynin, an NADPH oxidase inhibitor, counteracts diisopropylfluorophosphate‐induced long‐term neurotoxicity in the rat model

2020 ◽  
Vol 1479 (1) ◽  
pp. 75-93 ◽  
Author(s):  
Marson Putra ◽  
Meghan Gage ◽  
Shaunik Sharma ◽  
Cara Gardner ◽  
Grace Gasser ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Rat Model ◽  
Oxidase Inhibitor ◽  
Nadph Oxidase Inhibitor

scholarly journals C-Terminal Region of Plant Ferredoxin-Like Protein Is Required to Enhance Resistance to Bacterial Disease in Arabidopsis thaliana

2011 ◽  
Vol 101 (6) ◽  
pp. 741-749 ◽  
Author(s):  
Yi-Hsien Lin ◽  
Hsiang-En Huang ◽  
Yen-Ru Chen ◽  
Pei-Luan Liao ◽  
Ching-Lian Chen ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Transgenic Plants ◽  
Nadph Oxidase ◽  
Pseudomonas Syringae ◽  
Induced Defense ◽  
Defense Responses ◽  
Bacterial Disease ◽  
Oxidase Gene ◽  
Induced Defense Responses ◽  
Resistance To Ralstonia Solanacearum

Protein phosphorylation is an important biological process associated with elicitor-induced defense responses in plants. In a previous report, we described how plant ferredoxin-like protein (PFLP) in transgenic plants enhances resistance to bacterial pathogens associated with the hypersensitive response (HR). PFLP possesses a putative casein kinase II phosphorylation (CK2P) site at the C-terminal in which phosphorylation occurs rapidly during defense response. However, the contribution of this site to the enhancement of disease resistance and the intensity of HR has not been clearly demonstrated. In this study, we generated two versions of truncated PFLP, PEC (extant CK2P site) and PDC (deleted CK2P site), and assessed their ability to trigger HR through harpin (HrpZ) derived from Pseudomonas syringae as well as their resistance to Ralstonia solanacearum. In an infiltration assay of HrpZ, PEC intensified harpin-mediated HR; however, PDC negated this effect. Transgenic plants expressing these versions indicate that nonphosphorylated PFLP loses its ability to induce HR or enhance disease resistance against R. solanacearum. Interestingly, the CK2P site of PFLP is required to induce the expression of the NADPH oxidase gene, AtrbohD, which is a reactive oxygen species producing enzyme. This was further confirmed by evaluating the HR on NADPH oxidase in mutants of Arabidopsis. As a result, we have concluded that the CK2P site is required for the phosphorylation of PFLP to enhance disease resistance.

Metal-specific and NADPH oxidase dependent changes in lipoxygenase and NADPH oxidase gene expression in Arabidopsis thaliana exposed to cadmium or excess copper

2010 ◽  
Vol 37 (6) ◽  
pp. 532 ◽  
Author(s):  
Tony Remans ◽  
Kelly Opdenakker ◽  
Karen Smeets ◽  
Dennis Mathijsen ◽  
Jaco Vangronsveld ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Arabidopsis Thaliana ◽  
Nadph Oxidase ◽  
Transcriptional Profiling ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Adaptive Responses ◽  
Oxidase Gene ◽  
Opposing Effects

Reactive oxygen species produced by NADPH oxidase and oxylipins derived from lipoxygenase activity can signal various stress conditions and have been implicated when plants are exposed to heavy metals. Transcriptional profiling of the 10 NADPH oxidase and 6 lipoxygenase genes was performed after exposure of Arabidopsis thaliana wild-type and NADPH oxidase mutants to 5 µM CdSO4 or 2 µM CuSO4 for 24 h. Under these short exposures to environmentally realistic concentrations of Cd or Cu, plants modulate signalling networks that regulate the onset of adaptive responses. Metal-specific NADPH oxidase genes were upregulated by Cd but downregulated by Cu, and metal-specific lipoxygenase gene expression was observed only after Cu exposure. Genes that are responsive to both metals were upregulated and may be responsive to general oxidative stress. For all metal-responsive genes except RBOHD, distinct responses were observed between leaves and roots, which may be due to different stress intensities and signalling mechanisms. Mutation of NADPH oxidase genes had opposing effects on gene expression after Cd or Cu exposure. Upregulation of LOX1 and LOX6 in the roots after exposure to Cd depended on NADPH oxidase gene expression, whereas LOX3 and LOX6 expression was induced more strongly in NADPH oxidase mutants after Cu exposure. Furthermore, NADPH oxidases regulated their own expression level and that of other members of the gene family when exposed to Cd or Cu. The results suggest interplay between reactive oxygen species and oxylipin signalling under Cd or Cu stress, and are useful as a basis for genetic studies to unravel metal-specific signalling mechanisms.

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