Ontology highlight
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PROVIDER: PRJNA1232373 | ENA |
REPOSITORIES: ENA
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Project description:Low iron (Fe) bioavailability can limit the biosynthesis of Fe-containing proteins, which are especially abundant in photosynthetic organisms, thus negatively affecting global primary productivity. Understanding cellular coping mechanisms under Fe limitation is therefore of great interest. We surveyed the temporal responses of Chlamydomonas (Chlamydomonas reinhardtii) cells transitioning from an Fe-rich to an Fe-free medium to document their short- and long-term adjustments. While slower growth, chlorosis and lower photosynthetic parameters are evident only after one or more days in Fe-free medium, the abundance of some transcripts, such as those for genes encoding transporters and enzymes involved in Fe assimilation, change within minutes, before changes in intracellular Fe content are noticeable, suggestive of a sensitive mechanism for sensing Fe. Promoter reporter constructs indicate a transcriptional component to this immediate primary response. With acetate provided as a source of reduced carbon, transcripts encoding respiratory components are maintained relative to transcripts encoding components of photosynthesis and tetrapyrrole biosynthesis, indicating metabolic prioritization of respiration over photosynthesis. In contrast to the loss of chlorophyll, carotenoid content is maintained under Fe limitation despite a decrease in the transcripts for carotenoid biosynthesis genes, indicating carotenoid stability. These changes occur more slowly, only after the intracellular Fe quota responds, indicating a phased response in Chlamydomonas, involving both primary and secondary responses during acclimation to poor Fe nutrition.
2024-04-04 | GSE263199 | GEO
Project description:Oxygenic photosynthesis contains multiple proteins that possess Fe2+ or Fe/S complexes as co-factors or prosthetic groups. Accordingly, its composition is heavily re-organized when iron becomes limiting as a nutrient factor, a situation that is frequently encountered in nature. However, the molecular mechanisms controlling the reorganization of the photosynthetic system upon iron deprivation have remained enigmatic. Here we show that the small regulatory RNA IsaR1 (Iron-stress activated RNA 1) plays a pivotal role in acclimation to low iron conditions. The transcription factor Fur cannot facilitate iron starvation dependent repression of it’s targets because it requires iron for DNA binding. We show that the Fur repressed sRNA IsaR1 fulfills this repressor function in iron homeostasis. The IsaR1 regulon consists of at least 15 direct targets, including Fe2+-containing proteins involved in photosynthetic electron transfer, the detoxification of anion radicals, citrate cycle, and in tetrapyrrole biogenesis. We demonstrate that IsaR1 is absolutely necessary to maintain physiological levels of Fe/S cluster biogenesis proteins during iron deprivation. Consequently, IsaR1 affects the acclimation of the photosynthetic apparatus to iron starvation at three levels: (i) directly, via posttranscriptional repression of gene expression and indirectly, (ii) via the suppression of Fe/S cluster co-factor and (iii) pigment biosynthesis. Homologs of IsaR1 are widely conserved throughout the cyanobacterial phylum. We conclude that IsaR1 is a riboregulator of central importance. These findings provide a new perspective for studies of the regulation of iron homeostasis in photosynthetic organisms.
2016-10-01 | GSE87496 | GEO
Project description:Interventions: Electro-acupuncture group:Electro-acupuncture;Sham electro-acupuncture group:Sham electro-acupuncture;Routine group:Routine therapy
Primary outcome(s): The time of first postoperative anal exhaust
Study Design: Parallel
| 41280 | ecrin-mdr-crc
Project description:Abstract Background: Gene transfer by electroporation (electro gene transfer) to muscle results in high level long term transgenic expression, showing great promise for treatment of e.g. protein deficiency syndromes. However little is known about the effects of electro gene transfer on muscle fibres. We have therefore investigated transcriptional changes through gene expression profile analyses, as well as morphological changes evaluated by histological analysis. Electro gene transfer was obtained using a combination of a short high voltage pulse (HV, 1000 V/cm, 100 @s) followed by a long low voltage pulse (LV, 100 V/cm, 400 ms); a pulse combination optimised for efficient and safe gene transfer. Muscles were transfected with green fluorescent protein (GFP) and excised at 4 hours, 48 hours or 3 weeks after treatment. Results: Differentially expressed genes were investigated by microarray analysis, and descriptive statistics were performed to evaluate the effects of 1) electroporation, 2) DNA injection, and 3) time after treatment. The biological significance of the results was assessed by gene annotation and supervised cluster analysis. Generally, electroporation caused down-regulation of structural proteins e.g. sarcospan and catalytic en-zymes such as phosphoenolpuryvate carboxykinase. Injection of DNA induced down-regulation of intracellular transport proteins e.g. sentrin. The effects on muscle fibres were transient as the expression profiles 3 weeks after treatment were closely related with the control muscles. Most interestingly, no changes in the expression of proteins involved in inflammatory responses or muscle regeneration was detected, indicating limited muscle damage and regeneration. Histological analysis revealed structural changes with loss of cell integrity and striation pattern in some fibres after DNA+HV+LV treatment, while electroporation alone caused minor loss of striation pattern but preservation of cell integrity. Conclusion: The small and transient changes found in the gene expression profiles are of great importance, as this demonstrates that electro gene transfer is safe with minor effects on the muscle host cells. These findings are essential for introducing the electro gene transfer to muscle for clinical use. Indeed the HV+LV pulse combination used have been optimised to ensure highly efficient and safe electro gene transfer. Keywords: Electro gene transfer, microarray, affymetrix, gene therapy, skeletal muscle, mouse, time course
2007-07-05 | GSE6686 | GEO
Project description:microbes in sediment and sediment amended with Pd/Fe Metagenomic assembly
| PRJNA554467 | ENA
Project description:We performed small RNA-seq (sRNA-seq) study of Arabidopsis shoots under iron-sufficient (+Fe), iron deficient (-Fe) and iron resupply (Fe resupply) conditions to investigate and identify sRNAs whose expression is regulated by iron deficiency.
2022-09-15 | GSE209594 | GEO
Project description:We compared the URI binding to the chromosome in roots between +Fe and -Fe conditions.
2019-12-06 | GSE137645 | GEO
Project description:In this study we developed MPE-seq, a method for the genome-wide characterization of chromatin that involves the digestion of nuclei with methidiumpropyl-EDTA-Fe(II) [MPE-Fe(II)] followed by massively parallel sequencing. Like micrococcal nuclease (MNase), MPE-Fe(II) preferentially cleaves the linker DNA between nucleosomes. We also performed MNase-seq as a comparison. We further performed ChIP-seq using chromatin samples obtained by MPE-Fe(II) or MNase digestion of nuclei.
2015-06-16 | GSE69098 | GEO
Project description:Inflammation, caused by accumulation of inflammatory cytokines from immunocytes, is prevalent in a variety of diseases. Electro-stimulation emerges as a promising candidate for inflammatory inhibition. Although electroacupuncture is free from surgical injury, it faces the challenges of imprecise pathways/current spikes, and insufficiently defined mechanisms, while non-optimal pathway or spike would require high current amplitude, which makes electro-stimulation usually accompanied by damage and complications. Here, we propose a neuromorphic electro-stimulation based on atomically thin semiconductor floating-gate memory interdigital circuit. Direct stimulation is achieved by wrapping sympathetic chain with flexible electrodes and floating-gate memory are programmable to fire bionic spikes, thus minimizing nerve damage. A substantial decrease (73.5%) in inflammatory cytokine IL-6 occurred, which also enabled better efficacy than commercial stimulator at record-low currents with damage-free to sympathetic neurons. Additionally, using transgenic mice, the anti-inflammation effect is determined by β2 adrenergic signaling from myeloid cell lineage (monocytes/macrophages and granulocytes).
2024-01-20 | GSE253300 | GEO
Project description:The Arabidopsis thaliana Myb transcription factor, FE, acts as a key regulator of phase transition. In order to identify potential target genes of FE protein, we performed microarray experiments. Using fe-1 and transgenic plants overexpressing GR-tagged FE (35S::FE-GR), we compared transcriptional profiling of WT (L.er) vs fe-1 and Dex-treated 35S::FE-GR vs Mock-treated 35S::FE-GR. Transcriptional profiling of A. thaliana comparing WT (L.er) with the fe-1 mutant
2017-01-01 | GSE42862 | GEO