Search results for " Regulation"
showing 10 items of 3187 documents
Interspecies comparison of neuroglobin, cytoglobin and myoglobin: Sequence evolution and candidate regulatory elements
2003
Neuroglobin and cytoglobin are two novel members of the vertebrate globin family. Their physiological role is poorly understood, although both proteins bind oxygen reversibly and may be involved in cellular oxygen homeostasis. Here we investigate the selective constraints on coding and non-coding sequences of the neuroglobin and cytoglobin genes in human, mouse, rat and fish. Neuroglobin and cytoglobin are highly conserved, displaying very low levels of non-synonymous nucleotide substitutions. An oxygen supply function predicts distinct modes of gene regulation, involving hypoxia-responsive transcription factors. To detect conserved candidate regulatory elements, we compared the neuroglobin…
Molecular characterization of the zerknüllt region of the Antennapedia complex of D. subobscura.
1995
We have characterized at the molecular level the zerknullt (zen) region of the Drosophila subobscura Antennapedia complex. The sequence comparison between D. subobscura and D. melanogaster shows an irregular distribution of the conserved and diverged regions, with the homeobox and a putative activating domain completely conserved. Comparisons of the promoter sequence and pattern of expression of the gene during development suggest that the regulation of zen has been conserved during evolution. The conservation of zen expression in a subpopulation of the polar cells indicates the existence of an important role in such cells. We describe a transitory segmented pattern of expression of zen in …
Pythium terrestris, a new species isolated from France, its ITS region, taxonomy and its comparison with related species
2002
Pythium terrestris (F-78) was isolated from soil samples taken in Lille in northern France. Its morphology resembles that of Pythium rostratum, and Pythium longandrum, a recently described species. However the antheridial and sporangial characteristics of this new species are unique. The fungus does not sporulate, the sporangium germinates directly into mycelium through germ tubes. The oogonia of P. terrestris are normally provided with hypogynous and monoclinous antheridia, at times the monoclinous antheridial branches wrap around the oogonia forming a complicated knot. Morphological features of this new species, together with the sequences of the internal transcribed spacer (ITS) region o…
Effects of cadmium exposure on sea urchin development assessed by SSH and RT-qPCR: metallothionein genes and their differential induction
2012
In order to study the defense strategies activated by Paracentrotus lividus embryos in response to sub-lethal doses of CdCl2, we compared the induced transcripts to that of control embryos by suppression subtractive hybridization technique. We isolated five metallothionein (MT) cDNAs and other genes related to detoxification, to signaling pathway components, to oxidative, reductive and conjugative biotransformation, to RNA maturation and protein synthesis. RT-qPCR analysis revealed that two of the five P. lividus MT (PlMT7 and PlMT8) genes appeared to be constitutively expressed and upregulated following cadmium treatment, whereas the other three genes (PlMT4, PlMT5, PlMT6) are specifically…
A Na+-coupled C4-dicarboxylate transporter (Asuc_0304) and aerobic growth of Actinobacillus succinogenes on C4-dicarboxylates
2014
Actinobacillus succinogenes, which is known to produce large amounts of succinate during fermentation of hexoses, was able to grow on C4-dicarboxylates such as fumarate under aerobic and anaerobic conditions. Anaerobic growth on fumarate was stimulated by glycerol and the major product was succinate, indicating the involvement of fumarate respiration similar to succinate production from glucose. The aerobic growth on C4-dicarboxylates and the transport proteins involved were studied. Fumarate was oxidized to acetate. The genome of A. succinogenes encodes six proteins with similarity to secondary C4-dicarboxylate transporters, including transporters of the Dcu (C4-dicarboxylate uptake), Dcu…
Rational design of allosteric modulators of the aromatase enzyme: An unprecedented therapeutic strategy to fight breast cancer.
2019
Estrogens play a key role in cellular proliferation of estrogen-receptor-positive (ER+) breast cancers (BCs). Suppression of estrogen production by competitive inhibitors of the enzyme aromatase (AIs) is currently one of the most effective therapies against ER + BC. Yet, the development of acquired resistance, after prolonged treatments with AIs, represents a clinical major concern. Serendipitous findings indicate that aromatase may be non-competitively inhibited by clinically employed drugs and/or industrial chemicals. Here, by performing in silico screening on two putative allosteric sites, molecular dynamics and free energy simulations, supported by enzymatic and cell-based assays, we id…
Minireview: Recent progress in hemocyanin research
2011
This review summarizes recent highlights of our joint work on the structure, evolution, and function of a family of highly complex proteins, the hemocyanins. They are blue-pigmented oxygen carriers, occurring freely dissolved in the hemolymph of many arthropods and molluscs. They are copper type-3 proteins and bind one dioxygen molecule between two copper atoms in a side-on coordination. They possess between 6 and 160 oxygen-binding sites, and some of them display the highest molecular cooperativity observed in nature. The functional properties of hemocyanins can be convincingly described by either the Monod-Wyman-Changeux (MWC) model or its hierarchical extension, the Nested MWC model; the…
Immunohistochemical analysis of KCNQ2 potassium channels in adult and developing mouse brain
2005
The syndrome of benign familial neonatal convulsions (BFNC) is characterized by seizures starting within the first days of life and disappearing within weeks to months. BFNC is caused by loss-of-function mutations in the potassium channels KCNQ2 and KCNQ3 which can well explain the resulting neuronal hyperexcitability. However, it is not understood why seizures predominantly occur in the neonatal period. A potential explanation might be a change in the expression pattern of these channels during development. We therefore performed an immunohistochemical analysis of mouse brain slices at different stages of postnatal development using an antibody recognizing the C-terminus of the KCNQ2 chann…
Calcitonin gene related peptide gene expression in collagen-induced arthritis
1995
On a evalue par hybridation in situ semi-quantitative les variations de l'expression genique du peptide lie au gene de la calcitonine (CGRP) dans les motoneurones spinaux et dans les ganglions des racines dorsales (GRD) de rats chez lesquels l'arthrite a ete induite par l'administration de collagene II (AIC). On a examine les effets d'un traitement systemique avec le corticosteroide budesonide sur l'expression basale du CGRP ainsi que sur ses variations dans des conditions d'inflammation. Dans les GRD, l'AIC a induit une augmentation significative des taux d'ARNm du CGRP. Le budesonide a reduit les taux d'ARNm du CGRP constitutif de ces GRD comparativement a ceux des rats temoins non traite…
Unravelling the DNA sequences carried by Streptomyces coelicolor membrane vesicles
2022
AbstractMembrane vesicles (MVs) are spherical particles with nanoscale dimensions and characterized by the presence of diverse cargos, such as nucleic acids, proteins, lipids, and cellular metabolites. Many examples of (micro)organisms producing MVs are reported in literature. Among them, bacterial MVs are of particular interest because they are now considered as the fourth mechanism of horizontal gene transfer. Streptomyces bacteria are well-known for their ecological roles and ability to synthesize bioactive compounds, with Streptomyces coelicolor being the model organism. It was previously demonstrated that it can produce distinct populations of MVs characterized by different protein and…