Search results for "Exon"
showing 10 items of 437 documents
Neuroglobin, cytoglobin, and a novel, eye-specific globin from chicken
2004
Neuroglobin and cytoglobin are two recently discovered respiratory proteins of vertebrates. Here we report the first identification and expression analyses of these proteins in bird species. Neuroglobin from the domestic chicken Gallus gallus differs in approximately 30% from the mammalian proteins, but its genome structure shows the conservation of the B12.2, E11.0, and G7.0 intron positions. The chicken cytoglobin protein is shorter than the mammalian orthologs, from which it differs overall by approximately 25%, due to the absence of the C-terminal exon in the gene. Comparison of chicken and mammalian gene order shows that neuroglobin and cytoglobin are located on conserved syntenic chro…
Duplicated cytoglobin genes in teleost fishes
2005
Cytoglobin is a recently discovered myoglobin-related O2-binding protein of vertebrates with uncertain function. It occurs as single-copy gene in mammals. Here, we demonstrate the presence of two paralogous cytoglobin genes (Cygb-1 and Cygb-2) in the teleost fishes Danio rerio, Oryzias latipes, Tetraodon nigroviridis, and Takifugu rubripes. The globin-typical introns at positions B12.2 and G7.0 are conserved in both genes, whereas the C-terminal exon found in mammalian cytoglobin is absent in the fish genes. Phylogenetic analyses show that the two cytoglobin genes diverged early in teleost evolution. This is confirmed by gene synteny analyses, which suggest a large-scale duplication event. …
Determination of steady-state levels of oxidative DNA base modifications in mammalian cells by means of repair endonucleases
1997
The alkaline elution technique in combination with various repair endonucleases (Fpg protein, endonuclease III, exonuclease III, T4 endonuclease V) was used to quantify steady-state (background) levels of oxidative base modifications in various types of mammalian cells. In human lymphocytes the number of base modifications sensitive to Fpg protein, which include 8-hydroxyguanine, was 0.25 +/- 0.05 per 10(6) base pairs. Even lower levels (0.07 +/- 0.02 per 10(6) bp) were observed in HeLa cells. The numbers of sites sensitive to the other repair endonucleases were below the detection limit (0.05 per 10(6) bp). In a direct comparison, the background level of Fpg-sensitive modifications determi…
RNA-controlled nucleocytoplasmic shuttling of mRNA decay factors regulates mRNA synthesis and initiates a novel mRNA decay pathway
2021
AbstractmRNA level is controlled by factors that mediate both mRNA synthesis and decay, including the exonuclease Xrn1 - a major mRNA synthesis and decay factor. Here we show that nucleocytoplasmic shuttling of Xrn1 and of some of its associated mRNA decay factors plays a key role in determining both mRNA synthesis and decay. Shuttling is regulated by RNA-controlled binding of the karyopherin Kap120 to two nuclear localization sequences (NLSs) in Xrn1. The decaying RNA binds and masks NLS1, establishing a link between mRNA decay and Xrn1 shuttling. Mutations in the two NLSs, which prevent Xrn1 import, compromise transcription and, unexpectedly, also the cytoplasmic decay of ∼50% of the cell…
Aceruloplasminemia: a case report
2008
Hereditary aceruloplasminemia is a rare autosomal recessive disease, firstly identified by Miyajima et al. in Japan in 1987 [1]. The disease is caused by the absence of an a2glycoprotein, the ceruloplasmin (Cp), a copper-containing ferroxidase, mainly synthesized in hepatocytes and widely expressed, including the central nervous system, which catalyses the oxidation of ferrous to ferric iron, a change required for release of iron to plasma transferrin [2]. It is hypothesized that in reticuloendothelial (RE) cells and hepatocytes Cp cooperates to export iron with the iron exporter protein ferroportin 1 (FPN1) [3]. As a consequence, Cp deficiency results in iron deposition in the liver, pancr…
Absence of mutations in the WT1 gene in patients with XY gonadal dysgenesis
1995
The WT1 gene is normally expressed during gonadal development and specific mutations in heterozygous form cause Drash syndrome, characterized by male pseudohermaphroditism and gonadal dysgenesis, renal failure and a predisposition for Wilms' tumour. These observations prompted us to test whether WT1 mutations are involved in isolated gonadal dysgenesis, being the most severe form of disturbance in gonadal differentiation. We studied 27 cases of 46,XY females with gonadal dysgenesis who had previously been screened for and found not to carry SRY gene mutations. We performed mutational screening of the WT1 gene with denaturing gradient gel electrophoresis. In one of these patients, a heterozy…
Diagnosis of exon 12‐positive polycythemia vera rescued by NGS
2020
Abstract A JAK2V617F‐negative polycythemia associated with low serum epo needs to be tested for an exon 12 JAK2 mutation. When negative, due to potential serious complications in PV, a next generation sequencing is necessary to rule out false negative results.
Exercise-induced euphoria and anxiolysis do not depend on endogenous opioids in humans
2021
Abstract A runner's high describes a sense of well-being during endurance exercise characterized by euphoria and anxiolysis. It has been a widespread belief that the release of endogenous opioids, such as endorphins, underlie a runner's high. However, exercise leads to the release of two classes of rewarding molecules, endocannabinoids (eCBs) and opioids. In mice, we have shown that core features of a runner's high depend on cannabinoid receptors but not opioid receptors. In the present study, we aimed to corroborate in humans that endorphins do not play a significant role in the underlying mechanism of a runner's high. Thus, we investigated whether the development of two core features of a…
Expression of Wild-Type and Variant Estrogen Receptor Alpha in Liver Carcinogenesis and Tumor Progression.
2011
Although estrogen receptors (ERs) are expressed in human hepatocellular carcinoma (HCC), several clinical trials have failed to demonstrate the efficacy of antiestrogen treatment in HCC patients. Recently, the identification of several ER splicing variants has enlightened the complex nature of estrogen signaling in peripheral tissues; this may help understanding estrogen role in either nontumoral or malignant nonclassical target organs, including liver. In this work we have investigated mRNA expression of wild-type and splice variants of ERα in nontumoral, cirrhotic, and malignant human liver, as well as in HCC cell lines, using an exon-specific reverse transcription polymerase chain reacti…
Congenital secondary hypothyroidism caused by exon skipping due to a homozygous donor splice site mutation in the TSHbeta-subunit gene.
2002
Isolated TSH deficiency as a cause for congenital hypothyroidism is relatively uncommon. Even more rare is the identification of mutations in the TSHβ gene, only four of which have been identified. We here report a 4-month-old girl with isolated TSH deficiency born to consanguineous parents. Sequencing of the TSHβ-subunit gene revealed a homozygous G to A transition at position +5 of the donor splice site of intron 2. TSHβ gene transcript could not be obtained from fibroblasts or white blood cells by illegitimate amplification. Thus, to investigate further the mechanism leading to TSH deficiency in this patient, we used an in vitro exon-trapping system. The mutation at position +5 of the do…