Search results for "Transcription"
showing 10 items of 2278 documents
Genomics of mRNA turnover
2007
Most studies on eukaryotic gene regulation have focused on mature mRNA levels. Nevertheless, the steady-state mRNA level is the result of two opposing biological processes: transcription and degradation, both of which can be important points to regulate gene expression. It is now possible to determine the transcription and degradation rates (TR and DR), as well as the mRNA amount, for each gene using DNA chip technologies. In this way, each individual contribution to gene expression can be analysed. This review will deal with the techniques used for the genomic evaluation of TR and DR developed for the yeast Saccharomyces cerevisiae. They will be described in detail and their potential draw…
Differential expression of collagen types I, III, and IV by fat-storing (Ito) cells in vitro
1992
It has been observed that Ito cells in vitro undergo phenotypical changes ("activation") similar to those noted in vivo during the development of liver fibrosis. Because conflicting data have been published on the amount and different types of collagens synthesized by Ito cells in vitro, collagen biosynthesis was studied at different "activation" stages on both the protein and RNA levels. Immunoprecipitation of endogenously labeled collagen showed that freshly isolated ("resting") Ito cells synthesize mainly collagen type IV. Collagen type I was hardly detectable in the earlier stage of primary culture, but it clearly increased starting 5 days after isolation. Compared with the basal rates …
The main cold shock protein of Listeria monocytogenes belongs to the family of ferritin-like proteins
2000
The transfer of the food-borne pathogen Listeria monocytogenes from 30 to 5 degrees C was characterized by the sharp induction of a low molecular mass protein. This major cold shock protein has an isoelectric point at pH 5.1 and a molecular mass of about 18 kDa, as observed on two-dimensional gel electrophoresis (2-DE) pattern. Its N-terminal sequence, obtained from the 2-DE spot, shared a complete sequence identity with a Listeria innocua non-heme iron-binding ferritin. The purification of these ferritin-like proteins (Flp) revealed a native molecular mass of about 100-110 kDa which indicates a polypeptide composed of six 18 kDa-subunits. Northern analysis indicated the presence of a 0.8-k…
A major cysteine proteinase, EPB, in germinating barley seeds: structure of two intronless genes and regulation of expression
1996
The barley cysteine proteinase B (EPB) is the main protease responsible for the degradation of endosperm storage proteins providing nitrogenous nutrients to support the growth of young seedlings. The expression of this enzyme is induced in the germinating seeds by the phytohormone, gibberellin, and suppressed by another phytohormone, abscisic acid. In situ hybridization experiments indicate that EPB is expressed in the scutellar epithelium within 24 h of seed germination, but the aleurone tissue surrounding the starchy endosperm eventually becomes the main tissue expressing this enzyme. The EPB gene family of barley consists of two very similar genes, EPB1 and EPB2, both of which have been …
Nuclear factors binding to the extensin promoter exhibit differential activity in carrot protoplasts and cells
1992
The expression of the cell wall protein extensin, a hydroxyproline-rich glycoprotein, is induced by several different stimuli, including wounding. The process of protoplast preparation mimics the wounding effect and results in the induction of extensin. Using transient expression in protoplasts we analyzed several deletions of the extensin promoter. We identified an important transcriptional regulatory element located between the two TATA boxes that characterize the extensin promoter. Other regulatory elements, located further upstream between -719 to -658, are necessary for maximum level of expression. Employing electrophoretic mobility shift assays and methylation interference experiments…
Destabilized green fluorescent protein detects rapid removal of transcription blocks after genotoxic exposure
2007
High stabilities of reporter proteins and their messenger RNAs (mRNAs) interfere with the detection of rapid transient changes in gene expression, such as transcriptional blocks posed by genotoxic DNA lesions. We have modified a green fluorescent protein (GFP) gene within the episomal pMARS vector by addition of a fragment encoding for mouse ornithine decarboxylase (ODC) proline-glutamate-serine-threonine-rich (PEST) sequence in order to target the protein to the proteasomes and achieved an unprecedentedly fast GFP turnover in permanently transfected human cells. As early as 1 h after inhibition of protein synthesis by cycloheximide, the number of fluorescent cells decreased more than 5-fo…
Beclomethasone dipropionate and formoterol reduce oxidative/nitrosative stress generated by cigarette smoke extracts and IL-17A in human bronchial ep…
2013
Interleukin-17A (IL-17A), cigarette smoke and oxidative/nitrosative stress are involved in inflammatory airway diseases, and the mechanisms behind these processes are still poorly understood. We investigated whether recombinant human IL-17A (rhIL-17A), in combination with cigarette smoke extracts (CSE), increases the levels of inducibile nitric oxide synthase (iNOS), reactive oxygen species, nitrotyrosine (NT) and the activation of signal transducer and activator of transcription 1 (STAT-1) in normal human bronchial epithelial cells (16HBE). The effect of beclomethasone dipropionate (BDP), formoterol and their combination was also evaluated. We demonstrated that rhIL-17A or CSE alone increa…
Energy requirement and kinetics of transport of poly(A)-free histone mRNA compared to poly(A)-rich mRNA from isolated L-cell nuclei.
1989
ATP-promoted efflux of poly(A)-rich RNA from isolated nuclei of prelabeled mouse lymphoma L5178y cells has an activation energy of 51.5 kJ/mol, similar to that found for the nuclear envelope nucleoside triphosphatase (48.1 kJ/mol) assumed to be involved in mediating nucleocytoplasmic transport of at least some RNA. Here we show that efflux of two specific poly(A)-rich mRNAs (actin and beta-tubulin) from isolated L-cell nuclei is almost totally dependent on the presence of ATP, while efflux of poly(A)-free histone mRNA (H4, H2B, and H1) also occurs to a marked extent in the absence of this nucleotide. Measurements of temperature dependence of transport rate revealed an activation energy of 5…
Transcriptional Activity and Nuclear Localization of Cabut, the Drosophila Ortholog of Vertebrate TGF-β-Inducible Early-Response Gene (TIEG) Proteins
2011
Background Cabut (Cbt) is a C2H2-class zinc finger transcription factor involved in embryonic dorsal closure, epithelial regeneration and other developmental processes in Drosophila melanogaster. Cbt orthologs have been identified in other Drosophila species and insects as well as in vertebrates. Indeed, Cbt is the Drosophila ortholog of the group of vertebrate proteins encoded by the TGF-s-inducible early-response genes (TIEGs), which belong to Sp1-like/Kruppel-like family of transcription factors. Several functional domains involved in transcriptional control and subcellular localization have been identified in the vertebrate TIEGs. However, little is known of whether these domains and fu…
Transcriptional analysis of the nitrile‐degrading operon from Rhodococcus sp. ACV2 and high level production of recombinant amidase with an Escherich…
1999
Northern blotting analysis with RNA probes derived from amidase and nitrile hydratase genes from Rhodococcus sp. ACV2 revealed that both genes are part of the same operon. RNase protection mapping and sequence analysis indicated that the operon is probably under the control of a sigma 70-like promoter located upstream from the amidase gene. Plasmids were constructed with the cloned genes under tac and lac promoter control. Expression of amdA was demonstrated in Escherichia coli. In another construction, the amdA gene was inserted under the control of the bacteriophage T7 promoter. Large amounts of recombinant amidase (at least 20% of total proteins) in a soluble and active form were obtaine…