Search results for " Gene Expression"
showing 10 items of 695 documents
Increased AICD generation does not result in increased nuclear translocation or activation of target gene transcription.
2008
A sequence of amyloid precursor protein (APP) cleavages culminates in the sequential release of the APP intracellular domain (AICD) and the amyloid beta peptide (Abeta) and/or p3 fragment. One of the environmental factors favouring the accumulation of AICD appears to be a rise in intracellular pH. Here we further identified the metabolism and subcellular localization of artificially expressed constructs under such conditions. We also co-examined the mechanistic lead up to the AICD accumulation and explored possible significances for its increased expression. We found that most of the AICD generated under pH neutralized conditions is likely cleaved from C83. While the AICD surplus was unable…
The POT1 gene for yeast peroxisomal thiolase is subject to three different mechanisms of regulation
1992
The Saccharomyces cerevisiae POT1 gene is, as are other yeast peroxisomal protein genes, inducible by fatty acids and repressible by glucose. We have now found that it is also induced during the stationary phase of the culture. To investigate these three regulatory circuits, we have studied the mRNA levels of regulatory mutants as well as the changes in chromatin structure upon gene activation. We conclude that the regulation of transcriptional activity in glucose repression, oleate induction, and stationary phase induction follow different molecular mechanisms. We suggest that this multiplicity of regulatory mechanisms may represent a general rule for the yeast peroxisomal protein genes.
Cadmium as a transcriptional modulator in human cells
2010
Cadmium (Cd) is an underground mineral widely used in the steel industry, in plastics, and as a component of batteries. It is an industrial and environmental pollutant released as an air contaminant from fertilizers and, more prominently, in the form of wastewater. Food, drinking water, and, mainly, inhalation of smoke from cigarettes are sources of daily exposure of humans to the heavy metal. Although Cd has no known useful function for humans as well as other organisms, it appears to evoke in cells a number of responses that involve not only death signaling but also protective reactions against the toxicity. This finding prompted a number of experimental studies aimed to elucidate the cel…
A differential role of CREB phosphorylation in cAMP-inducible gene expression in the rat pineal
2000
In the rat pineal gland cAMP mediates nocturnal induction of the enzyme arylalkylamine N-acetyltransferase (AA-NAT) as well as of transcription factors such as inducible cAMP early repressor (ICER), Fos-related antigen-2 (Fra-2) and JunB. Cyclic AMP stimulates the phosphorylation of the DNA binding protein cAMP response element binding protein (CREB). While cAMP-induced CREB phosphorylation appears to be a prerequisite for AA-NAT and ICER gene expression, it is not known whether CREB phosphorylation accounts for the full cAMP response of the two genes. Furthermore, the significance of CREB phosphorylation in cAMP-activated Fra-2 and JunB transcription is unknown. In the present in vitro stu…
PCF11 links alternative polyadenylation to formation and spontaneous regression of neuroblastoma
2018
AbstractDiversification at the transcriptome 3’end is an important and evolutionarily conserved layer of gene regulation associated with differentiation and dedifferentiation processes. However the underlying mechanisms and functional consequences are poorly defined. Here, we identify extensive transcriptome-3’end-alterations in neuroblastoma, a tumour entity with a paucity of recurrent somatic mutations and an unusually high frequency of spontaneous regression. Utilising extensive RNAi-screening we reveal the landscape and drivers of transcriptome-3’end-diversification, discovering PCF11 as critical regulator, directing alternative polyadenylation (APA) of hundreds of transcripts including…
Expression of a reporter gene is reduced by a ribozyme in transgenic plants
1994
A chimeric gene encoding a ribozyme under the control of the cauliflower mosaic virus (CaMV) 35S promoter was introduced into transgenic tobacco plants. In vivo activity of this ribozyme, which was designed to cleave npt mRNA, was previously demonstrated by transient expression assays in plant protoplasts. The ribozyme gene was transferred into transgenic tobacco plants expressing an rbcS-npt chimeric gene as an indicator. Five double transformants out of sixteen exhibited a reduction in the amount of active NPT enzyme. To measure the amount of ribozyme produced, in the absence of its target, the ribozyme and target genes were separated by genetic segregation. The steady-state concentration…
Homeostasis in the Central Dogma of molecular biology: the importance of mRNA instability
2019
Cell survival requires the control of biomolecule concentration, i.e. biomolecules should approach homeostasis. With information-carrying macromolecules, the particular concentration variation ranges depend on each type: DNA is not buffered, but mRNA and protein concentrations are homeostatically controlled, which leads to the ribostasis and proteostasis concepts. In recent years, we have studied the particular features of mRNA ribostasis and proteostasis in the model organism S. cerevisiae. Here we extend this study by comparing published data from three other model organisms: E. coli, S. pombe and cultured human cells. We describe how mRNA ribostasis is less strict than proteostasis. A co…
piRNAclusterDB 2.0: update and expansion of the piRNA cluster database.
2021
Abstract PIWI-interacting RNAs (piRNAs) and their partnering PIWI proteins defend the animal germline against transposable elements and play a crucial role in fertility. Numerous studies in the past have uncovered many additional functions of the piRNA pathway, including gene regulation, anti-viral defense, and somatic transposon repression. Further, comparative analyses across phylogenetic groups showed that the PIWI/piRNA system evolves rapidly and exhibits great evolutionary plasticity. However, the presence of so-called piRNA clusters as the major source of piRNAs is common to nearly all metazoan species. These genomic piRNA-producing loci are highly divergent across taxa and critically…
A FOX Binding Site is Necessary for the Activation of Pl-Tuba1a Gene in the neurogenic domains
2016
All echinoderm larvae possess a nervous system consisting of a ciliary band and associated sensory ganglia (apical, oral and lateral ganglia) that controls swimming and feeding. Neurons of the larval nervous system first appear as neuroblasts in the thickened ectoderm of the animal plate (anterior neuroectoderm, ANE) at the late blastula – early gastrula stage and then also in the ciliary band. The neural differentiation process of sea urchin embryos has been analysed and the Gene Regulatory Network involved in the differentiation processes is extensively studied. We have previously isolated an alpha tubulin family member of the sea urchin Paracentrotus lividus (Pl-Tuba1a, formerly known as…
MMP-10/stromelysin-2 promotes invasion of head and neck cancer.
2011
BackgroundPeriostin, IFN-induced transmembrane protein 1 (IFITM1) and Wingless-type MMTV integration site family, member 5B (Wnt-5b) were previously identified as the invasion promoted genes of head and neck squamous cell carcinoma (HNSCC) by comparing the gene expression profiles between parent and a highly invasive clone. We have previously reported that Periostin and IFITM1 promoted the invasion of HNSCC cells. Here we demonstrated that Wnt-5b overexpression promoted the invasion of HNSCC cells. Moreover, stromelysin-2 (matrix metalloproteinase-10; MMP-10) was identified as a common up-regulated gene among Periostin, IFITM1 and Wnt-5b overexpressing HNSCC cells by using microarray data s…