Search results for "Untranslated region"

Functional Significance of Microsatellite Markers

2014

The review summarizes literature data on the positive results of association studies between the length of microsatellite repeats and predisposition to pathologies. Actually, the data can be classified according to the localization of the microsatellite: in the gene promoter, in the part of exon 1 coding the signal sequence, in gene introns, in the coding areas of genes, and in 3'-untranslated regions. The functional significance of microsatellite length changes can be evaluated in many cases. The authors came up to the conclusion that further studies on microsatellite associations with diseases remain prospective as they reflect changes in the gene functional activity.

The human fascin gene promoter is highly active in mature dendritic cells due to a stage-specific enhancer.

2003

Abstract Dendritic cells (DC), regarded as the most efficient APCs of the immune system, are capable of activating naive T cells. Thus, DC are primary targets in immunotherapy. However, little is known about gene regulation in DC, and for efficient transcriptional targeting of human DC, a suitable promoter is still missing. Recently, we successfully used the promoter of the murine actin-bundling protein fascin to transcriptionally target DC by DNA vaccination in mice. In this study, we report on isolation of the human fascin promoter and characterization of its regulatory elements. The actively expressed gene was distinguished from a conserved inactive genomic locus and a continuous region …

Analysis of the Single-Nucleotide Polymorphism in the 5′UTR and Part of Intron I of the Sheep MSTN Gene

2011

The myostatin (MSTN) gene region encompassing the 5′UTR and part of intron I was sequenced in animals of two herds of Latvian Darkhead sheep to extend data on the ovine MSTN gene polymorphism and to provide information useful for local breed conservation. Two and four polymorphic loci were revealed in the 5′UTR and intron I. Four and five local haplotypes were constructed, respectively. The genotyping data obtained and that previously reported for the same genomic region were combined in one dataset for the haplotype analysis. Recombination events were detected between loci (c.−40, c.−37) in the 5′UTR and (c.373+18, c.373+101) and (c.373+101, c.373+241) in intron I. Single-nucleotide polymo…

Specific roles of 5′ RNA secondary structures in stabilizing transcripts in chloroplasts

2005

RNA secondary structures, e.g. stem-loops that are often found at the 5' and 3' ends of mRNAs, are in many cases known to be crucial for transcript stability but their role in prolonging the lifetime of transcripts remains elusive. In this study we show for an essential RNA-stabilizing stem-loop at the 5' end of rbcL gene transcripts in Chlamydomonas that it neither prevents ribonucleases from binding to the RNA nor impedes their movement along the RNA strand. The stem-loop has a formative function in that it mediates folding of a short sequence around its base into a specific RNA conformation, consisting of a helical and single-stranded region, i.e. the real structure required for longevit…

Structures of two molluscan hemocyanin genes: significance for gene evolution.

2001

We present here the description of genes coding for molluscan hemocyanins. Two distantly related mollusks, Haliotis tuberculata and Octopus dofleini , were studied. The typical architecture of a molluscan hemocyanin subunit, which is a string of seven or eight globular functional units (FUs, designated a to h, about 50 kDa each), is reflected by the gene organization: a series of eight structurally related coding regions in Haliotis , corresponding to FU-a to FU-h, with seven highly variable linker introns of 174 to 3,198 bp length (all in phase 1). In Octopus seven coding regions (FU-a to FU-g) are found, separated by phase 1 introns varying in length from 100 bp to 910 bp. Both genes exh…

2014

Genetic factors underlie a substantial proportion of individual differences in cognitive functions in humans, including processes related to episodic and working memory. While genetic association studies have proposed several candidate "memory genes", these currently explain only a minor fraction of the phenotypic variance. Here, we performed genome-wide screening on 13 episodic and working memory phenotypes in 1,318 participants of the Berlin Aging Study II aged 60 years or older. The analyses highlight a number of novel single nucleotide polymorphisms (SNPs) associated with memory performance, including one located in a putative regulatory region of microRNA (miRNA) hsa-mir-138-5p (rs9882…

Eukaryotic mRNA decay: methodologies, pathways, and links to other stages of gene expression.

2012

mRNA concentration depends on the balance between transcription and degradation rates. On both sides of the equilibrium, synthesis and degradation show, however, interesting differences that have conditioned the evolution of gene regulatory mechanisms. Here, we discuss recent genome-wide methods for determining mRNA half-lives in eukaryotes. We also review pre- and posttranscriptional regulons that coordinate the fate of functionally related mRNAs by using protein- or RNA-based trans factors. Some of these factors can regulate both transcription and decay rates, thereby maintaining proper mRNA homeostasis during eukaryotic cell life.

Study of β-defensin polymorphisms in Valle del Belice dairy sheep

2009

The aim of this work was to sequence the exons of β-defensin 1 and 2 genes (SBD1 and SBD2) in Valle del Belice dairy sheep in order to identify polymorphisms. The study was conducted on 60 samples from three flocks. Six SNPs were identified: two in SBD1 and four in SBD2. Both genes consist of two exons and one intron. In SBD1 gene, SNPs were found only in the exon 2, whereas in SBD2, SNPs were detected in both exons. In both genes, SNPs were located in the coding regions and in the 3'-UTR. The SNP in SBD2 located at position 1659 determined a change in the protein sequence. Further studies will be necessary to investigate if the amino acid change modifies the biological function of the…

Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair

2015

Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed …

Sequences in the 5′ Nontranslated Region of Hepatitis C Virus Required for RNA Replication

2001

ABSTRACT Sequences in the 5′ and 3′ termini of plus-strand RNA viruses harbor cis -acting elements important for efficient translation and replication. In case of the hepatitis C virus (HCV), a plus-strand RNA virus of the family Flaviviridae , a 341-nucleotide-long nontranslated region (NTR) is located at the 5′ end of the genome. This sequence contains an internal ribosome entry site (IRES) that is located downstream of an about 40-nucleotide-long sequence of unknown function. By using our recently developed HCV replicon system, we mapped and characterized the sequences in the 5′ NTR required for RNA replication. We show that deletions introduced into the 5′ terminal 40 nucleotides abolis…