PubMed HealthSearch

SEARCH · PubMed Health

Results for “U1snRNA”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

3 recordsLinked to original sources

Characterization and expression of U1snRNA genes from potato.

U1 small nuclear RNAs (U1snRNAs) occur in the nucleus of plants and animals where, complexed with several proteins in the form of U1 small nuclear ribonucleoprotein particles (U1snRNPs), they play an important role in precursor messenger RNA (pre-mRNA) splicing. Ten potato U1snRNA genes have been isolated on two genomic clones illustrating the clustering of this multigene family on the potato genome. Based on both the sequence of their coding regions and upstream regulatory elements, seven of the genes are potentially functional. The other three genes were pseudogenes with defective promoter or coding region sequences. Analysis of expression of individual cloned U1snRNA genes in transfected tobacco protoplasts was impossible due to the similarity of U1snRNA sequences in tobacco. However, by marking the coding regions with oligonucleotides or constructing chimaeric genes consisting of a potato U1snRNA promoter region and maize U5snRNA coding region, three of the U1 promoter regions were shown to be transcriptionally active.

Base Sequence

Rescue of a panel of Hemophilia A-causing 5'ss splicing mutations by unique Exon-specific U1snRNA variants.

BACKGROUND: Aberrant mRNA splicing is a well-established pathogenic mechanism for human disease, but its real impact is hardly predictable and underestimated. Splicing can be therefore modulated for therapeutic purposes, and splicing-switching molecules are in clinics for some diseases. Here, conscious that over 10% of all pathogenic mutations occurs at 5'ss, we aimed at characterizing and rescuing nine 5'ss mutations in three models of defective F8 exons whose skipping would lead to factor VIII (FVIII) deficiency (Hemophilia A), the most frequent coagulation factor disorder. METHODS: HEK293T cells were transfected with F8 minigene variants, alone or with engineered U1 small nuclear RNAs (U1snRNAs), and splicing patterns analysed via RT-PCR. RESULTS: All 5'ss mutations induced exon skipping, and the proportion of correct transcripts, not predictable by computational analysis, was consistent with residual FVIII levels in patients. For each exon we identified a unique engineered U1snRNAs, either compensatory or Exon Specific (ExSpeU1), able to rescue all mutations. Overall, ExSpeU1s were more effective than compensatory U1snRNAs, particularly in the defective exons 6 and 22. CONCLUSIONS: Data highlight the importance of splicing assays to elucidate genotype-phenotype relationships and proved the correction efficacy of ExSpeU1s for each targeted defective F8 exon, thus expanding their translational potential for HA.

Humans

Solution structure of human U1 snRNA. Derivation of a possible three-dimensional model.

The solution structure of human U1 snRNA was investigated by using base-specific chemical probes (dimethylsulfate, carbodiimide, diethylpyrocarbonate) and RNase V1. Chemical reagents were employed under various conditions of salt and temperature and allowed information at the Watson-Crick base-pairing positions to be obtained for 66% of the U1 snRNA bases. Double-stranded or stacked regions were examined with RNase V1. The dat gained from these experiments extend and support the previous 2D model for U1snRNA. However, to elucidate some aspects of the solution data that could not be accounted for by the secondary structure model, the information gathered from structure probing was used to provide the experimental basis required to construct and to test a tertiary structure model by computer graphics modeling. As a result, U1 snRNA is shown to adopt an asymmetrical X-shape that is formed by two helical domains, each one being generated by coaxial stacking of helices at the U1 snRNA cruciform. Chemical reactivities and model building show that a few nucleotides, previously proposed to be unpaired, can form A.G and U.U non Watson-Crick base-pairs, notably in stem-loop B. The structural model we propose for regions G12 to A124 integrates stereochemical constraints and is based both on solution structure data and sequence comparisons between U1 snRNAs.

Alkylating Agents