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Biomedical subjects

M R Kenealy

Publications and source records attributed to M R Kenealy.

7 recordsLinked to original sources
PubMed2000

The 3'-untranslated region of the human estrogen receptor alpha gene mediates rapid messenger ribonucleic acid turnover.

Human estrogen receptor-alpha messenger RNA (hERalpha mRNA) has a relatively short half-life, which was determined to be approximately 5 h in MCF-7 cell line after actinomycin D treatment. The 3'-untranslated region (3'UTR) of hERalpha mRNA was previously shown to completely down-regulate chloramphenicol acetyltransferase activity when present at the 3'-end of chloramphenicol acetyltransferase transcripts, suggesting a destabilizing function of the hERalpha 3'UTR sequence. Chimeric genes composed of a serum-inducible Fos promoter, GH-coding sequences, and different segments of the hERalpha complementary DNA 3'UTR sequence were used to confirm this hypothesis and to localize the RNA region responsible for the destabilizing effect. The presence of the complete hERalpha 3'UTR reduced the half-life of the reporter mRNA from more than 24 to 3 h. When the hERalpha 3'UTR was subdivided into four fragments (UTR1-4), one fragment, UTR2, retained the most ability to down-regulate the reporter mRNA (t1/2 = 4 h). A stretch of four AUUUA motifs within UTR2 was shown not to mediate mRNA destabilization. In contrast, further subdivision of the UTR2 into three parts (UTR2a-c) resulted in the loss of the destabilizing activity. Finally, recombination of two UTR2 subfragments (UTR2a and -b) partially restored this function, indicating a cooperative role among the three UTR2a-c subfragments in the process that leads to destabilization of the hERalpha transcript.

3' Untranslated Regions↗
PubMed1998

Systematic genomic screening and analysis of mRNA in untranslated regions and mRNA precursors: combining experimental and computational approaches.

MOTIVATION: The untranslated regions (UTRs) of mRNA upstream (5'UTR) and downstream (3'UTR) of the open reading frame, as well as the mRNA precursor, carry important regulatory sequences. To reveal unidentified regulatory signals, we combine information from experiments with computational approaches. Depending on available knowledge, three different strategies are employed. RESULTS: Searching with a consensus template, new RNAs with regulatory RNA elements can be identified in genomic screens. By this approach, we identify new candidate regulatory motifs resembling iron-responsive elements in the 5'UTRs of HemA, FepB and FrdB mRNA from Escherichia coli. If an RNA element is not yet defined, it may be analyzed by combining results from SELEX (selective enrichment of ligands by exponential amplification) and a search of databases from RNA or genomic sequences. A cleavage stimulating factor (CstF) binding element 3 of the polyadenylation site in the mRNA precursor serves as a test example. Alternatively, the regulatory RNA element may be found by studying different RNA foldings and their correlation with simple experimental tests. We delineate a novel instability element in the 3'UTR of the estrogen receptor mRNA in this way. AVAILABILITY: Strategy, methods and programs are available on request from T.Dandekar. CONTACT: dandekar@embl-heidelberg.de

3' Untranslated Regions↗
PubMed1997

Improved efficiency for primer extension by using a long, highly-labeled primer generated from immobilized single-stranded DNA templates.

Primer extension is one of the most common methods used to measure the amount and size of RNAs. We demonstrate that the sensitivity and the specificity of this method are improved considerably by using a highly-labeled single-stranded DNA generated from a biotinylated single-stranded DNA template, as a long specific primer in the reverse transcription reaction. This new approach allows the detection of transcripts with a low expression level from microgram quantities of total RNA.

Animals↗
PubMed1993

Detection of both the normal and mutant alleles in single cells of individuals heterozygous for the sickle cell mutation--prelude to preimplantation diagnosis.

As a preliminary step to preimplantation diagnosis of sickle cell disease in unfertilized eggs or 8-cell embryos of heterozygous parents, we established quality control for detection of the mutant and normal alleles of the beta-haemoglobin gene using single buccal cells. Efficient polymerase chain reaction (PCR) amplification of a 680 base pair sequence of the beta-globin gene spanning the site of the sickle cell mutation was obtained for 79 per cent of single heterozygous cells. In 71 per cent of cases, both alleles were detected. With this current efficiency, we predict that a clinical preimplantation diagnosis at the 8-cell embryo stage could be carried out safely and reliably for a couple at risk of transmitting sickle cell disease to their children.

Alleles↗