Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An HLA-E-specific oligonucleotide probe was used to study the expression of HLA-E. This probe detects two HLA-E transcripts, 1.8 and 2.7 kb in size, which are present in varying ratios in all tissues and cell lines investigated. We demonstrate that alternative poly(A) site usage accounts for the differential regulation of the two HLA-E mRNA species. Sequence analysis of three cDNA clones, representing the two transcripts of HLA-E, and of an HLA-E gene encoded by cosmid cd3.14, revealed identity of gene and cDNA in the 3' untranslated region. S1 nuclease protection assays confirmed that the two HLA-E transcripts are not alternative splicing products. Introduction of cd3.14, together with human beta 2 m into the murine myeloma cell line P3X63-Ag8.653, resulted in a cell surface expression of an HLA-class I heavy chain detectable by indirect immunofluorescence whereas transfection into the human beta 2m expressing mouse L cell line, J27 was negative with regard to cell surface expression. Cell surface labeling of transfectants and immunoprecipitation with a monomorphic HLA class I-specific antibody or an antibody against human beta 2m confirmed the presence of an HLA-E H chain on the cell surface. These results indicate that the HLA-E gene codes for a class I H chain that can be expressed on the cell surface.
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PMID:The HLA-E gene encodes two differentially regulated transcripts and a cell surface protein. 140 23

Treatment of cells with interferons induces various mRNAs and the corresponding proteins. We have described previously the isolation of a mouse cDNA clone (cDNA clone 202) which specifies an mRNA whose level is increased 20-fold in beta-interferon-treated Ehrlich ascites tumor cells. The increase is a consequence of an increased rate of transcription. The mRNA encodes a 56,000-dalton protein. We report here the isolation of a genomic clone including the 5' terminus of the 202 gene with the interferon-responsive region. Experiments involving primer extension and protection from cleavage by S1 nuclease revealed the existence of multiple 5' termini of 202 mRNAs in Ehrlich ascites tumor and Ltk- cells. Treatment with beta-interferon increased the level of these 202 mRNAs with different 5' termini nonuniformly. A 0.8-kilobase DNA segment from the 202 gene (including its 5' flanking region and its 5'-terminal exon) was ligated to the chloramphenicol acetyltransferase gene, and the resulting construct was transfected into mouse Ltk- cells. Treatment of these cells with beta-interferon increased the expression of the chloramphenicol acetyltransferase gene 5-10-fold. Within the first, untranslated exon of the 202 gene, we found a 29-nucleotide long sequence that is partially homologous to sequences which occur upstream from interferon-inducible human HLA and metallothionein IIA genes (Friedman, R. L., and Stark, G. R. (1985) Nature 314, 637-639).
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PMID:Interferons as gene activators. Cloning of the 5' terminus and the control segment of an interferon activated gene. 301 48

In order to determine the relative quantities of different HLA-A and -B mRNAs in cells, we have developed a simple and reliable method by using reverse transcription-polymerase chain reaction (RT-PCR), denaturing gradient gel electrophoresis (DGGE) and phosphor imaging analysis. Cytoplasmic RNA from lymphoblastoid cell lines with well-characterized HLA phenotypes are reversely transcribed with a primer specific for all HLA-A and -B antigens. The first-strand cDNA is used as template for quantitative PCR. The primer pair used for quantitative PCR are specific for all class I HLA and one of the primers is labeled with [gamma-32P]ATP. The amplified sequences include parts of exon 2 and exon 3 which contain most polymorphic residues in class I HLA molecules. The RT-PCR products containing the amplified HLA-A and -B sequences are separated by DGGE. The radioactivities of different DNA bands separated in denaturing gradient polyacrylamide gels are measured by phosphor imaging and used to determine the relative amounts of HLA-A and -B mRNAs. This approach is validated by using samples containing known quantities of different HLA-A and -B mRNA transcripts and confirmed by S1 nuclease protection assay. The combined RT-PCR/DGGE approach therefore provides a simple and reliable method for quantitation of relative amounts of different HLA-A and -B mRNAs in cells. This method should also be useful for studying the expression of other highly conserved and duplicated genes.
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PMID:Measurement of relative quantities of different HLA-A and -B mRNAs in cells by reverse transcription-polymerase chain reaction and denaturing gradient gel electrophoresis. 913 31