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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The review presents the results of investigations of single-stranded DNAs of viruses, bacteria and cells of higher organisms. Methods of revealing, isolating and analysis of these DNAs are presented. A large variety of single-stranded DNA containing genomes of plant and animal viruses was revealed. Attention is drawn to the integration and replication of viral genomes. Results of SV40 integration during the first two days after infection of Chinese hamster cells are shown. Results of studying multi-copy single-stranded DNA in bacterial cells were analysed. In separate sections, the replication of plasmid single-stranded DNA was studied as well as the problem of plasmid stability in cells. Advances in bacteria transformation studies are stated. Data of single-stranded DNA investigation in cells of higher organisms are mainly presented on the example of early embryos. Data on the analysis of gene hypersensitivity to nuclease S1 are given. A table of proteins destabilizing and unweaving single-stranded DNA and a classification table of proteins bound with single-stranded DNA according to their functional significance are presented. It is stated that the problem of single-stranded DNA significance in cells remains open, although some results have been achieved.
Mol Biol (Mosk)
PMID:[Single-stranded DNA from viruses, prokaryotes and eukaryotes]. 150 72

The src family gene lyn is expressed preferentially in B lymphocytes but very little in normal T lymphocytes. Transcription of the lyn gene in T lymphocytes was shown to be induced by the p40tax protein encoded by human T-cell lymphotropic virus type I. For determination of the mechanism of p40tax-mediated trans activation, the transcriptional promoter region of the lyn gene was characterized. By endonuclease S1 mapping, the transcriptional initiation sites were identified within the 770-bp EcoRI-SacI fragment of the 5'-terminal portion of the human lyn gene. This fragment showed promoter activity when placed upstream of the bacterial chloramphenicol acetyltransferase gene and transfected into various cell lines. Nucleotide sequence analysis revealed that the lyn promoter region contained four GC box-like sequences but not a TATA or CCAAT box. In addition, it contained sequences characteristic of a cyclic AMP-responsive element, octamer-binding motif, PEA3-like motifs, and NF kappa B-binding motif-like sequence. Mutational analysis suggested that the octamer-binding motif sequence is of primary importance for the lyn promoter activity but that the other elements are not. Cotransfection of various chloramphenicol acetyltransferase constructs containing different length of the lyn promoter together with p40tax expression plasmids into Jurkat T cells showed that the sequence responsible for p40tax-induced transcription is present around the transcription initiation sites.
Mol Cell Biol 1992 Sep
PMID:Characterization of the promoter region of the src family gene lyn and its trans activation by human T-cell leukemia virus type I-encoded p40tax. 150 84

Three mitochondrial plasmids (1704, 1695 and 1478 bp) were isolated from sterile cytoplasms of Vicia faba L. and cloned into a bacterial plasmid vector. Their nucleotide sequence was found to be 99 to 100% homologous to their counterparts isolated from a fertile cytoplasm (J.A. Wahleithner and D.R. Wolstenholme, Curr Genet 12 (1987) 55-76). Several overlapping transcripts were localized in the region which is unique to each of the three plasmids. S1 nuclease mapping indicated for all of them several 3' termini but a unique 5' boundary which was located downstream of the consensus sequence CNTAAGTGANNNNNGAA also found at the transcript 5' boundary of other plant mitochondrial plasmids. Southern blot hybridization with nuclear DNA indicated the presence of nuclear sequences homologous to each plasmid.
Plant Mol Biol 1992 Sep
PMID:Sequence and transcription analysis of mitochondrial plasmids isolated from cytoplasmic male-sterile lines of Vicia faba. 151 Nov 37

Rats and mice both express two, non-allelic, insulin genes. In the rat the ratio of the two preproinsulin mRNAs closely matches that of the mature insulin peptides. The experiments reported here demonstrate that this is not the case in the mouse. The relative amounts of the two murine proinsulin RNAs were measured by an S1 nuclease assay. The ratio of preproinsulin I mRNA to preproinsulin II mRNA was 4:1 in RNA extracted from the pancreas of mice fed ad libitum or fasted for 72 h. A similar value was found in mouse islets of Langerhans after maintenance in tissue culture for 48 h at either 2.8 or 16.7 mM glucose. The ratio of insulin I:insulin II peptides, assessed by separating the two insulins using reversed phase high-performance liquid chromatography, was approximately 1:3 in both pancreas and islets. Thus in the mouse, unlike the rat, the ratio of the two insulin peptides does not reflect that of the two preproinsulin mRNAs.
Mol Cell Endocrinol 1992 Aug
PMID:The ratio of mouse insulin I:insulin II does not reflect that of the corresponding preproinsulin mRNAs. 151 87

The small subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) in the French bean Phaseolus vulgaris L. is encoded by a small gene family consisting of a minimum of three members. Three small subunit genes (rbcS genes) represented in a light-grown primary leaf cDNA library were characterised by sequencing two cDNAs which were full-length and one which was deficient in part of the sequence encoding the transit peptide. The cDNA clones are identical in their coding sequences, for both the transit peptide and the mature polypeptide, but divergent in their untranslated sequences. The derived amino acid sequence is very similar to that reported for other species, although the first amino acid of the mature polypeptide is isoleucine, which differs from the methionine found in all other higher plant rbcS genes. Surprisingly, one of the cDNA clones contains two introns, which are at positions conserved in rbcS genes from other species. It is concluded that this cDNA resulted from the cloning of an unprocessed transcript. Alternative polyadenylation sites are found for two of the genes. Expression of the rbcS genes in the primary leaves is stimulated by light, although transcripts can readily be detected in dark-grown leaves. Expression is also organ-specific, as in other species. The frequency of cDNA clones in the library indicates that the different genes show quantitative differences in expression and S1 nuclease analysis suggests that individual rbcS genes are photoregulated.
Plant Mol Biol 1992 Feb
PMID:Genes encoding the small subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase in Phaseolus vulgaris L.: nucleotide sequence of cDNA clones and initial studies of expression. 153 29

Both PHO80 and PHO85 genes are required to establish the repressed state of the PHO system of Saccharomyces cerevisiae. S1 nuclease protection analysis of the PHO85 transcript revealed that the PHO85 gene contains an intron at the 6th codon of the gene. Each of the fusion proteins, LacZ-Pho80 and LacZ-Pho85, was produced into Escherichia coli and used as an antigen to raise antibodies in a rabbit. Using the affinity-purified antibodies in Western blotting experiments, the PHO85 protein was detected as a 36 kDa and the PHO80 protein as a 34 kDa protein. The PHO80 protein was detected only in extracts prepared from an overproducing strain. The immunoprecipitate containing the PHO85 protein showed protein kinase activity suggesting that PHO85 is a protein kinase gene, which is consistent with the observation that the deduced amino acid sequence of the PHO85 protein resembles that of some protein kinases. The PHO80 protein was found to be phosphorylated in the presence of PHO85 protein.
Mol Gen Genet 1992 Feb
PMID:Negative regulators of the PHO system of Saccharomyces cerevisiae: characterization of PHO80 and PHO85. 153 98

Human beta zero-thalassemic beta-globin genes harboring either a frameshift or a nonsense mutation that results in the premature termination of beta-globin mRNA translation have been previously introduced into the germ line of mice (S.-K. Lim, J.J. Mullins, C.-M. Chen, K. Gross, and L.E. Maquat, EMBO J. 8:2613-2619, 1989). Each transgene produces properly processed albeit abnormally unstable mRNA as well as several smaller RNAs in erythroid cells. These smaller RNAs are detected only in the cytoplasm and, relative to mRNA, are longer-lived and are missing sequences from either exon I or exons I and II. In this communication, we show by using genetics and S1 nuclease transcript mapping that the premature termination of beta-globin mRNA translation is mechanistically required for the abnormal RNA metabolism. We also provide evidence that generation of the smaller RNAs is a cytoplasmic process: the 5' ends of intron 1-containing pre-mRNAs were normal, the rates of removal of introns 1 and 2 were normal, and studies inhibiting RNA synthesis with actinomycin D demonstrated a precursor-product relationship between full-length mRNA and the smaller RNAs. In vivo, about 50% of the full-length species that undergo decay are degraded to the smaller RNAs and the rest are degraded to undetectable products. Exposure of erythroid cells that expressed a normal human beta-globin transgene to either cycloheximide or puromycin did not result in the generation of the smaller RNAs. Therefore, a drug-induced reduction in cellular protein synthesis does not reproduce this aspect of cytoplasmic mRNA metabolism. These data suggest that the premature termination of beta-globin mRNA translation in either exon I or exon II results in the cytoplasmic generation of discrete mRNA degradation products that are missing sequences from exon I or exons I and II. Since these degradation products appear to be the same for all nonsense codons tested, there is no correlation between the position of translation termination and the sites of nucleolytic cleavage.
Mol Cell Biol 1992 Mar
PMID:Nonsense codons in human beta-globin mRNA result in the production of mRNA degradation products. 154 96

Previously we have demonstrated the existence of stable transcripts from the noncoding strand of a rearranged c-myc gene in murine plasmacytomas in which the oncogene has translocated to an immunoglobulin constant-region gene element (M. Dean, R. B. Kent, and G. E. Sonenshein, Nature [London] 305:443-446, 1983). The resulting RNAs are chimeric, containing c-myc antisense and immunoglobulin sense sequences. A normal unrearranged murine c-myc gene is transcribed in the antisense orientation throughout much of the gene; however, stable transcripts have not been detected. In this study, using Northern (RNA) blot, S1 nuclease, and primer extension analyses, we have mapped the 5' end of the stable chimeric transcripts to a site 175 bp from the start of exon 3, within intron 2 of the c-myc gene. In vitro transcription assays with constructs containing this site and 400 bp upstream, in the antisense orientation, and nuclear extracts from plasmacytoma cells, as well as a number of cell lines with normal unrearranged c-myc genes, indicated that this promoter was functional. This finding was confirmed in transient transfection assays using the antisense promoter linked to the chloramphenicol acetyltransferase reporter gene. These results suggest that a normal promoter of antisense transcription is used following c-myc gene translocation.
Mol Cell Biol 1992 Mar
PMID:An antisense promoter of the murine c-myc gene is localized within intron 2. 154 13

Genomic clones representing S1 and S3 alleles of the self-incompatibility locus (S locus) in Petunia inflata have been isolated and characterized. Extensive lengths of the flanking regions as well as the coding regions contained in both clones have been sequenced. Both alleles have a single, relatively short intron located within a region of high interallelic variability. Transcription start sites of both alleles have been determined by S1 nuclease mapping, and putative TATA boxes have been identified. Nucleotide sequence comparison of the two alleles shows a high level of diversity in the regions immediately flanking the coding region. Southern analysis demonstrates that this sequence diversity extends beyond the regions which have been sequenced, such that the two clones appear to be completely heterogeneous except for conserved sites within the coding regions of the two alleles. These analyses also reveal the presence of repetitive sequences which are very closely associated with the coding regions of both alleles. The influence of these characteristics on genetic recombination and the maintenance of allelic independence, as well as the organization of the S locus, are discussed.
Plant Mol Biol 1992 Feb
PMID:The flanking regions of two Petunia inflata S alleles are heterogeneous and contain repetitive sequences. 155 46

A break was identified in the large subunit ribosomal RNA of Trichinella spiralis that results in its dissociation into 2 smaller fragments of approximately equal length. The approximate location of the break within the encoding gene was mapped from subcloned rDNA fragments by S1 protection experiments. The boundaries of the break were determined by cDNA primer extension and S1 nuclease protection assays. The excised fragment (gap sequence) was localized to expansion segment 5 within domain IV from which 86 bases are removed during the excision process. The gap region is flanked by the consensus sequence CGAAAG; however, comparison of expansion segment 5 sequences from T. spiralis, T. nativa, T. nelsoni and T. pseudospiralis, all of which undergo 'gap processing', demonstrates significant size and sequence heterogeneity and provides little evidence for additional consensus sequences which could be implicated in gap processing.
Mol Biochem Parasitol 1992 Apr
PMID:The identification and characterization of a break within the large subunit ribosomal RNA of Trichinella spiralis: comparison of gap sequences within the genus. 157 86


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