Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The possible involvement of the human T lymphotropic viruses type I and II (HTLV-I and -II) in lymphoproliferative disorders of mature T cells other than adult T cell leukemia/lymphoma (ATLL) has been controversial. Most studies have focused primarily on the cutaneous T cell lymphomas. However, skin involvement is a frequent feature of T prolymphocytic leukemia (T-PLL) and antibodies against HTLV-I and -II have been reported in individuals with large granular lymphocytic (LGL) leukemia. We examined 36 patients with T-PLL and 28 with LGL leukemia for evidence of HTLV-I and -II. Polymerase chain reaction (PCR) was performed on DNA from fresh peripheral blood mononuclear cells (PBMCs) and PBMCs after short-term culture (STC) using primers against all parts of the HTLV-I genome (LTR, gag, env, pol, tax/rex) and against HTLV-II pol and gag. Reverse transcriptase (RT) activity was measured on supernatants from STCs using a sensitive PCR-based technique. No HTLV-I or -II sequences were found by PCR nor RT activity detected in the 64 cases. Our findings do not provide evidence of HTLV-I or -II infection in T-PLL and LGL leukemia patients from an HTLV-I nonendemic area. Previous positive reports on these disorders may represent technical artefacts, detection of endogenous HTLV-like sequences or reflect patients from endemic areas and a variable etiology of T cell diseases.
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PMID:The human T-cell lymphotropic viruses types I/II are not involved in T prolymphocytic leukemia and large granular lymphocytic leukemia. 926 85

Biological, morphological and serological properties of grapevine berry inner necrosis virus (GINV), the casual virus of grapevine berry inner necrosis disease occurring in Japan, were compared with those of several known trichoviruses. Host range and particle length of GINV were quite similar to those of apple chlorotic leaf spot trichovirus (ACLSV). In ultrathin sections of the infected tissues, GINV particles existed in aggregated masses in the cytoplasm of vascular parenchyma and mesophyll cells. No virus specific inclusion bodies, such as pinwheels, viroplasmas or vesicles were observed. Serological relationships were not found between GINV and ACLSV, grapevine virus A or grapevine virus B. The cDNAs of the 3'-terminal region of the GINV genome were synthesized from poly (A)+RNAs extracted from infected tissues by PCR-selected cDNA subtraction and 3'-RACE PCR. The sequence of the 3'-terminal 2469 nucleotides contained three open reading frames (ORF) encoding a protein with the conserved motifs of RNA polymerase (ORF1), a 39 kDa putative movement protein (ORF2) and a 22 kDa protein (ORF3). The 22 kDa protein expressed in Escherichia coli reacted with antiserum against GINV, indicating that it is the coat protein of GINV. Polymerase and coat protein amino acid sequence comparisons and phylogenetic analyses with nine species of the genera Trichovirus and Capillovirus indicated that GINV is a new trichovirus relatively close to ACLSV.
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PMID:Grapevine berry inner necrosis, a new trichovirus: comparative studies with several known trichoviruses. 926 48

Two genes encoding manganese superoxide dismutase (sod-2 and sod-3) have been identified in the nematode Caenorhabditis elegans. Each gene is composed of five exons, and intron positions are identical; however, intron sizes and sequences are not the same. The predicted protein sequences are 86.3% homologous (91.8% conservative), and the cDNAs are only 75.2% homologous. Both deduced protein sequences contain the expected N-terminal mitochondrial transit peptides. Reverse transcriptase polymerase chain reaction analysis shows that both genes are expressed under normal growth conditions and that their RNA transcripts are trans-spliced to the SL-1 leader sequence. The latter result together with Northern blot analysis indicate that both genes have mono-cistronic transcripts. The sod-3 gene was mapped to chromosome X, and the location of sod-2 was confirmed to be chromosome I. Polymerase chain reaction was used to amplify the cDNA regions encoding the predicted mature manganese superoxide dismutase proteins and each was cloned and expressed to high levels in Escherichia coli cells deficient in cytosolic superoxide dismutases. Both proteins were shown to be active in E. coli, providing similar protection against methyl viologen-induced oxidative stress. The expressed enzymes, which were not inhibited by hydrogen peroxide or cyanide, are dimeric, show quite different electrophoretic mobilities and isoelectric points, but exhibit comparable specific activities.
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PMID:Cloning, expression, and characterization of two manganese superoxide dismutases from Caenorhabditis elegans. 935 32

Attempts were made to identify some of the subunits of the baculovirus-induced RNA polymerase following purification of its enzymatic activity by conventional chromatography. Polymerase activity was extracted from lysates of insect cells infected with Autographa californica multicapsid nucleopolyhedrovirus by polyethylenimine precipitation and subsequently purified by phosphocellulose, anion exchange, poly(A) Sepharose affinity, and gel filtration chromatography. The presence of the polymerase was monitored by its alpha-amanitin-resistant activity in in vitro transcription assays. A number of polypeptides associated with the enzymatic activity were identified. Peptide-specific antibodies were generated against a variety of late-expression factors (LEFs) and these antibodies, along with antisera directed against several other baculovirus proteins, were used in an immunoblot analysis of the purified polymerase. The results revealed that both the viral helicase (p143) and the virogenic stroma protein, pp31, copurify with the baculovirus-induced RNA polymerase activity through several chromatographic steps and may be loosely associated with the RNA polymerase. LEF8, LEF9 and p78/83, a nucleocapsid-associated phosphoprotein, were found to associate with the viral-induced polymerase activity. LEF8 and LEF9 contain regions of sequence homology with components of other DNA-directed RNA polymerases, while a portion of p78/83 exhibits some homology to the sigma factor of bacterial RNA polymerase, the RAP30 protein found in the mammalian transcription complex TFIIF, and the RAP94 polypeptide associated with vaccinia virus RNA polymerase. The p78/83 protein has previously been shown by our laboratory to be a capsid protein, but it may also play some role with the RNA polymerase. These results represent a first attempt to identify specific components of the RNA polymerase associated with infections of insect cells by A. californica nucleopolyhedrovirus.
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PMID:The late expression factors 8 and 9 and possibly the phosphoprotein p78/83 of Autographa californica multicapsid nucleopolyhedrovirus are components of the virus-induced RNA polymerase. 970 63

The integrin IIbbeta3 mediates platelet aggregation through its fibrinogen and adhesive protein-binding properties. Particular interest concerns the role of the cytoplasmic domains of IIb and beta3. We now report the molecular analysis of IIbbeta3 from a patient with a Glanzmann's thrombasthenia-like syndrome for whom the principal characteristics are an approximate 50% total platelet content of IIbbeta3 but with a much lower proportion in the surface pool (Hardisty et al, Blood 80:696, 1992). Polymerase chain reaction (PCR) single-strand conformational polymorphism and DNA sequencing showed a heterozygous mutation giving rise to amino acid substitution R995 to Q in the GFFKR sequence of the cytoplasmic domain of IIb. Reverse transcriptase-PCR and polymorphism analysis only detected mRNA for the mutated allele of the IIb gene and a single allele of the beta3 gene in his platelets, suggesting other unidentified defects. Site-directed mutagenesis followed by transient expression of the mutated IIb together with wild-type beta3 in Cos-7 cells resulted in a markedly decreased expression of the complex at the cell surface when compared with cells transfected with wild-type IIb and beta3. Flow cytometry with PAC-1 and a stable Chinese hamster ovary-transfected cell line showed that the mutated receptor was not locked into a high activation state, although it became so in the presence of the activating antibody, anti-LIBS6. This is the first reported natural mutation in the highly conserved GFFKR sequence of the IIb cytoplasmic domain.
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PMID:R to Q amino acid substitution in the GFFKR sequence of the cytoplasmic domain of the integrin IIb subunit in a patient with a Glanzmann's thrombasthenia-like syndrome. 983 22

Polymerase chain reaction (PCR)-based nucleotide sequence analysis was performed in 12 cases of Ewing sarcoma on the cDNA and/or genomic DNA breakpoint regions of a t(11;22)(q24;q12), which joins the EWS gene located on chromosome 22 with the FLI1 gene located on chromosome 11, in order to understand the molecular mechanism of this translocation. Reverse transcriptase-PCR on total tumor cell RNA from the examined cases showed five types of EWS-FLI1 chimeric product, resulting from various junctions between EWS exon 7 or 10 with FLI1 exon 5, 6, or 8. Sequencing of the genomic fusion junctions of EWS-FLI1 in seven cases showing three types of the chimeric cDNA products revealed that most of the breakpoint junctions shared common nucleotide(s) from both genes, and that the breakpoints in EWS introns 7 and 10 clustered within 100 bp and 300 bp, respectively. All the junctions were found to be flanked by various oligomers, among which a consensus sequence, 5'-AGAAAARDRR-3', was found near the breakpoints of both genes in four cases, suggesting that these oligomers may have a functional significance in the genesis of t(11;22). In addition to these oligomers, sequences highly homologous to Alu repeats and/or eukaryotic topoisomerase II cleavage sites were located near, or flanked, or even encompassed, the breakpoints in most of the cases examined. Thus, these sequences may also mediate DNA double-strand breakage and rejoining to generate the t(11;22). Genomic sequence analysis of both EWS-FLI1 and FLI1-EWS chimeric genes in three of the seven cases demonstrated a deletion and duplication of both EWS and FLI1 sequences in two cases and no gain or loss in one case. The present findings suggest that multiple mechanisms may be operative for the break and rejoining of the fragments of chromosomes 11 and 22 in the genesis of t(11;22), and that some of these translocations are asymmetric at the molecular level.
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PMID:Molecular characterization of the genomic breakpoint junction in a t(11;22) translocation in Ewing sarcoma. 1022 34

ABC10alpha is a small polypeptide shared by the three yeast RNA polymerases. Homologous polypeptides in higher eukaryotes have a zinc-binding CX(2)C. CX(2)C motif and a conserved basic C-terminal end. These features are also found in archaeal gene products that may encode an RNA polymerase subunit. The CX(2)C. CX(2)C motif is partly dispensable, since only its first cysteine is essential for growth, whereas the basic C-terminal end is critical in vivo. A mutant in the latter domain has an RNA polymerase III-specific defect and, in vitro, impairs RNA polymerase III assembly. Polymerase activity was, however, not affected in various faithful transcription assays. The mutant is suppressed by a high gene dosage of the second largest subunit of RNA polymerase III, whereas the homologous subunits of RNA polymerase I and II have aggravating effects. In a two-hybrid assay, ABC10alpha binds to the C-terminal half of the second largest subunit of RNA polymerase I, in a way that requires the integrity of the CX(2)C. CX(2)C motif. Thus, ABC10alpha appears to interact directly with the second largest subunit during polymerase assembly. This interaction is presumably a major rate-limiting step in assembly, since diploid cells containing only one functional gene copy for ABC10alpha have a partial growth defect.
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PMID:Functional characterization of ABC10alpha, an essential polypeptide shared by all three forms of eukaryotic DNA-dependent RNA polymerases. 1053 51

Mycobacteria are intracellular pathogens that survive and grow in host macrophages. Following phagocytosis, sustained intracellular bacterial growth depends on its ability to avoid destruction by macrophage-mediated host defences such as lysosomal enzymes, reactive oxygen and the reactive nitrogen intermediates. This suggests that the interaction between host cell and microbe is delicately balanced, and can be tipped in favour of either organism. The identification of Mycobacterium tuberculosis H37Rv (MTB) genes expressed within host cells would contribute greatly to the development of new strategies to fight tuberculosis. In the present study, we compared MTB gene expression in the course of intra- (human macrophages) and extracellular growth (Sauton's medium) to ascertain whether differences might occur between gene-expression patterns in the two habitats of replication. Using reverse-transcriptase polymerase chain reaction (RT-PCR) on a group of 14 MTB-Complex-specific genes, we found that MT10Sa (a small stable RNA), 35 kDa (unknown), ahpC (alkyl hydroperoxide reductase, AhpC), sigF (alternative RNA Polymerase sigma factor), and katG (catalase-peroxidase, HPI) genes are expressed in both the environments, while Ag85B, Ag85C (members of the Antigen 85 Complex), rpoV (RNA Polymerase sigma factor) and ESAT6 (early secretory antigen, 6 kDa) are expressed only in the in vitro culture; on the other hand, Ag85A (Antigen 85 Complex), rpoB (RNA Polymerase beta sub-unit), pab (Protein antigen b), invA and invB genes (encoding proteins that show homologies with p60 of Listeria monocytogenes) are expressed only inside the macrophage. Positive RT-PCR products on cDNAs for these genomic regions were not obtained from approximately 1000-fold more bacteria grown in Laboratory Broth. Identification of M. tuberculosis genes expressed in response to phagocytosis by human macrophages increases our basic understanding of the host-pathogen interaction, and helps to identify bacterial factors necessary for in vivo survival and growth.
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PMID:Mycobacterium tuberculosis H37Rv comparative gene-expression analysis in synthetic medium and human macrophage. 1094 May 66

Numerous renal abnormalities accompany thyroid disease, most of which have been ascribed to the effects of thyroid hormone on renal metabolism. In the present report, we investigate the renal expression of the nominally thyroid-specific proteins, thyroid-stimulating hormone (TSH) receptor (TSHR) and thyroglobulin (Tg), as potential links between renal and thyroid function. The expression of TSHR has been identified in several extrathyroidal tissues, but its presence in the kidney remains controversial. We have used reverse-transcriptase polymerase chain reaction and DNA sequencing to demonstrate the presence of TSHR transcript in human and mouse kidney, in a primary culture of human kidney, and in a green monkey kidney epithelioid cell line. Furthermore, human kidney cells responded to TSH with a 2.5- fold increase in intracellular cyclic adenosine monophosphate, suggesting the presence of functional TSHR protein. Comparison of renal expression of TSHR in a bovine growth hormone transgenic mouse model of progressive glomerulosclerosis with control mice suggested increased TSHR transcript in the renal cortex of transgenic animals. TSHR transcript was also detected in mouse mesangial cells in vitro which responded to TSH with significant increases in the formation of three-dimensional hillhocks. Polymerase chain reaction also confirmed the presence of Tg transcript in human and mouse kidneys and in mouse mesangial cells, but no effect of either TSH or cyclic adenosine monophosphate on Tg transcript levels could be discerned. Immunofluorescent staining with a monoclonal anti-Tg antibody identified positive staining in the cytoplasm of mesangial cells. These data suggest that the kidney is capable of expressing the thyroid-specific genes, TSHR and Tg, which could conceivably mediate effects of thyroid disease in the kidney.
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PMID:Renal expression of two 'thyroid-specific' genes: thyrotropin receptor and thyroglobulin. 1094 Jul 22

We showed previously that the WW domain of the prolyl isomerase, Ess1, can bind the phosphorylated carboxyl-terminal domain (phospho-CTD) of the largest subunit of RNA Polymerase II. Analysis of phospho-CTD binding by four other WW domain-containing Saccharomyces cerevisiae proteins indicates the splicing factor, Prp40, and the RNA polymerase II ubiquitin ligase, Rsp5, can also bind the phospho-CTD. The identification of Prp40 as a phospho-CTD binding protein represents the first demonstration of direct interaction between a documented splicing factor and the phospho-CTD. Domain dissection studies reveal that phospho-CTD binding occurs at multiple locations in Prp40, including sites in both the WW and FF domain regions. Because the conserved repeats of the CTD make it an ideal ligand for multi-site binding events, the implications of multi-site binding are discussed. Our data suggest a mechanism by which the phospho-CTD of elongating RNA polymerase II facilitates commitment complex formation by juxtaposing the 5' and 3' splice sites.
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PMID:The splicing factor, Prp40, binds the phosphorylated carboxyl-terminal domain of RNA polymerase II. 1097 20


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