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 sigma S subunit of RNA polymerase is the master regulator of a regulatory network that controls stationary-phase induction as well as osmotic regulation of many genes in Escherichia coli. In an attempt to identify additional regulatory components in this network, we have isolated Tn10 insertion mutations that in trans alter the expression of osmY and other sigma S-dependent genes. One of these mutations conferred glucose sensitivity and was localized in pgi (encoding phosphoglucose isomerase). pgi::Tn10 strains exhibit increased basal levels of expression of osmY and otsBA in exponentially growing cells and reduced osmotic inducibility of these genes. A similar phenotype was also observed for pgm and galU mutants, which are deficient in phosphoglucomutase and UDP-glucose pyrophosphorylase, respectively. This indicates that the observed effects on gene expression are related to the lack of UDP-glucose (or a derivative thereof), which is common to all three mutants. Mutants deficient in UDP-galactose epimerase (galE mutants) and trehalose-6-phosphate synthase (otsA mutants) do not exhibit such an effect on gene expression, and an mdoA mutant that is deficient in the first step of the synthesis of membrane-derived oligosaccharides, shows only a partial increase in the expression of osmY. We therefore propose that the cellular content of UDP-glucose serves as an internal signal that controls expression of osmY and other sigma S-dependent genes. In addition, we demonstrate that pgi, pgm, and galU mutants contain increased levels of sigma S during steady-state growth, indicating that UDP-glucose interferes with the expression of sigma S itself.
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PMID:UDP-glucose is a potential intracellular signal molecule in the control of expression of sigma S and sigma S-dependent genes in Escherichia coli. 781 31

This paper reports the DNA sequence and analysis of an 11.7 kb segment localized on the right arm of Saccharomyces cerevisiae chromosome II. This fragment contains one incomplete and five long and non-overlapping open reading frames (ORFs) designated from centromere to telomere-proximal side as: YBR1406, 1409, 1410, 1411, 1412 and 1413. YBR1406 corresponds to the 5' end to PG11 encoding phosphoglucoisomerase. YBR1410 encodes a polypeptide of 798 amino acids whose C terminus contains five repeats (WD-40 repeat) similar to those found in the beta-subunits of G proteins and different yeast proteins such as Tup1, Prp4 and Cdc4. The higher similarity score is obtained with dTAFII80, a component of the RNA polymerase II transcriptional complex TFIID. YBR1411 encodes a polypeptide of 464 amino acids which belongs to the family of alpha-mannosyltransferases: KRE2/MNT1, KTR1, KTR2, YUR1 and the product of previously sequenced ORF YBR1445. YBR1412 corresponds to BEM1. The two ORFs, YBR1409 and YBR1413, which do not exhibit significant similarity with any known coding sequences, define new genes.
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PMID:Nucleotide sequence analysis of an 11.7 kb fragment of yeast chromosome II including BEM1, a new gene of the WD-40 repeat family and a new member of the KRE2/MNT1 family. 797 99

Using homologous recombination, both EKLF alleles in murine embryonic stem (ES) cells were inactivated. These EKLF-/- ES cells were capable of undergoing in vitro differentiation to form definitive erythroid colonies that were similar in size and number to those formed by wild-type ES cells. However, the EKLF-/- colonies were poorly hemoglobinized and enucleated erythrocytes in these colonies contained numerous Heinz bodies. Reverse transcriptase-polymerase chain reaction (RT-PCR) analyses revealed that adult and embryonic globin genes were appropriately regulated, with the exception of beta h1-globin, which continued to be expressed at a very low level. The ratio of adult beta-globin/alpha-globin mRNA in the mutant ES cells was 1/15 of that in wild-type ES cells. When the EKLF-/- cells were injected into blastocysts, they did not contribute at a detectable level to the mature erythrocyte compartment of the chimeric animals, based on analysis of glucose phosphate isomerase-1 (GPI-1) isozymes and hemoglobins that distinguish ES cell-derived erythrocytes from host blastocyst-derived erythrocytes. In contrast, semiquantitative RT-PCR analysis of RNA from reticulocytes of the same chimeric animals suggested that the ES cell-derived reticulocytes were present at a level of 6% to 8%. This indicated that the EKLF-/- erythrocytes in adult animals must be short-lived, apparently due to the imbalance of beta-versus alpha-globin chains, leading to the precipitation of excess alpha-globin chains to form Heinz bodies. Consistent with this hypothesis, the short life span was ameliorated by introduction into the EKLF-/- ES cells of a human LCR/gamma-globin gene, as evidenced by the presence of ES cell-derived reticulocytes as well as mature erythrocytes in the blood of the chimeric animals.
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PMID:A shortened life span of EKLF-/- adult erythrocytes, due to a deficiency of beta-globin chains, is ameliorated by human gamma-globin chains. 924 64

Long noncoding RNAs (lncRNAs) significantly influence the development and regulation of genome expression in cells. Here, we demonstrate the role of lncRNA ceruloplasmin (NRCP) in cancer metabolism and elucidate functional effects leading to increased tumor progression. NRCP was highly upregulated in ovarian tumors, and knockdown of NRCP resulted in significantly increased apoptosis, decreased cell proliferation, and decreased glycolysis compared with control cancer cells. In an orthotopic mouse model of ovarian cancer, siNRCP delivered via a liposomal carrier significantly reduced tumor growth compared with control treatment. We identified NRCP as an intermediate binding partner between STAT1 and RNA polymerase II, leading to increased expression of downstream target genes such as glucose-6-phosphate isomerase. Collectively, we report a previously unrecognized role of the lncRNA NRCP in modulating cancer metabolism. As demonstrated, DOPC nanoparticle-incorporated siRNA-mediated silencing of this lncRNA in vivo provides therapeutic avenue toward modulating lncRNAs in cancer.
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PMID:Long Noncoding RNA Ceruloplasmin Promotes Cancer Growth by Altering Glycolysis. 2668 30

Allotetraploid plant species combine the genomes of related diploid species, but little is known about whether homologous genes from the diploid genomes are expressed, how they interact, or whether they evolve differently when in a common tetraploid nucleus. Polyploidy may lead to gene silencing, but few molecular characterizations of silenced genes encoding enzymes in polyploids and related diploids have been reported. Here we describe the PgiC genes in the tetraploid Clarkia gracilis and related diploid species, which are native from California to southern Washington. PgiC encodes the cytosolic isozyme of phosphoglucose isomerase (PGIC; EC 5.3.1.9). The gene was duplicated in the basal stock of Clarkia and now both genes, PgiC1 and PgiC2, are active in about half of the diploid species, whereas only PgiC1 is active in the others. Clarkia gracilis was found to have three PgiC genes: two PgiC1s and a PgiC2. Reverse-transcriptase-polymerase chain reaction (RT-PCR) experiments, starting with mRNAs prepared from seedling leaves of C. gracilis, showed that the three genes are expressed. Analysis of their sequences showed they are evolving at similar rates to their homologues and that they have the same intron-exon structure. The presence of an expressed PgiC2 in C. gracilis was unexpected because all related diploid species, including one identified as a parent, have only active PgiC1s. The donor of the PgiC2 is now presumed extinct, but parsimony analysis identified its phylogenetic position. None of the PgiC genes that were active when C. gracilis arose were silenced. A possible example of gene conversion involving a 300-nuclectide region of one PgiC1 and PgiC2 was identified, but it probably occurred in the diploid parental species rather than in C. gracilis. PgiC2 is the first known example of an active locus in a tetraploid plant species that is no longer expressed in its diploid relatives.
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PMID:MOLECULAR CHARACTERIZATION OF PgiC IN A TETRAPLOID PLANT AND ITS DIPLOID RELATIVES. 2856 13