Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peroxisome proliferators (PP) are known hepatocarcinogens in rats and mice. We have investigated the ability of Wyeth-14 643 (Wy), a PP and potent rodent carcinogen, to induce replicative DNA synthesis and to modulate the levels of peroxisome proliferator activated receptor-alpha (PPAR alpha) transcriptionally-dependent genes in primary rat hepatocyte (HPC) cultures and hepatocyte/nonparenchymal cell (HPC/NPC) co-cultures maintained on Matrigel. Four days after plating, cells were treated with Wy and replicative DNA synthesis was quantitated using [3H]thymidine incorporation and specific mRNA transcript levels were determined by reverse-transcriptase polymerase chain reaction (RT-PCR). An increase in HPC replicative DNA synthesis was detected at 48 h in both Wy-treated HPC and HPC/NPC co-cultures relative to controls. This increase was approximately 3- and 6-fold in HPC and HPC/NPC cultures respectively, and was Wy concentration-dependent. The levels of PPAR alpha-transcriptionally dependent genes [cytochrome P4504A1, acyl-CoA oxidase (AOxase), and liver-fatty acid binding protein (L-FABP)] transcripts were determined as indicators of PPAR alpha activation. These transcripts increased dose-dependently at 48 h in HPC/NPC cultures up to 10 microM Wy. Similarly, RT-PCR product levels were also increased in HPC cultures with 10 microM Wy at 48 h. In conclusion, we have investigated the transcription of PPAR alpha-dependent genes and HPC replicative DNA synthesis by Wy in HPC/NPC co-cultures. Results of this work are clearly more reflective of the known in vivo effects of PP and suggest that HPC/NPC co-cultures are more appropriate than HPC cultures for such studies. The effect of PP on human HPC/NPC co-cultures is currently being investigated in our laboratory in an attempt to assess human risks to these chemicals more directly.
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PMID:Induction of replicative DNA synthesis and PPAR alpha-dependent gene transcription by Wy-14 643 in primary rat hepatocyte and non-parenchymal cell co-cultures. 939 5

To try to elucidate the relationship between the radiosensitivity of NPC cell lines and ATM gene, this study was designed to investigate the mutation of ATM/PI3K region in NPC cell lines with different radiosensitivity. Two NPC cell lines of CNE1 and CNE2 with different radiosensitivities were established. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to get a 546bp fragment (8578nt-9123nt) of ATM cDNA, containing the PI-3 kinase domain (8753-8815bp). Direct sequencing of RT-PCR product was applied to determine the mutations in the gene. The sequence of the 546bp fragment is identical to the sequence of ATM gene published in GenBank, that is, there are no any mutations on the fragment of ATM/PI3K we examined either in CNE1 or in CNE2. It indicates that there may be no correlations between the mutation of ATM/PI3K and the variation of radiosensitivity in NPC cell lines CNE1, CNE2.
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PMID:[Study on mutation of ATM/PI3K region in NPC cell lines with different radiosensitivity]. 1563 69

In eukaryotic cells, different RNA species are exported from the nucleus via specialized pathways. The mRNA export machinery is highly integrated with mRNA processing, and includes a different set of nuclear transport adaptors as well as other mRNA binding proteins, RNA helicases, and NPC-associated proteins. The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease, a widespread and neglected human disease which is endemic to Latin America. Gene expression in Trypanosoma has unique characteristics, such as constitutive polycistronic transcription of protein-encoding genes and mRNA processing by trans-splicing. In general, post-transcriptional events are the major points for regulation of gene expression in these parasites. However, the export pathway of mRNA from the nucleus is poorly understood. The present study investigated the function of TcSub2, which is a highly conserved protein ortholog to Sub2/ UAP56, a component of the Transcription/Export (TREX) multiprotein complex connecting transcription with mRNA export in yeast/human. Similar to its orthologs, TcSub2 is a nuclear protein, localized in dispersed foci all over the nuclei -except the fibrillar center of nucleolus- and at the interface between dense and non-dense chromatin areas, proposing the association of TcSub2 with transcription/processing sites. These findings were analyzed further by BrUTP incorporation assays and confirmed that TcSub2 is physically associated with active RNA polymerase II (RNA pol II), but not RNA polymerase I (RNA pol I) or Spliced Leader (SL) transcription, demonstrating participation particularly in nuclear mRNA metabolism in T. cruzi. The double knockout of the TcSub2 gene is lethal in T. cruzi, suggesting it has an essential function. Alternatively, RNA interference assays were performed in Trypanosoma brucei. It allowed demonstrating that besides being an essential protein, its knockdown causes mRNA accumulation in the nucleus and decrease of translation levels, reinforcing that Trypanosoma-Sub2 (Tryp-Sub2) is a component of mRNA transcription/export pathway in trypanosomes.
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PMID:An essential nuclear protein in trypanosomes is a component of mRNA transcription/export pathway. 2168 72

The first step of gene expression results in the production of mRNA ribonucleoparticles (mRNPs) that are exported to the cytoplasm via the NPC for translation into the cytoplasm. During this process, the mRNA molecule synthesized by RNA polymerase II (Pol II) undergoes extensive maturation, folding and packaging events that are intimately coupled to its synthesis. All these events take place in a chromatin context and it is therefore not surprising that a growing number of studies recently reported specific contributions of chromatin dynamics to various steps of mRNP biogenesis. In this extra view, we replace our recent findings highlighting the contribution of the yeast chromatin remodeling complex ISW1 to nuclear mRNA quality control in the context of the recent literature.
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PMID:Novel functions for chromatin dynamics in mRNA biogenesis beyond transcription. 2786 41