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)

Trienoic fatty acids (TAs), the major constituents in plant membrane lipids, play essential roles in stress signalling as precursors of the phytohormone jasmonic acid (JA). Arabidopsis FAD7 encodes a plastidial omega-3 fatty acid desaturase, which catalyses the production of TAs. In coordination with other JA-biosynthetic genes, expression of FAD7 is induced locally by wounding. This provides a feedforward mechanism for the rapid and sustainable accumulation of JA. To identify molecular components involved in this mechanism, a transgenic Arabidopsis line carrying the FAD7 promoter (pFAD7) fused to the firefly luciferase gene (LUC) was constructed. Reciprocal crossing experiments revealed that the induction of FAD7 expression depends largely on JA biosynthesis and the SCF(COI1)-mediated signalling mechanism, whereas JA alone is insufficient for its maximal induction. Full induction required synergistic interactions between JA-dependent and -independent wound signalling mechanisms. A genetic screen for aberrant pFAD7::LUC expression yielded a recessive mutant showing enhanced wound-induced LUC bioluminescence. The mutation was associated with the cpl1 locus encoding an RNA polymerase II C-terminal domain (CTD) phosphatase, and conferred wound hyper-responsiveness on the promoters of several JA-biosynthetic genes. The picture of signalling mechanisms underlying the wound-regulated FAD7 expression, and potential roles of CPL proteins as attenuators of wound-induced JA biosynthesis, are discussed.
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PMID:CTD phosphatases in the attenuation of wound-induced transcription of jasmonic acid biosynthetic genes in Arabidopsis. 1876 23

The direct negative impact of the transcriptional activity of one component on the second one in cis is referred to as transcriptional interference (TI). U6 is a type III RNA polymerase III promoter commonly used for driving small hairpin RNA (shRNA) expression in vector-based RNAi. In the design and construction of viral vectors, multiple transcription units may be arranged in close proximity in a space-limited vector. Determining if U6 promoter activity can be affected by TI is critical for the expression of target shRNA in gene therapy or loss-of-function studies. In this research, we designed and implemented a modified retroviral system where shRNA and exogenous gene expressions were driven by two independent transcriptional units. We arranged U6 promoter driving shRNA expression and UbiC promoter in two promoter arrangements. In primary macrophages, we found U6 promoter activity was inhibited by UbiC promoter when in the divergent arrangement but not in tandem. In contrast, PKG promoter had no such negative impact. Instead of enhancing U6 promoter activity, CMV enhancer had significant negative impact on U6 promoter activity in the presence of UbiC promoter. Our results indicate that U6 promoter activity can be affected by TI in a proximal promoter-specific and arrangement-dependent manner.
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PMID:Regulation of U6 promoter activity by transcriptional interference in viral vector-based RNAi. 2097 Jul 45

Arabidopsis RNA polymerase II (RNAPII) C-terminal domain (CTD) phosphatases regulate stress-responsive gene expression and plant development via the dephosphorylation of serine (Ser) residues of the CTD. Some of these phosphatases (CTD phosphatase-like 1 (CPL1) to CPL3) negatively regulate ABA and stress responses. Here, we isolated AtCPL5, a cDNA encoding a protein containing two CTD phosphatase domains (CPDs). To characterize AtCPL5, we analyzed the gene expression patterns and subcellular protein localization, investigated various phenotypes of AtCPL5-overexpressors and knockout mutants involved in ABA and drought responses, performed microarray and RNA hybridization analyses using AtCPL5-overexpressors, and assessed the CTD phosphatase activities of the purified AtCPL5 and each CPD of the protein. Transcripts of the nucleus-localized AtCPL5 were induced by ABA and drought. AtCPL5-overexpressors exhibited ABA-hypersensitive phenotypes (increased inhibition of seed germination, seedling growth, and stomatal aperture), lower transpiration rates upon dehydration, and enhanced drought tolerance, while the knockout mutants showed weak ABA hyposensitivity. AtCPL5 overexpression changed the expression of numerous genes, including those involved in ABA-mediated responses. In contrast to Ser-5-specific phosphatase activity of the negative stress response regulators, purified AtCPL5 and each CPD of the protein specifically dephosphorylated Ser-2 in RNAPII CTD. We conclude that AtCPL5 is a unique CPL family protein that positively regulates ABA-mediated development and drought responses in Arabidopsis.
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PMID:AtCPL5, a novel Ser-2-specific RNA polymerase II C-terminal domain phosphatase, positively regulates ABA and drought responses in Arabidopsis. 2123 36