Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have cloned a genomic fragment containing the promoter region of the rat protein phosphatase 2A alpha gene (PP-2A alpha). A 1.6 kb fragment of the 5' flanking region was sequenced. Three major transcriptional initiation sites were identified by the primer extension method using rat liver mRNA and found to be located 225, 222 and 220 bases upstream of the translational initiation site, respectively. Bacterial chloramphenicol acetyltransferase (CAT) assay revealed that a 503 bp SmaI fragment containing the transcriptional initiation sites had promoter activity, which was stronger than that of the SV40 early promoter on the pSV2CAT plasmid when introduced into NIH3T3 cells. Deletion of a 119 bp SacII fragment decreased its promoter activity considerably. The promoter region has an extremely high GC content and does not contain either a 'TATA box' or a 'CAAT box' suggesting that this promoter can be classified as that of a 'house keeping' gene, although there is only one typical GC-box (GGGCGG) immediately preceding the transcriptional initiation sites. There is a 10 base pair palindrome, 5'-GTGACGTCAC-3', 26 base pairs upstream of the +1 transcriptional initiation site, which is highly conserved in many other genes, whose expression is regulated by cAMP. The promoter activity was shown to be increased by forskolin treatment (10 microM) in NIH3T3 cells.
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PMID:Identification of the promoter region of the rat protein phosphatase 2A alpha gene. 165 Feb 51

The alpha and beta isoforms of the human protein phosphatase 2A catalytic subunit are encoded by distinct genes whose expression appears to be differentially regulated. To obtain a better understanding of the mechanism(s) that regulate(s) the expression of these two transcripts, we have cloned the genes encoding both isoforms. Both genes (each approximately 30 kbp) are composed of seven exons and six introns which intervene at identical locations, suggesting that they were derived from a common ancestral gene. However, the 5' upstream regions as well as the regions encoding the 5' and 3' untranslated sequences of each mRNA are different. The promoters of both genes are very G+C rich and lack the TATA and CCAAT sequences typical of many housekeeping genes. The C alpha gene contains several potential Sp1 binding sites and a potential cAMP-responsive element. Northern analysis using RNAs isolated from several different human cell lines showed that the steady-state C alpha mRNA was, in general, more abundant than the C beta mRNA. To determine whether the promoters regulate the differential C alpha and C beta RNA expression, they were fused to the reporter gene chloramphenicol acetyltransferase and transiently expressed in HeLa cells. Expression from the C alpha promoter was 7-10 times stronger than that from the C beta promoter, which paralleled the endogenous C alpha and C beta mRNA levels in HeLa cells. These data suggest that the steady-state levels of the C alpha and C beta mRNAs, are due, at least in part, to different promoter activities.
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PMID:Structure and transcriptional regulation of protein phosphatase 2A catalytic subunit genes. 184 93

The effects of okadaic acid (OA), a potent and specific inhibitor of serine/threonine phosphatases 2A and 1, on the transient expression of a human hsp 70 promoter-linked chloramphenicol acetyltransferase gene transfected into N-18 mouse neuroblastoma cells were determined. Assays of reporter gene activity showed that nanomolar concentrations of OA markedly potentiated the heat-induced (but not the basal) expression of pHBCAT, a full-length hsp 70 promoter-driven chloramphenicol acetyltransferase gene construct. This effect of OA was dose-dependent and promoter-specific and appeared to be attributable to inhibition of protein phosphatase 2A as opposed to protein phosphatase 1. The ability of OA to potentiate the heat-induced expression of pHBCAT appeared to be a feature common to several different cell types examined. We propose that the heat-induced transcriptional activation of heat shock genes is associated with the phosphorylation of component(s) of the transcription complex and that OA enhances this phosphorylation, thereby potentiating the heat-induced hsp 70 promoter activity.
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PMID:Okadaic acid markedly potentiates the heat-induced hsp 70 promoter activity. 838 Apr 12