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)

Bovine aortic endothelial (BAE) cells spontaneously form structures in vitro that resemble capillary-like cords or tubes. This process is associated with changes in the expression of certain extracellular matrix proteins that include type I collagen. BAE cells exhibiting angiogenesis in vitro were transfected with plasmids containing either chloramphenicol acetyltransferase or human growth hormone genes directed by promoter sequences from the human alpha 1(I)-collagen gene. Immunostaining for chloramphenicol acetyltransferase demonstrated that collagen promoter activity was restricted to cells involved in the formation of endothelial cords. In comparison to transfected monolayers of BAE cells, the transcriptional activity of the alpha 1(I)-collagen promoter increased by 7-fold in cultures undergoing angiogenesis in vitro. The selective ability of angiogenic endothelium to utilize the alpha 1(I)-collagen promoter is consistent with previous studies showing high levels of alpha 1(I)-collagen mRNA in BAE cells actively engaged in the formation of tubes (Iruela-Arispe, L., Hasselaar, P., and Sage, H. (1991) Lab. Invest. 64, 174-186). We conclude that transcriptional activation of the alpha 1(I)-collagen gene is closely linked to the morphologic alterations in cellular phenotype that accompany the transition of quiescent endothelial monolayers to the angiogenic state.
J Biol Chem 1991 Sep 25
PMID:Transcriptional activity of the alpha 1(I)-collagen promoter is correlated with the formation of capillary-like structures by endothelial cells in vitro. 191 59

Previously we described a cell line OCI-LY3 derived from a patient with non-Hodgkin's lymphoma. The cell line produced interleukin-6 (IL-6) mRNA and protein and demonstrated an autocrine pattern of growth for IL-6. Southern blot analysis of the IL-6 gene did not reveal any rearrangement. To determine whether the production of IL-6 by OCI-LY3 was due to subtle changes in the promoter of IL-6 or due to the expression of trans-acting factors chloramphenicol acetyltransferase (CAT) reporter constructs containing from -1,180 to +13 to -112 to +13 of a normal IL-6 gene were electroporated into the cell line. When these constructs are transferred into unstimulated fibroblasts, no CAT activity is seen; however, CAT activity is induced when the cells are stimulated with either IL-1 alpha, lipopolysaccharide (LPS), or cyclic adenosine monophosphate (cAMP) analogues. When the cell line OCI-LY3 was transfected with these constructs, CAT activity was observed; it was not necessary to stimulate the cells with exogenous factors to observe this activity. No CAT activity was observed in a second lymphoma cell line, OCI-LY13.1, that does not produce IL-6. These results suggest that the constitutive production of IL-6 by the cell line OCI-LY3 is due to the presence of trans-acting factors that stimulate the expression of IL-6 and not due to a cis-acting mutation of the IL-6 promoter.
J Cell Physiol 1991 Sep
PMID:Regulation of interleukin-6 expression in the lymphoma cell line OCI-LY3. 191 71

In this study we cloned the 5' flanking sequence of the human c-yes gene and identified its promoter region. A 0.53 kilobase pair (kbp) fragment containing the 5' terminus of the c-yes gene showed strong promoter activity when placed upstream of the bacterial chloramphenicol acetyltransferase (CAT) gene and transfected into monkey CV-1 cells. By nuclease S1 mapping multiple transcriptional start sites were detected within the promoter region. Nucleotide sequence analysis revealed that the c-yes promoter region had high G + C contents (64%) and contained six GC box-like sequences (one at the 5' distal region and five in a cluster at the 5' proximal region), but not a TATA box. These features of the c-yes promoter region are similar to those of other protooncogenes, ras-family genes and c-raf-1, and some house-keeping genes. Deletion analysis suggested that the most downstream 0.21 kbp region is primarily important for the promoter activity. This 0.21 kbp region contains one major and another minor transcriptional start site. Five GC box-like sequences were located within this region, and four of them were shown to bind with purified Sp1 transcription factor. Furthermore, using the base-substituted mutants of the Sp1-binding sites, each GC box in the cluster (GC1 to GC4) was shown to affect the c-yes gene expression.
Oncogene 1991 Sep
PMID:Characterization of the promoter region of the c-yes proto-oncogene: the importance of the GC boxes on its promoter activity. 192 23

Purine nucleoside phosphorylase (PNP) is a ubiquitously expressed enzyme which contributes to the catabolism and recycling of nucleotides. To characterize the promoter region of the human PNP gene, the nucleotide sequence from a BamHI site located in the 5' untranslated region extending 2237 bp upstream to an XbaI site was determined. The transcriptional start site as determined by primer extension was 119 bp upstream of the coding sequence and consisted of a 5'-CA-3' dimer with A at +1. A TATA box was identified -24 to -29 bp upstream of the transcriptional start site. A CCAAT pentamer sequence in the inverted orientation was present at -51 to -55 bp and two GC rich regions were identified at -68 to -81 bp and -168 to -187 bp. Progressive 5' deletions of the 5' flanking region were fused to the chloramphenicol acetyltransferase (CAT) reporter gene and transient expression measured after transfection of murine NIH/3T3 fibroblasts. A 91 bp promoter (the shortest tested) provided CAT activity at 60% the level of a 216 bp promoter, possibly due to removal of the GC rich region between -168 and -187 bp. Longer promoters resulted in CAT expression at similar or lower levels than the 216 bp promoter indicating that this region contained all of the 5' flanking sequences affecting transcription from the PNP promoter.
Nucleic Acids Res 1991 Sep 25
PMID:Sequence and functional characterization of the human purine nucleoside phosphorylase promoter. 192 69

The rat beta-galactoside alpha 2,6-sialytransferase gene is differentially utilized by liver and kidney in the generation of mRNAs that predict substantially divergent polypeptides. In order to determine the biosynthetic relationship between these sialyltransferase mRNA isoforms, genomic sequences were isolated and analysed. Five exons that span at least 40 kb of DNA carry the coding information for the liver beta-galactoside alpha 2,6-sialyltransferase protein. An additional exon contains only sequences for the 5'-untranslated leader of the liver mRNA. In contrast, the predominant kidney mRNAs from this gene share only three coding exons that specify the carboxyl terminal 42% of the liver sialyltransferase protein sequence. In addition, these kidney mRNAs contain information from two other exons that comprise the 5' divergent region of these transcripts. Primer extension and S1 nuclease protection analysis demonstrate that the hepatic and kidney specific mRNAs are transcriptionally initiated at different sites within the sialyltransferase gene. While the hepatic sialyltransferase mRNAs are transcribed from the first exon, the kidney transcripts are initiated from a site within the third intron. Genomic regions upstream of both transcriptional initiation sites can regulate expression of the bacterial chloramphenicol acetyltransferase gene in transiently transfected L cells. Together, the data implicate multiple promoters as a principle mechanism in the generation of kidney and liver gene product diversity in sialyltransferase expression.
Glycobiology 1990 Sep
PMID:Rat beta-galactoside alpha 2,6-sialyltransferase genomic organization: alternate promoters direct the synthesis of liver and kidney transcripts. 198 83

Previous studies have located some twenty distinct sites within the 2.3 kb 5' regulatory domain of the sea urchin CyIIIa cytoskeletal actin gene, where there occur in vitro high-specificity interactions with nuclear DNA-binding proteins of the embryo. This gene is activated in late cleavage, exclusively in cells of the aboral ectoderm cell lineages. In this study, we investigate the functional importance in vivo of these sites of DNA-protein interaction. Sea urchin eggs were coinjected with a fusion gene construct in which the bacterial chloramphenicol acetyltransferase (CAT) reporter gene is under the control of the entire CyIIIa regulatory domain, together with molar excesses of one of ten nonoverlapping competitor subfragments of this domain, each of which contains one or a few specific site(s) of interaction. The exogenous excess binding sites competitively titrate the available regulatory factors away from the respective sites associated with the CyIIIa.CAT reporter gene. This provides a method for detecting in vivo sites within the regulatory domain that are required for normal levels of expression, without disturbing the structure of the regulatory domain. We thus identify five nonoverlapping regions of the regulatory DNA that apparently function as binding sites for positively acting transcriptional regulatory factors. Competition with a subfragment bearing an octamer site results in embryonic lethality. We find that three other sites display no quantitative competitive interference with CyIIIa.CAT expression, though as shown in the accompanying paper, two of these sites are required for control of spatial expression. We conclude that the complex CyIIIa regulatory domain must assess the state of many distinct and individually necessary interactions in order to properly regulate CyIIIa transcriptional activity in development.
Development 1990 Sep
PMID:Competitive titration in living sea urchin embryos of regulatory factors required for expression of the CyIIIa actin gene. 208 68

The CyIIIa.CAT fusion gene was injected into Strongylocentrotus purpuratus eggs, together with excess ligated competitor sequences representing subregions of the CyIIIa regulatory domain. In this construct, the chloramphenicol acetyltransferase (CAT) reporter gene is placed under the control of the 2300 nucleotide upstream regulatory domain of the lineage-specific CyIIIa cytoskeletal actin gene. CAT mRNA was detected by in situ hybridization in serial sections of pluteus stage embryos derived from the injected eggs. When carrier DNA lacking competitor CyIIIa fragments was coinjected with CyIIIa.CAT, CAT mRNA was observed exclusively in aboral ectoderm cells, i.e. the territory in which the CyIIIa gene itself is normally expressed (as also reported by us previously). The same result was obtained when five of seven different competitor subfragments bearing sites of DNA-protein interaction were coinjected. However, coinjection of excess quantities of either of two widely separated, nonhomologous fragments of the CyIIIa regulatory domain produced a dramatic ectopic expression of CAT mRNA in the recipient embryos. CAT mRNA was observed in gut, mesenchyme cells and oral ectoderm in these embryos. We conclude that these fragments contain regulatory sites that negatively control spatial expression of the CyIIIa gene.
Development 1990 Sep
PMID:Negative spatial regulation of the lineage specific CyIIIa actin gene in the sea urchin embryo. 208 69

The 5'-terminal region of the rat gene for the neuron-specific phosphoprotein, synapsin I, was isolated and sequenced. It comprises 1472 nucleotides (nt) of 5'-flanking sequence, 507 nt of the first exon, and 242 nt of the first intron. A single transcription start site was mapped by primer extension and S1 nuclease analysis. A sequence of 340 nt upstream from the transcription start site and the first exon are G+C-rich and enriched in CpG dinucleotides, resembling a CpG island. The 5'-flanking sequence lacks TATA and CAAT consensus elements but contains a consensus motif for the cAMP-responsive element. Furthermore, we notice two potential consensus motifs which are also found in corresponding positions in the genes for the nerve growth factor receptor and the 68-kDa neurofilament protein. The 5'-terminal region of the human synapsin I gene was also cloned and sequenced. A high degree of sequence conservation between rat and human is found in the upstream 340 nt that coincides precisely with the G+C-rich domain and includes the consensus elements, and throughout the first exon including the untranslated sequence. Sequence conservation is also observed further upstream and at the beginning of the first intron. In a transient chloramphenicol acetyltransferase expression assay, 5'-flanking sequences of the rat synapsin I gene function as strong promoters in neuroblastoma cells, but not in fibroblastoid cells. 225 nt of 5'-flanking sequence and 105 nt of 5'-untranslated sequence are sufficient for cell-type specific transcription in this assay.
J Biol Chem 1990 Sep 05
PMID:The 5'-flanking region of the synapsin I gene. A G+C-rich, TATA- and CAAT-less, phylogenetically conserved sequence with cell type-specific promoter function. 211 19

We report the identification and characterization of the cis-acting elements responsible for the expression of the rat cholecystokinin (CCK) gene. Deletion mutations were constructed by linking variable amounts of the 5'-flanking region of the CCK gene to the bacterial chloramphenicol acetyltransferase reporter gene. The transcriptional activity of the CCK promoter deletion constructs was measured by monitoring chloramphenicol acetyltransferase enzyme activity after transient transfections. It is shown that sequences within 102 base pairs of the cap site are required for the expression from this promoter. This region contains a sequence that is identical to the -296 element of the human c-fos gene and is homologous with the polyoma enhancer and the cAMP- and 12-O-tetradecanoylphorbol-13-acetate-responsive elements described for several genes. In addition, the -119 to -81 fragment of the CCK promoter contains a transcriptional enhancer that potentiates the transcription from the herpes simplex virus thymidine kinase promoter in a position- and orientation-independent manner. DNase I protection and gel retardation experiments indicated the ability of several trans-acting factors found in nuclear extracts to bind specifically to regions of the CCK promoter. In particular, two complexes formed adjacent to the CCK enhancer region. One complex, CCK-1a, formed with sequences 5' to the enhancer whereas the other complex, CCK-1b, formed with the sequences identified by DNase I footprinting, 3' to the enhancer. Oligonucleotide competition experiments indicated that these complexes are formed by the same transacting factor or factors with similar binding specificities.
J Biol Chem 1990 Sep 15
PMID:A transcriptional enhancer essential for the expression of the rat cholecystokinin gene contains a sequence identical to the -296 element of the human c-fos gene. 211 25

The cat-86 gene specifies chloramphenicol acetyltransferase (CAT). The cat-86 start codon is UUG, although related genes have AUG as the start codon. Changing the start codon to AUG increased expression of cat-86 by 36% in Bacillus subtilis. Changing the start codon to GUG and CUG decreased expression to 65% and 30%, respectively, of the level obtained when AUG was the start codon. CUG has not been previously shown to function as a start codon in B. subtilis. N-terminal sequencing of purified CAT protein specified by the CUG mutant, revealed that CUG was indeed the start codon and specified methionine. The gene xylE, which specifies catechol 2,3-dioxygenase, has AUG as its start codon. Changing the start codon for xylE to CUG decreased expression by 98%. However, when the ribosome-binding site sequence for xylE was optimized and the spacing between it and the start codon was increased to 8 nucleotides, xylE activity increased to 13% of the activity observed for AUG. CUG did not function efficiently as a start codon for cat-86 in Escherichia coli. These data suggest conditions under which CUG can function, with modest efficiency, as a start codon in B. subtilis.
Gene 1990 Sep 28
PMID:CUG as a mutant start codon for cat-86 and xylE in Bacillus subtilis. 212 17


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