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)

Previously we have shown that bovine vascular smooth muscle cells (SMCs) express c-myb mRNA (Reilly, C. F., Kindy, M. S., Brown, K. E., Rosenberg, R. D., and Sonenshein, G. E. (1989) J. Biol. Chem. 264, 6990-6995). Here we have characterized changes in the low level of c-myb mRNA expressed in quiescent serum-deprived subconfluent SMCs upon entry into the cell cycle. After serum stimulation, levels of c-myb mRNA increased 3-4-fold during late G1 and remained at this level during S phase. A 1.5-kilobase partial c-myb cDNA clone, isolated from a bovine SMC library, was partially sequenced and found to be 89 and 85% homologous to the human and murine c-myb genes, respectively. Using bovine and murine c-myb clones, no change in the rate of c-myb gene transcription or mRNA stability was detected during the cell cycle. Thus, the regulation of changes in c-myb mRNA levels in SMCs appears distinct from mechanisms seen in hematopoietic or fibroblastic cells. Vectors containing myb binding sites linked to the thymidine kinase promoter and the chloramphenicol acetyltransferase reporter gene were transiently transfected into SMC cultures. KHK-CAT-dAX, which contains nine concatenated myb binding sites, exhibited 7-fold more activity than the parental dAX-TK-CAT vector in exponentially growing SMCs. The levels of chloramphenicol acetyltransferase activity in exponentially growing cells were approximately 2-fold higher than in cells that had been serum deprived for 24 h and were entering quiescence. Thus SMCs produce a functional c-myb protein that can activate transcription from a heterologous promoter. Furthermore, introduction of antisense c-myb oligonucleotides to quiescent serum-deprived SMC cultures severely inhibited entry of cells into S phase upon serum addition. Thus, expression of the c-myb oncogene plays an important role in cell cycle progression of SMCs.
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PMID:Expression of the c-myb proto-oncogene in bovine vascular smooth muscle cells. 153 45

A 1,937 bp PstI-HindIII fragment containing the ipaR locus was cloned from the large invasion plasmid of Shigella dysenteriae CG097, and its nucleotide sequence was completely determined. The IpaR protein (35 kDa, calculated from the DNA sequence) was synthesized in Escherichia coli chi 1411 minicells containing the 1,937-bp PstI-HindIII fragment. To determine the regulatory role of ipaR for ipa genes, we applied genetic complementation experiments using chloramphenicol acetyltransferase (CAT) as reporter. Analyses of CAT activity of the recombinant plasmids containing the 5' flanking sequences of the 24-kDa-protein gene and the ippI, ipaB, ipaC, and ipaD genes defined strong promoters upstream of the 24-kDa-protein gene and ipaD gene, weak promoters upstream of the ippI and ipaB genes, and the absence of any promoter activity for the ipaC gene. Complementation analyses showed that the CAT activity only under direction of the ippI promoter region increased 1.8-fold in the presence of IpaR protein. On the basis of our data, we suggest that an operon comprising ippI, ipaB, and ipaC is positively regulated by IpaR protein which has a trans effect on a DNA sequence upstream of the ippI promoter.
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PMID:Nucleotide sequence and transcriptional regulation of a positive regulatory gene of Shigella dysenteriae. 154 32

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

Characterization of the human insulin-like growth factor binding protein-1 (IGFBP-1) promoter was initiated to facilitate study of developmental and hormonal factors regulating IGFBP-1 production. The region immediately 5' to the IGFBP-1 mRNA capsite is typical of a eukaryotic promoter, with a TATA sequence beginning 28 base pairs (bp) and a CCAAT promoter element beginning 72 bp upstream from this capsite. A 1.3-kilobase insert containing the IGFBP-1 capsite and 1205 bp of this putative IGFBP-1 promoter region directs expression of the reporter gene chloramphenicol acetyltransferase (CAT) in an orientation-specific manner in transfected HEP G2 cells, and the capsite identified for the CAT mRNA is identical to that identified for native IGFBP-1 mRNA. These observations suggest that the 1.3-kilobase insert contains the IGFBP-1 promoter. This promoter was further characterized by deletion analysis, site-directed mutagenesis, gel mobility shift assays, and DNaseI protection assays. These studies identify the CCAAT box region as the major cis element involved in basal IGFBP-1 promoter activity in HEP G2 cells, demonstrate that increased basal promoter activity is associated with the binding of at least one HEP G2 nuclear factor to the CCAAT box region, and indicate that the DNA binding factor(s) responsible for increased basal promoter activity is related to liver factor B1. These observations suggest that liver B1 is the major trans-acting factor stimulating basal IGFBP-1 promoter activity in HEP G2 cells.
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PMID:The promoter of the human gene for insulin-like growth factor binding protein-1. Basal promoter activity in HEP G2 cells depends upon liver factor B1. 170 Nov 75

The cis-acting regulatory elements of the osteonectin gene have been studied using a chloramphenicol acetyltransferase (CAT) promoter assay in osteonectin-expressing and nonexpressing cultured cells. When various stretches of the promoter were transiently transfected into fetal bovine bone cells, a positive element was detected in the DNA located between bases -504 and 11 (1 being the start of transcription) and a negative element between bases -900 and -504. The positive element of the promoter also conferred preferential expression of the gene, showing more activity in cells with higher levels of osteonectin mRNA expression. A 1.2 kb fragment of intron 1 displayed a negative effect on CAT expression when inserted 5' to the promoter. An additional regulatory element was found in DNA encoding exon 1, which significantly influenced expression of the gene in fetal bovine bone cells. Gel shift analysis using positive genomic elements located 5' to the start of transcription indicated that one of the nuclear proteins that interacts with the osteonectin promoter may be related to the transcription factor AP2.
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PMID:Expression of the osteonectin gene potentially controlled by multiple cis- and trans-acting factors in cultured bone cells. 179 60

The cyclic nucleotide phosphodiesterase (phosphodiesterase) plays essential roles throughout the development of Dictyostelium discoideum. It is crucial to cellular aggregation and to postaggregation morphogenesis. The phosphodiesterase gene is transcribed into three mRNAs, containing the same coding sequence connected to different 5' untranslated sequences, that accumulate at different times during the life cycle. A 1.9-kilobase (kb) mRNA is specific for growth, a 2.4-kb mRNA is specific for aggregation, and a 2.2-kb mRNA is specific for late development and is only expressed in prestalk cells. Hybridization of RNA isolated from cells at various stages of development with different upstream regions of the gene indicated separate promoters for each of the three mRNAs. The existence of specific promoters was confirmed by fusing the three putative promoter regions to the chloramphenicol acetyltransferase reporter gene, and the analysis of transformants containing these constructs. The three promoters are scattered within a 4.1-kilobase pair (kbp) region upstream of the initiation codon. The late promoter is proximal to the coding sequence, the growth-specific promoter has an initiation site that is 1.9 kbp upstream of the ATG codon, and the aggregation-specific promoter has an initiation site 3 kbp upstream.
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PMID:The cyclic nucleotide phosphodiesterase gene of Dictyostelium discoideum contains three promoters specific for growth, aggregation, and late development. 215 67

Human papillomavirus type 8 (HPV-8) is one aetiological agent of macular and flat wart-like lesions in patients with epidermodysplasia verruciformis and appears to be closely linked to skin carcinogenesis. A 1.2 kb region of the genome, which was previously shown to contain a viral E2-dependent enhancer, was progressively shortened from both ends with Bal 31. The resulting fragments were tested for their ability to stimulate chloramphenicol acetyltransferase (CAT) expression from the simian virus 40 (SV 40) promoter. This analysis showed a complex interaction between cis-active, positive and negative control elements located throughout the non-coding region and the flanking reading frames. Two separate positively acting sequences significantly stimulated expression only in cooperation with a third region, which led to 12-fold, E2-dependent enhancement on its own. A major negative element was not only active in the context of HPV-8 sequences, but also down-regulated SV40 enhancer-promoter-driven CAT expression when cloned downstream of the transcription unit. It acted at the transcriptional levels as shown by RNase protection assays and can therefore be regarded as a cis-acting silencer of transcription.
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PMID:Human papillomavirus type 8 contains cis-active positive and negative transcriptional control sequences. 217 59

A 1.2-kilobase pair fragment of the 5' upstream region of a potato wound-inducible gene (wun1) was fused to different marker genes (wun1-CAT, wun1-NPTII). Stable integration of a wun1-CAT chimeric gene into the tobacco genome led to a high wound-inducible chloramphenicol acetyltransferase activity in leaves. Transient expression experiments in potato protoplasts showed that wun1 carries a strong promoter sequence similar in strength to the 35S promoter. The same intensity of expression was also observed using wun1 constructs in transient experiments with rice protoplasts. wun1 mRNA was shown to accumulate to high levels in potato leaves collapsing as a result of infection with the phytopathogen Phytophthora infestans. The wun1 product might, therefore, play a role in a general physiological reaction to stress correlated with cell death.
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PMID:5' upstream sequences from the wun1 gene are responsible for gene activation by wounding in transgenic plants. 253 62

A 1-kilobase DNA fragment containing the promoter of the bovine prolactin gene was fused to the chloramphenicol acetyltransferase gene and the activity of the promoter was assayed by transfection of the fusion gene into COS-1, HeLa, and GH3 cells. Transcription of the chloramphenicol acetyltransferase gene driven by the prolactin promoter was detected only in GH3 cells, a rat pituitary tumor cell line. Epidermal growth factor and thyroid releasing hormone produced a stimulation of transcription, and the synthetic glucocorticoid hormone dexamethasone effected an inhibition of transcription from the prolactin promoter. None of these factors significantly affected transcription of the chloramphenicol acetyltransferase gene fused to the Rous sarcoma virus promoter. Deletion of all but 250 base pairs of bovine prolactin 5'-flanking DNA had no effect, indicating that the signals sufficient for both stimulation and inhibition of transcription reside in close proximity to the promoter.
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PMID:Hormonal regulation of the bovine prolactin promoter in rat pituitary tumor cells. 299 68

We cloned and compared the sequence of a rearranged human T cell receptor (TCR) V alpha J alpha gene and its germline counterparts. The only difference in the coding region sequence was confined to the joining region where three nucleotides, TTG, unaccountable by either V alpha or J alpha sequence, were present. By nuclease S1 mapping we identified the mRNA start of the alpha chain 70 nucleotides upstream from the initiator ATG. A 600 bp fragment containing the sequences upstream to the ATG drives the expression of the bacterial chloramphenicol acetyltransferase (CAT) gene. This promoter activity is T cell specific since it can be demonstrated in human T cells but not in B cells or HeLa cells. A 1.1 kb BamHI- HindIII fragment located 5' to the first exon of the C alpha gene was found to enhance transcription from either the heterologous SV40 promoter or the homologous TCR alpha chain promoter. This enhancement activity was independent of the location of the fragment with respect to CAT and was specific to lymphoid cells (either T or B cells) but cannot be demonstrated in HeLa cells.
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PMID:Promoter and enhancer elements in the rearranged alpha chain gene of the human T cell receptor. 350 68


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