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)

Pancreatic amylase, chymotrypsin B, and trypsin I genes are specifically expressed in the exocrine pancreas. The 5'-flanking regions of these genes direct preferential expression of a linked reporter function (chloramphenicol acetyltransferase) in the pancreatic exocrine cell line AR4-2J. The sequences upstream of the amylase and chymotrypsin genes that are required for this cell specific activity possess the characteristics of transcriptional enhancers. We have mapped the regions responsible for enhancer activity by deletion analysis. Modification of specific nucleotide sequences within these regions can alter or eliminate enhancer function. Comparison of the 5'-flanking regions of nine genes expressed in the exocrine pancreas identifies a family of short related sequences. These sequences are located within the enhancer regions that we have mapped and may play a role in the regulation of the expression of pancreatic exocrine-specific genes.
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PMID:Cell-specific enhancers in the rat exocrine pancreas. 242 7

Eight eukaryotic promoters have been tested for their activity in vivo in Escherichia coli. The rat beta-actin, rat amylase, rat chymotrypsin B, mouse metallothionein I, rat insulin I, human insulin, Rous sarcoma virus long terminal repeat (RSV LTR) and hepatitis B viral precore promoter activities were measured by using the bacterial chloramphenicol acetyltransferase coding sequences as the reporter function and by primer extension RNA analysis. All eight promoter-chloramphenicol acetyltransferase constructs produce chloramphenicol acetyltransferase activity with the following relative strengths: RSV LTR greater than rat beta-actin greater than rat insulin I greater than rat amylase greater than hepatitis B virus precore greater than human insulin greater than rat chymotrypsin B greater than mouse metallothionein I. A primer extension analysis indicates that transcription from the RSV LTR, rat insulin I, and rat beta-actin promoters initiates at the sites expected for eukaryotic rather than prokaryotic promoters. Thus the site of initiation is determined by the DNA sequence rather than by the RNA polymerase.
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PMID:Eukaryotic promoters drive gene expression in Escherichia coli. 268 Nov 82

Treatment of the rat pancreatic acinar cell line AR4-2J with the calcium ionophore A23187 selectively increases, within a few hours, the steady-state level of trypsin mRNA. Addition of the tumor-promoting phorbol ester phorbol 12-myristate 13-acetate potentiates the calcium-induced increase. The mRNA level of the other tested exocrine pancreatic genes decreases. These results were confirmed by DNA transfection experiments, using the 5' flanking region of the trypsin and chymotrypsin genes linked to the coding sequence of the chloramphenicol acetyltransferase (CAT) gene. In calcium-induced cells transfected with the trypsin constructs, an increase in CAT activity was observed, whereas the chymotrypsin constructs revealed a decreased CAT activity. Glucose starvation of AR4-2J cells similarly elicited a selective increase in trypsin mRNA. This selective regulation of trypsin may reflect its role as the key activator of the other zymogen species.
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PMID:Selective regulation of trypsin gene expression by calcium and by glucose starvation in a rat exocrine pancreas cell line. 308 79

DNA sequences containing the 5'-flanking regions of the insulin and chymotrypsin genes were linked to the coding sequence of the chloramphenicol acetyltransferase (CAT) gene. The insulin gene recombinant elicits preferential expression of CAT activity when introduced into cells producing insulin; similarly, the chymotrypsin gene recombinant elicits preferential expression in chymotrypsin-producing cells. Sequences located upstream of previously defined transcriptional control elements are essential for efficient expression in both cases.
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PMID:Cell-specific expression controlled by the 5'-flanking region of insulin and chymotrypsin genes. 635