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)

The inclusion of the alcohol dehydrogenase 1-S(Adh 1-S) intron 1 in the transcription unit of maize gene constructs has been shown to increase gene expression in cultured maize cells. We have extended these studies with Adh1-S intron 1 using the firefly luciferase, Escherichia coli beta-glucuronidase and chloramphenicol acetyltransferase reporter genes adjoined to different plant promoters and find enhancement of transient gene expression in all cases but one. We also show that the enhancement phenomenon can be mediated by the third intron of the maize actin gene. In all cases tested, the inclusion of an intron results in increased levels of steady-state RNA. The degree of enhancement depends on the exon sequences flanking the intron; flanking exons also influence the efficiency of intron splicing. Unexpectedly, unspliced RNAs accumulate during the transient assay.
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PMID:Intron enhancement of gene expression and the splicing efficiency of introns in maize cells. 200 94

Expression of the maize alcohol dehydrogenase 1 (Adh1) gene is transcriptionally regulated under conditions of anaerobic stress. DNA sequences required for the expression of Adh1 have been identified by a functional analysis of in vitro constructed hybrid genes consisting of the Adh1 promoter fused to the chloramphenicol acetyltransferase coding region. A series of 5' deletions, 3' deletions, hybrid promoters, and linker scanning mutants of the Adh-CAT hybrid gene were introduced into maize protoplasts by electroporation and assayed for chloramphenicol acetyltransferase activity after incubation of the protoplasts under different oxygen tensions. The results indicate that a 40-base-pair DNA sequence within the Adh1 promoter is required for anaerobically regulated expression of the hybrid gene. Clustered point mutations in this sequence show that it is composed of two essential regions, each approximately 15 base pairs, separated by a 10-base-pair DNA sequence that does not appear to be important for anaerobic expression. Attachment of this 40-base-pair element to an unrelated promoter shows that this DNA sequence is both necessary and sufficient for induction of gene expression by low oxygen stress.
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PMID:DNA sequences required for anaerobic expression of the maize alcohol dehydrogenase 1 gene. 1657 16

This report describes a process for delivering foreign genes into maize cells that does not require the removal of cell walls and is capable of delivering DNA into embryogenic and nonembryogenic tissues. Plasmid harboring a chimeric chloramphenicol acetyltransferase (CAT) gene was adsorbed to the surface of microscopic tungsten particles (microprojectiles). These microprojectiles were then accelerated to velocities sufficient for penetrating the cell walls and membranes of maize cells in suspension culture. High levels of CAT activity were consistently observed after bombardment of cell cultures of the cultivar Black Mexican Sweet, which were comparable to CAT levels observed after electroporation of protoplasts. Measurable increases in CAT levels were also observed in two embryogenic cell lines after bombardment. Gene expression was observed only when an intron from the alcohol dehydrogenase 1 gene of maize was ligated between the 35S promoter and the CAT coding region. CAT activity was detected in cell cultures bombarded with microprojectiles with an average diameter of 1.2 mum, but not after bombardment with microprojectiles 0.6 or 2.4 mum in diameter. Bombarding the same sample several times was found to markedly enhance CAT activity. These results demonstrate that the particle bombardment process can be used to deliver foreign DNA into intact cells of maize. Because this process circumvents the difficulties associated with regenerating whole plants from protoplasts, the particle bombardment process may provide significant advantages over existing DNA delivery methods for the production of transgenic maize plants. In addition, the process should be of value for studying transient and stable gene expression within intact cells and tissues.
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PMID:Transfer of foreign genes into intact maize cells with high-velocity microprojectiles. 1659 42