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 isolated and sequenced a Drosophila genomic DNA sequence that encodes the entire coding region of the laminin B2 chain. The 11,464-bp genomic sequence contains a 2.1-kb of 5'-flanking DNA, ten exons, nine introns, and the 3'-flanking region. The first exon encodes a 5' untranslated region; the ATG translational start codon is in exon 2. The entire translated region is within a 8.3-kb Eco RI fragment. The Drosophila laminin B2 gene differs substantially in size and exon pattern from those of the human B1 and B2 genes. However, as in the case of the human B1 gene, the overall exon pattern of the Drosophila B2 gene does not correlate well with the highly conserved structural domains and internal repeats of the B2 polypeptide chain. Unlike the human and mouse B1 and B2 genes, the 2.1-kb 5'-flanking region of the Drosophila B2 gene contains a TATA box and two CAAT boxes. Other potential transcriptional regulatory sequences include two reverse complementary cAMP response element sequences; two sequences that are homologous to the retinoic acid response element motifs of the mouse B1 gene; and sequences homologous to the binding sites for transcription factors dFRA and dJRA, zeste, and possibly GAGA. When transfected into Drosophila SL-2 cells, pCAT plasmid containing 2,090 bp of 5'-flanking region shows a 3.0- to 3.5-fold increase in chloramphenicol acetyltransferase activity after induction with retinoic acid and/or 8-bromo-cAMP. These results suggest that this 5'-flanking promoter region may contain DNA sequences that can regulate the expression of the laminin B2 gene.
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PMID:Structure of the Drosophila gene for the laminin B2 chain. 184 May 13

We previously isolated cDNA clones coding for the entire murine laminin B2 chain. In this report, we have screened a mouse genomic library with a 5' portion of the laminin B2 chain cDNA and isolated two genomic clones which contain the first and second exons. The transcription initiation site was determined by primer extension and S1 nuclease mapping. Exon 1 contained 641 bp (base pairs) including 229 bp of 5'-untranslated segment, sequences coding for the signal peptide and the N-terminal portion of the protein, while exon 2 contained 305 bp. Nucleotide sequencing of 830 bp of the 5'-flanking region of the gene showed several interesting features including the presence of 9 "GC" boxes, a stretch of 9 nearly identical repeats of 11 nucleotides between -200 and -450, and a sequence which is similar to the cAMP consensus sequence. There was no TATA box or CAAT box. A recombinant plasmid containing the 830 bp promoter segment coupled to the chloramphenicol acetyltransferase gene was constructed and transfected into various cells. Differentiated F9 cells transfected with this construct showed twice as much chloramphenicol acetyltransferase activity as the undifferentiated cells. The 830-bp B2 laminin promoter was also active in NIH-3T3 cells which produce little laminin, but was not active in human HT-1080 cells. These results indicate that this structurally unique promoter contains DNA sequences that help regulate the gene during differentiation.
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PMID:The laminin B2 chain promoter contains unique repeat sequences and is active in transient transfection. 283 21

We have isolated and sequenced a Drosophila genomic DNA that encodes the entire coding region of the laminin B1 chain. The genomic DNA sequenced spans 11,787 bp, including a 1.1-kb 5'-flanking region, 5 exons, 4 introns, and a 1.4-kb 3'-flanking region. The open reading frame is within the two largest exons, the exons 3 and 4, while the first two and the last exons are much smaller and are untranslated. The structure of the Drosophila laminin B1 gene is similar to the Drosophila laminin B2 gene. Their exon-intron lengths and Eco RI, Pst I restriction maps are quite conserved. Both of their open reading frames are very compact, and their first introns are much larger than all of the rest of the introns. These results are consistent with the suggestion that the B1 and B2 genes could be derived from an ancestral gene. The similarity of the proximal 5'-flanking regions of the Drosophila B1 and B2 genes is 46.6%. Also, similar sequences of transcriptional regulatory elements, even though not site conserved, are found in both proximal 5'-flanking regions of the B1 and B2 genes. When transfected into Drosophila SL-2 cells, pCAT plasmid containing 1,048 bp of 5'-flanking region shows a strong expression of chloramphenicol acetyltransferase (CAT) activity. The deletion clones that contain sequences between nucleotides -462 to +150, and -282 to +150 all show strong CAT activity. These results suggest that this 5'-flanking promoter region may contain DNA sequences that can promote the expression of the laminin B1 gene.
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PMID:Analysis of the Drosophila gene for the laminin B1 chain. 839 15