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)

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.
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PMID:Characterization of the promoter region of the c-yes proto-oncogene: the importance of the GC boxes on its promoter activity. 192 23

Transfection of primary rat fetal brown adipocytes with constructs of SV40 large T antigen, alone and together with lys12-mutated H-ras gene, gave permanent cell lines showing an immortalized or transformed phenotype, respectively, all of them selected by the expression of the uncoupling protein (UCP), a tissue-specific marker. Primary brown adipocytes and immortalized cell lines respond to insulin-like growth factor I (IGF-I) by increasing their lipid content and the mRNA expression of both the adipogenic marker fatty acid synthase (FAS) and the thermogenic marker UCP. IGF-I-induced differentiation-related gene expression at 24 h in both primary and immortalized brown adipocytes was mediated by an increase in p21ras.GTP active protein content. Transformed cell lines overexpressing exogenous p21ras (mainly in its ras.GTP active form) constitutively showed a higher lipid content and a higher FAS and UCP mRNA expression compared to primary and immortalized cells. These transformed cells were IGF-I independent with respect to their studied differentiation-related parameters. Additionally, transient transfection of primary brown adipocytes with the transforming ras gene induced UCP and FAS mRNA expression as well as cotransactivated UCP-chloramphenicol acetyltransferase fusion gene. Moreover, IGF-I transactivation of UCP promoter was partially precluded by cotransfection with the dominant-negative ras gene. Our results strongly suggest that IGF-I/p21ras induces adipogenic- and thermogenic-related gene expression in brown adipocytes.
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PMID:p21ras induced differentiation-related gene expression in fetal brown adipocyte primary cells and cell lines. 887 5