Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.13.12.7 (firefly luciferase)
 2,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pyruvate carboxylase (EC 6.4.1.1) is a biotin-containing enzyme that plays an important role in gluconeogenesis and lipogenesis. Here we report the structural organization of the rat pyruvate carboxylase gene, which spans over 40 kilobases and is composed of 19 coding exons and 4 5'-untranslated region exons. From this data, it is clear that alternative splicing of the primary transcripts from two promoters is responsible for the occurrence of the multiple mRNA species previously reported (Jitrapakdee, S., Walker, M. E., and Wallace, J. C. (1996) Biochem. Biophys. Res. Commun. 223, 695-700). The proximal promoter, which is active in gluconeogenic and lipogenic tissues, contains no TATA or CAAT boxes but includes a sequence that is typical of a housekeeping initiator protein 1 box while the distal promoter contains three CAAT boxes and multiple Sp1 binding sites. Several potential transcription factor binding sites are found in both promoters. A series of 5'-nested deletion constructs of both promoters were fused to a firefly luciferase reporter plasmid and transiently expressed in COS-1 cells. The results show that the 153 and 187 base pairs, preceding the transcription start sites of the proximal and distal promoters, respectively, are required for basal transcription. Insulin selectively inhibits the expression of the proximal promoter-luciferase reporter gene by 50% but not the distal promoter in COS-1 cells, suggesting the presence of an insulin-responsive element in the proximal promoter. A half-maximal effect was found at approximately 1 nM insulin.
 ...
PMID:The rat pyruvate carboxylase gene structure. Alternate promoters generate multiple transcripts with the 5'-end heterogeneity. 925 65

Pyruvate carboxylase (PC) catalyzes a pivotal reaction in gluconeogenesis and lipid metabolism in liver. In bovine the PC gene is expressed as six 5' untranslated region (UTR) mRNA variants. The objectives for this study were to clone and sequence the bovine PC gene, determine the intron and exon organization and identify PC promoter region(s). Oligonucleotide sequences that corresponded to the 5' UTR mRNA variants and coding sequence of bovine PC were used to isolate 2 clones from the RPCI-42 bovine bacterial artificial chromosome (BAC) library. Sequencing data confirmed the presence of regions for the 5' UTR for bovine PC mRNA. The exon arrangement from 5' to 3' is 48 (exon I), 41 (exon II), 178 (exon IIIA and IIIB), and 185 (exon IV) bp. Three promoter regions, P3, P2, and P1, adjacent to exon I, II, and IIIA, respectively, were identified based on computer analysis of sequence data. Putative promoters were cloned into a firefly luciferase vector and transiently transfected into H4IIE rat hepatoma cells. All PC promoters demonstrated luciferase activity comparable with the minimal promoter luciferase vector and higher than the promoterless luciferase vector. In addition, PC promoter 1 exhibited greater luciferase activity compared with PC promoter 2 or 3. These data provide information about the arrangement of the 4 bovine PC 5' UTR exons, the identity of the promoter regions for the bovine PC gene, and indicate differences in relative basal activity of the promoter regions.
 ...
PMID:Cloning the genomic sequence and identification of promoter regions of bovine pyruvate carboxylase. 1809 29

The bovine pyruvate carboxylase (PC) gene is expressed as 6 alternatively spliced variants that share a common open reading frame but that differ within their 5' untranslated regions (UTR). The PC 5' UTR variants (A through F) contain 6 combinations of 5 exons and are 68, 253, 363, 89, 226, 178 bp in length, respectively. The objective of this experiment was to determine whether or not the bovine PC mRNA variants exhibit different translational efficiencies. Each bovine PC 5' UTR variant was linked to the firefly luciferase coding region, and the resulting constructs were transcribed and translated in a rabbit reticulocyte lysate assay. All constructs resulted in synthesis of luciferase protein. The abundance of luciferase protein synthesized from the UTR of bovine PC 5' D was greater (P < 0.05) than synthesis from either PC 5' UTR C or E, and the abilities of UTR D, A, B, and F to drive protein translation were similar. The disproportionate contribution to protein synthesis of the PC 5' D UTR compared with UTR variant C or E indicates a complexity of control for PC enzyme synthesis in the bovine that is dependent on the profile of PC variants. These observations are consistent with differences in PC variant expression that have been observed in vivo and indicate that when PC mRNA is elevated, the pattern of variants directs an increase in PC activity through augmented PC enzyme synthesis.
 ...
PMID:Translational efficiency of bovine pyruvate carboxylase 5' untranslated region messenger ribonucleic acid variants. 1859 72