Back to Search
Start Over
Genomic distribution of three promoters of the bovine gene encoding acetyl-CoA carboxylase alpha and evidence that the nutritionally regulated promoter I contains a repressive element different from that in rat.
- Source :
-
The Biochemical journal [Biochem J] 2001 Aug 15; Vol. 358 (Pt 1), pp. 127-35. - Publication Year :
- 2001
-
Abstract
- The enzyme acetyl-CoA carboxylase alpha (ACC-alpha) is rate-limiting for the synthesis of long-chain fatty acids de novo. As a first characterization of the bovine gene encoding this enzyme, we established the entire bovine ACC-alpha cDNA sequence (7041 bp) and used experiments with 5' rapid amplification of cDNA ends to determine the heterogeneous composition of 5' untranslated regions, as expressed from three different promoters (PI, PII and PIII). The individual locations of these promoters have been defined within an area comprising 35 kbp on Bos taurus chromosome 19 ('BTA19'), together with the segmentation of the first 14 exons. Primer extension analyses reveal that the nutritionally regulated PI initiates transcription from at least four sites. PI transcripts are much more abundant in adipose and mammary-gland tissues than in liver or lung. A 2.6 kb promoter fragment drives the expression of reporter genes only weakly in different model cells, irrespective of stimulation with insulin or dexamethasone. Thus bovine PI is basically repressed, like its analogue from rat. Finely graded deletions of PI map two separate elements, which have to be present together in cis to repress bovine PI. The distal component resides within a well-preserved Art2 retroposon element. Thus sequence, structure and evolutionary origin of the main repressor of PI in bovines are entirely different from its functional counterpart in rat, which had been identified as a (CA)(28) microsatellite. We show that, in different mammalian species, unrelated genome segments of different origins have been recruited to express as functionally homologous PI the ancient and otherwise highly conserved ACC-alpha-encoding gene.
- Subjects :
- Acetyl-CoA Carboxylase biosynthesis
Adipose Tissue metabolism
Animals
Base Sequence
Breast metabolism
Cattle
Chromosome Mapping
DNA, Complementary metabolism
Dexamethasone pharmacology
Exons
Gene Deletion
Genes, Reporter
Insulin pharmacology
Liver metabolism
Luciferases metabolism
Lung metabolism
Microsatellite Repeats
Models, Genetic
Molecular Sequence Data
Nutritional Physiological Phenomena
RNA, Messenger metabolism
Rats
Retroelements genetics
Reverse Transcriptase Polymerase Chain Reaction
Tissue Distribution
Transfection
Acetyl-CoA Carboxylase chemistry
Acetyl-CoA Carboxylase genetics
Promoter Regions, Genetic
Subjects
Details
- Language :
- English
- ISSN :
- 0264-6021
- Volume :
- 358
- Issue :
- Pt 1
- Database :
- MEDLINE
- Journal :
- The Biochemical journal
- Publication Type :
- Academic Journal
- Accession number :
- 11485560
- Full Text :
- https://doi.org/10.1042/0264-6021:3580127