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Regulation of apo A-IV transcription by lipid in newborn swine is associated with a promoter DNA-binding protein
- Source :
- American Journal of Physiology-Gastrointestinal and Liver Physiology. 284:G248-G254
- Publication Year :
- 2003
- Publisher :
- American Physiological Society, 2003.
-
Abstract
- Dietary lipid acutely upregulates apolipoprotein (apo) A-IV expression by sevenfold at the pretranslational level in neonatal swine jejunum. To determine the mechanism of this regulation, two-day-old female swine received intraduodenal infusions of low- and high-triacylglycerol (TG) isocaloric diets for 24 h. Nuclear runoff assay confirmed apo A-IV gene transcriptional regulation by the high-TG diet. Footprinting analysis using the swine apo A-IV proximal promoter sequence (+14 to −246 bp) demonstrated three regions protected by the low-TG extracts. Of these three motifs, only ACCTTC showed 100% homology to the human sequence and was further studied. EMSA was performed using probes containing wild-type (WT) and mutant (M) motifs. A shift was noted with the low-TG nuclear extracts with the WT probe but not with the M probe. Excess unlabeled free WT probe competed out the shift, whereas the M probe did not. No significant shift occurred with either probe using high-TG extracts. These results suggest that a repressor protein binds to the ACCTTC motif and becomes unbound during lipid absorption, allowing transcriptional activation of the apo A-IV gene in newborn swine small intestine.
- Subjects :
- Apolipoprotein B
Swine
Physiology
Molecular Sequence Data
Dietary lipid
Nuclease Protection Assays
Oligonucleotides
Electrophoretic Mobility Shift Assay
Biology
DNA-binding protein
Pregnancy
Transcription (biology)
Physiology (medical)
Gene expression
Animals
Deoxyribonuclease I
Electrophoretic mobility shift assay
Cloning, Molecular
Promoter Regions, Genetic
Apolipoproteins A
Cell Nucleus
Base Sequence
Hepatology
Reverse Transcriptase Polymerase Chain Reaction
Binding protein
Gastroenterology
Promoter
Lipids
Molecular biology
Actins
Diet
DNA-Binding Proteins
Animals, Newborn
biology.protein
Female
Subjects
Details
- ISSN :
- 15221547 and 01931857
- Volume :
- 284
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Gastrointestinal and Liver Physiology
- Accession number :
- edsair.doi.dedup.....e5643b3c18fd0b692dba2df70a60478c
- Full Text :
- https://doi.org/10.1152/ajpgi.00391.2002