Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.4.1.2 (acetyl-CoA carboxylase)
 2,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of the alpha-thyroid hormone receptor (TR alpha) in regulation of transcription of the gene for chicken malic enzyme was analyzed in fibroblast cell lines normally unresponsive to triiodothyronine (T3). The gene for this transcription factor was introduced stably and overexpressed using a replication-competent retroviral vector. In chick embryo fibroblasts (CEF), overexpression of TR alpha decreased malic enzyme activity by 90% in the absence of T3. Addition of T3 almost completely restored malic enzyme activity to the level of similarly treated control CEF infected with virus lacking TR alpha. These TR alpha-induced changes in malic enzyme activity were mediated by alterations in transcription of the malic enzyme gene. Similar results were obtained when transcriptional activity of TR alpha was analyzed using a transient co-transfection system. Thus, the unliganded TR alpha is a transcriptional repressor of the malic enzyme gene; binding of T3 to the receptor abolishes this repression. In contrast, stable overexpression of TR alpha in QT6 cells had no effect on malic enzyme expression in the absence or presence of T3. Nuclear T3 binding was equally high in CEF and QT6 cells overexpressing TR alpha. These findings suggest that cell-specific factors control the ability of TR alpha to regulate the malic enzyme gene. Overexpression of TR alpha in CEF had no effect on the expression of fatty acid synthase and acetyl-CoA carboxylase, lipogenic enzymes that are stimulated by T3 in hepatocytes in culture. Thus, gene-specific factors also may control the transcriptional activity of TR alpha.
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PMID:Overexpression of the alpha-thyroid hormone receptor in avian cell lines. Effects on expression of the malic enzyme gene are selective and cell-specific. 135 Oct 57

We have recently reported that intake of soya protein isolate (SPI) inhibited the DNA-binding activities of hepatic thyroid hormone receptor (TR). The genes for acetyl-CoA carboxylase (ACC), a rate-limiting enzyme in fatty acid synthesis, contain the thyroid hormone response element in their promoters and are regulated by TR. The present study has examined the effect of long-term feeding of SPI and soya isoflavones (ISF) on the gene expression and protein phosphorylation of different ACC isoforms in different tissues and plasma triacylglycerol (TAG) levels in rats. Sprague-Dawley female rats were fed diets containing 20 % casein or alcohol-washed SPI with or without supplemental ISF for 70, 190 and 310 d. SPI intake significantly reduced plasma TAG concentrations compared with casein, whereas supplemental ISF had no effect. Hepatic ACCalpha and ACCbeta mRNA abundance and protein content were markedly lower in the rats fed SPI than in those fed casein. The protein contents of ACCalpha in the kidney and ACCbeta, the predominant isoform in the heart and kidney, were unchanged by dietary SPI. The ratios of phospho-ACCalpha/ACCalpha and phospho-ACCbeta/ACCbeta were not different among dietary groups in all tissues measured. The present study demonstrates that ingestion of SPI decreases plasma TAG level and down-regulates ACCalpha and ACCbeta gene expression in the liver but not in the heart and kidney. The results indicate that the effect of SPI is tissue-specific and that alteration of ACC gene expression rather than phosphorylation status may play a major role in the regulation of ACC activities by soya proteins.
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PMID:Tissue-specific regulation of acetyl-CoA carboxylase gene expression by dietary soya protein isolate in rats. 1676 25