Abstract |
Holocarboxylase synthetase (HCS) catalyzes the biotinylation of five carboxylases in human cells, and mutations of HCS cause multiple carboxylase deficiency (MCD). Although HCS also participates in the regulation of its own mRNA levels, the relevance of this mechanism to normal metabolism or to the MCD phenotype is not known. In this study, we show that mRNA levels of enzymes involved in biotin utilization, including HCS, are down-regulated during biotin deficiency in liver while remaining constitutively expressed in brain. We propose that this mechanism of regulation is aimed at sparing the essential function of biotin in the brain at the expense of organs such as liver and kidney during biotin deprivation. In MCD, it is possible that some of the manifestations of the disease may be associated with down-regulation of biotin utilization in liver because of the impaired activity of HCS and that high dose biotin therapy may in part be important to overcoming the adverse regulatory impact in such organs.
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Authors | Diana Pacheco-Alvarez, R Sergio Solórzano-Vargas, Roy A Gravel, Rafael Cervantes-Roldán, Antonio Velázquez, Alfonso León-Del-Río |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 279
Issue 50
Pg. 52312-8
(Dec 10 2004)
ISSN: 0021-9258 [Print] United States |
PMID | 15456772
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- DNA, Complementary
- RNA, Messenger
- Biotin
- Carbon-Nitrogen Ligases
- holocarboxylase synthetases
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Topics |
- Animals
- Base Sequence
- Biotin
(deficiency, metabolism)
- Brain
(metabolism)
- Carbon-Nitrogen Ligases
(genetics, metabolism)
- Cell Line
- DNA, Complementary
(genetics)
- Holocarboxylase Synthetase Deficiency
(genetics, metabolism)
- Humans
- Liver
(metabolism)
- Male
- Multiple Carboxylase Deficiency
(genetics, metabolism)
- RNA, Messenger
(genetics, metabolism)
- Rats
- Rats, Wistar
- Tissue Distribution
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