Journal article
Lipid deprivation increases surfactant phosphatidylcholine synthesis via a sterol-sensitive regulatory element within the CTP: Phosphocholine cytidylyltransferase promoter
Biochemical journal, Vol.362(1), pp.81-88
2002
DOI: 10.1042/0264-6021:3620081
PMCID: PMC1222362
PMID: 11829742
Abstract
Lipid-deprived mice increase alveolar surfactant disaturated phosphatidylcholine (DSPtdCho) synthesis compared with mice fed a standard diet by increasing expression of CTP:phosphocholine cytidylyltransferase (CCT), the rate-limiting enzyme for DSPtdCho synthesis. We previously observed that lipid deprivation increases mRNA synthesis for CCT [Ryan, McCoy, Mathur, Field and Mallampalli (2000) J. Lipid Res. 41, 1268-1277]. To evaluate regulatory mechanisms for this gene, we cloned the proximal approximately 1900 bp of the 5' flanking sequence of the murine CCT gene, coupled this to a luciferase reporter, and examined transcriptional regulation in a murine alveolar epithelial type II cell line (MLE-12). The core promoter was localized to a region between -169 and +71 bp, which exhibited strong basal activity comparable with the simian virus 40 promoter. The full-length construct, from -1867 to +71, was induced 2-3-fold when cells were cultured in lipoprotein-deficient serum (LPDS), similar to the level of induction of the endogenous CCT gene. By deletional analysis the sterol regulatory element (SRE) was localized within a 240 bp region. LPDS activation of the CCT promoter was abolished by mutation of this SRE, and gel mobility-shift assays demonstrated specific binding of recombinant SRE-binding protein to this element within the CCT promoter. These observations indicate that sterol-regulated expression of CCT is mediated by an SRE within its 5' flanking region.
Details
- Title: Subtitle
- Lipid deprivation increases surfactant phosphatidylcholine synthesis via a sterol-sensitive regulatory element within the CTP: Phosphocholine cytidylyltransferase promoter
- Creators
- Rama K MallampalliAlan J RyanJames L CarrollTimothy F OsborneChristie P Thomas
- Resource Type
- Journal article
- Publication Details
- Biochemical journal, Vol.362(1), pp.81-88
- DOI
- 10.1042/0264-6021:3620081
- PMID
- 11829742
- PMCID
- PMC1222362
- ISSN
- 0264-6021
- eISSN
- 1470-8728
- Language
- English
- Date published
- 2002
- Academic Unit
- Stead Family Department of Pediatrics; Obstetrics and Gynecology; Internal Medicine
- Record Identifier
- 9983985904502771
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