Reversal of methylation-mediated repression with short-chain fatty acids: evidence for an additional mechanism to histone deacetylation

Citation
D. Benjamin et Jp. Jost, Reversal of methylation-mediated repression with short-chain fatty acids: evidence for an additional mechanism to histone deacetylation, NUCL ACID R, 29(17), 2001, pp. 3603-3610
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
NUCLEIC ACIDS RESEARCH
ISSN journal
0305-1048 → ACNP
Volume
29
Issue
17
Year of publication
2001
Pages
3603 - 3610
Database
ISI
SICI code
0305-1048(20010901)29:17<3603:ROMRWS>2.0.ZU;2-F
Abstract
We have constructed a stable cell line, human embryonal kidney 293M(+), con taining a lacZ reporter gene controlled by an in vitro methylated hormone-r esponsive enhancer. Methylation of the enhancer-promoter abolishes lacZ exp ression controlled by ponasterone A (an analogue of ecdysone). Ponasterone A-induced expression is restored by the short-chain fatty acids valeric > b utyric > proplonic > acetic acid, but not by the histone deacetylase inhibi tors trichostatin A and suberoylanilide hydroxamic acid (SAHA). lacZ expres sion is restored to levels approaching that from an unmethylated counterpar t. Incubation with short-chain fatty acids alone does not promote demethyla tion of the lacZ promoter, however, some demethylation (30%) is observed wh en transcription is triggered by addition of ponasterone A. Similar levels of hyperacetylated histones H3 and H4 were observed in cells treated with s hort-chain fatty acids, trichostatin A or SAHA. In vivo DNase I footprintin g indicates a more open chromatin structure at the promoter region for buty ric acid-treated cells. A synergistic effect in reversing the methylation-m ediated repression of the lacZ gene is obtained by combined treatments with the normally ineffective compounds trichostatin A and the short-chain fatt y acid caproic acid. Our results suggest the existence of an alternative si lencing mechanism to histone deacetylation in executing methylation-directe d gene silencing.