The BioGRID | PUBLICATION VIEW

	J. Biol. Chem. Feb (2004); 279(8):7091-7
Histone acetyltransferase-dependent chromatin remodeling and the vascular clock.
Curtis AM, Seo SB, Westgate EJ, Rudic RD, Smyth EM, Chakravarti D, FitzGerald GA, McNamara P
Center for Experimental Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Abstract: Rhythmic gene expression is central to the circadian control of physiology in mammals. Transcriptional activation of Per and Cry genes by heterodimeric bHLH-PAS proteins is a key event in the feedback loop that drives rhythmicity; however, the mechanism is not clearly understood. Here we show the transcriptional coactivators and histone acetyltransferases, p300/CBP, PCAF, and ACTR associate with the bHLH-PAS proteins, CLOCK and NPAS2, to regulate positively clock gene expression. Furthermore, Cry2 mediated repression of NPAS2:BMAL1 is overcome by overexpression of p300 in transactivation assays. Accordingly, p300 exhibits a circadian time-dependent association with NPAS2 in the vasculature, which precedes peak expression of target genes. In addition, a rhythm in core histone H3 acetylation on the mPer1 promoter in vivo correlates with the cyclical expression of their mRNAs. Temporal coactivator recruitment and HAT-dependent chromatin remodeling on the promoter of clock controlled genes in the vasculature permits the mammalian clock to orchestrate circadian gene expression.
[PUBMED: 14645221]