¹The Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China

Correspondence: Jun Lu, Tel: +86-431-5099798; Fax: +86-431-5681833; E-mail: ycsuo@nenu.edu.cn, luj809@nenu.edu.cn

^*These authors contributed equally to the work.

Received 22 September 2005; Revised 18 February 2006; Accepted 20 March 2006.

Abstract

Histone acetyltransferases/deacetylases contribute to the activation or inactivation of transcription by modifying the structure of chromatin. Here we examined the effects of histone deacetylase inhibitors (HDIs), trichostatin A, and sodium butyrate on hsp70 gene transcriptional regulation in Drosophila. The chromatin immunoprecipitation assays revealed that HDI treatments induced the hyperacetylation of histone H3 at the promoter and the transcribing regions of hsp70 gene, increased the accessibility of heat-shock factor to target heat-shock element, and promoted the RNA polymerase II-mediated transcription. Moreover, the quantitative real-time PCR confirmed that the HDI-induced hyperacetylation of histone H3 enhanced both the basal and the inducible expression of hsp70 mRNA level. In addition, the acetylation level of histone H3 at the promoter exhibited a fluctuated change upon the time of heat shock. These experimental data implicated a causal link between histone acetylation and enhanced transcription initiation of hsp70 gene in Drosophila.