Epigenetic changes in transcribed regions of the genes, such as DNA methylation, covalent modifications of histones, and ATP-dependent chromatin remodeling, have been recently identified as key universal components that regulate gene expression. Among these epigenetic modificators are large protein ensembles RSC, Swi/Snf, iSwi and histone modification factors that increase accessibility of chromatin to transcription. RNA polymerase itself and the associated transcription elongation factors may also work to establish and maintain the active state of the chromatin.The major results: 1. The yeast chromatin-remodeling complex RSC reduces nucleosomal barrier to Pol II in vitro. The mechanism of the reduction is currently being investigated.2. The yeast transcript cleavage factor TFIIS facilitates transcription through nucleosomes by Pol II. RSC and TFIIS cooperate in the process.3. We determine the fate of nucleosomes after factor-stimulated transcription by Pol II.
| Lewis, Dale E A; Komissarova, Natalia; Le, Phuoc et al. (2008) DNA sequences in gal operon override transcription elongation blocks. J Mol Biol 382:843-58 |
| Kireeva, Maria L; Hancock, Brynne; Cremona, Gina H et al. (2005) Nature of the nucleosomal barrier to RNA polymerase II. Mol Cell 18:97-108 |
| Studitsky, Vasily M; Walter, Wendy; Kireeva, Maria et al. (2004) Chromatin remodeling by RNA polymerases. Trends Biochem Sci 29:127-35 |
| Kireeva, Maria L; Lubkowska, Lucyna; Komissarova, Natalia et al. (2003) Assays and affinity purification of biotinylated and nonbiotinylated forms of double-tagged core RNA polymerase II from Saccharomyces cerevisiae. Methods Enzymol 370:138-55 |
