Preparation and Analysis of Saccharomyces cerevisiae Quiescent Cells.

Saccharomyces cerevisiae enter quiescence during extended growth in culture (greater than 7 days). Here, we describe a method to separate quiescent from non-quiescent cells by density gradient. We also describe approaches for DAPI staining the chromatin of quiescent cells, measuring quiescent cell viability, and extracting RNA from quiescent cells for use in genomics experiments.

The RSC complex localizes to coding sequences to regulate Pol II and histone occupancy.

ATP-dependent chromatin remodelers regulate chromatin structure during multiple stages of transcription. We report that RSC, an essential chromatin remodeler, is recruited to the open reading frames (ORFs) of actively transcribed genes genome wide, suggesting a role for RSC in regulating transcription elongation. Consistent with such a role, Pol II occupancy in the ORFs of weakly transcribed genes is drastically reduced upon depletion of the RSC catalytic subunit Sth1.

A role for phosphorylated Pol II CTD in modulating transcription coupled histone dynamics.

Histone acetylation modulates histone occupancy both at promoters and in coding sequences. Based on our recent observation that HDACs in the budding yeast, Saccharomyces cerevisiae, are co-transcriptionally recruited to coding regions by elongating polymerases, we propose a model in which Pol II facilitates recruitment of chromatin remodeling complexes as well as other factors required for productive elongation.

Drosophila SIN3 isoforms interact with distinct proteins and have unique biological functions.

The SIN3 corepressor serves as a scaffold for the assembly of histone deacetylase (HDAC) complexes. SIN3 and its associated HDAC have been shown to have critical roles in both development and the regulation of cell cycle progression. Although multiple SIN3 isoforms have been reported in simple to complex eukaryotic organisms, the mechanisms by which such isoforms regulate specific biological processes are still largely uncharacterized.