Naslov
Requirements for chromatin remodeling activities in activation of the yeast PHO84 promoter

Autori
Silić, Bojana ; Korber, Philipp ; Barbarić, Slobodan ; Hoerz, Wolfram

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts of papers presented at the 2005 meeting on Mechanisms of Eukaryotic Transcription / Conaway, Joan ; Graves, Barbara ; Workman Jerry - Lahti : CSHL, Cold Spring Harbor, New York, 2005

Skup
Mechanisms of Eukaryotic Transcription

Mjesto i datum
Cold Spring Harbor (NY), Sjedinjene Američke Države, 31.08.2005. - 04.09.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
chromatin remodeling; yeast PHO84 promoter; transcriptional regulation

Sažetak
We have investigated remodeling of the chromatin structure at the yeast PHO84 promoter, which is coregulated with the well studied PHO5 and PHO8 promoters in response to phosphate availability. The PHO84 promoter is the strongest promoter of the PHO family, containing five binding sites for the specific activator Pho4. Firstly, we analyzed the chromatin structure of this promoter. Under repressive conditions there is a short hypersensitive region in the promoter, containing two closely positioned Pho4 binding sites. Upon induction at least one nucleosome upstream and one downstream from the hypersensitive region are remodeled. This way two additional Pho4 binding sites become accessible. Secondly, we found that the rate of chromatin remodeling and subsequent promoter activation were strongly delayed in mutants deleted for Snf2, Gcn5 or the histone chaperon Asf1. Nonetheless, after prolonged induction full remodeling and activation were achieved in the absence of Gcn5 or Asf1. However, in the absence of Snf2 remodeling remained only partial, resulting in displacement of the downstream but not the upstream nucleosome. Therefore, the PHO84 promoter shows intermediary dependence on Snf2 compared to the two other coregulated promoters. Whereas the PHO5 promoter chromatin structure can be fully remodeled in the absence of Snf2, remodeling at the PHO8 promoter is strictly dependent on Snf2. It was shown previously, that both Snf2 and Ino80 are recruited to the PHO84 promoter upon induction. We found that, however, full remodeling can be achieved in the absence of Ino80. By mutating individual Pho4 binding sites promoter derivatives of decreased strength were obtained and requirements for chromatin opening at these promoters were examined. In all cases the mutations did not affect the chromatin transition pattern in a wild type background, but promoter variants with decreased strength showed much stronger dependence on all chromatin modifying activities tested.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

POVEZANOST RADA