Naslov
An essential, and promoter-specific role of the RSC complex for physiological induction of the yeast PHO5 promoter

Autori
Musladin, Sanja ; Novačić, Ana ; Hlevnjak, Dora ; Budimir, Jelena ; Korber, Philipp ; Barbarić, Slobodan

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

Izvornik
Program & Abstract Book „Chromatin and Epigenetics: from Mechanism to Function“ / Torres-Padilla, Maria Elena ; Schneider, Robert - München, 2017, P5-P5

Skup
Chromatin and Epigenetics: from Mechanism to Function

Mjesto i datum
München, Njemačka, 05.04.2017. - 07.04.2017

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
RSC complex, chromatin remodeling, yeast PHO promoters

Sažetak
The yeast PHO5 promoter is one of the best characterized examples of a massive chromatin structure transition that precedes activation of gene transcription (1). We showed recently that a network of five remodeling complexes including the RSC complex is involved in chromatin remodeling at this promoter (2). RSC inactivation did not affect chromatin remodeling at the PHO8 and PHO84 promoters, which are activated by the same activator as the PHO5 promoter. Nonetheless, we postulated that the RSC complex has a major role in opening the PHO5 promoter. To distinguish if this role is important or even essential we applied a new strategy for more complete depletion of RSC activity in vivo. We combined the thermal inactivation of the degron-tagged catalytic RSC subunit Sth1td, which was used in our previous study, with the viable deletion allele of the Rsc2 subunit of the major RSC isoform. In this double rsc2 sth1td mutant, inactivation of RSC was so strong that chromatin remodeling at the PHO5 promoter was fully prevented, and not just delayed as previously found for the sth1td single mutant (2). This was not due to secondary effects on signal transduction or transactivator function as the same was true for chromatin remodeling at a Gal4-driven PHO5 promoter variant. Further, RSC remodeling activity was not only required for initial promoter opening but also for the maintenance of the open chromatin state. Interestingly, even in the case of this more complete depletion of RSC activity in the rsc2 sth1td double mutant chromatin remodeling at the PHO8 and PHO84 promoters was still hardly affected. This argues that the critical requirement for the RSC remodeling activity at the PHO5 promoter is related to specific chromatin structure features at this promoter. However, this critical role of RSC at the PHO5 promoter upon physiological induction did not seem to be due to a mechanistically essential role. Increased recruiting and activation potential by overexpression of the Pho4 activator resulted in substantial chromatin opening and consequent activation of the PHO5 promoter even under fully restrictive conditions in the rsc2 sth1td mutant. Observed RSC-independent chromatin opening was mostly due to the activity of the SWI/SNF complex. This showed that appreciable chromatin remodeling at the PHO5 promoter cannot occur in vivo without participation of remodeling complexes and that the contribution of the RSC complex is of critical importance but can be replaced mechanistically by other remodelers. References: (1) Korber P, Barbaric S. Nucleic Acids Res. 2014, 42:10888-10902. (2) Musladin S, Krietenstein N, Korber P, Barbaric S. Nucleic Acids Res. 2014, 42:4270-4282.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

POVEZANOST RADA