Article

HSP90/70 chaperones are required for rapid nucleosome removal upon induction of the GAL genes of yeast.

Molecular Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10021, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 03/2008; 105(8):2975-80. DOI: 10.1073/pnas.0800053105
Source: PubMed

ABSTRACT Induction of transcription of the GAL genes of yeast by galactose is a multistep process: Galactose frees the activator Gal4 of its inhibitor, Gal80, allowing Gal4 to recruit proteins required to transcribe the GAL genes. Here, we show that deletion of components of either the HSP90 or the HSP70 chaperone machinery delays this induction. This delay remains when the galactose-signaling pathway is bypassed, and it cannot be explained by a chaperone requirement for DNA binding by Gal4. Removal of promoter-bound nucleosomes is delayed in a chaperone mutant, and our findings suggest an involvement of HSP90 and HSP70 in this early step in gene induction.

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