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bioRxiv · 10.1101/2020.05.23.112250

Transcriptional re-wiring by mutation of the yeast Hsf1 oligomerization domain

Morton, E. A.·Dorrity, M. W.·Zhou, W.·Fields, S.·Queitsch, C.
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Abstract

Response to heat stress is mediated by heat shock transcription factors (HSFs), which possess conserved DNA-binding and oligomerization domains. The oligomerization domain is required for HSF1 to transition under heat stress from a monomer to a homotrimer, which alters DNA-binding specificity and affinity. Sequence variation in the oligomerization domain affects HSF1 activity, although this link is poorly understood. We performed a deep mutational scan of >400,000 variants of the oligomerization domain of Saccharomyces cerevisiae Hsf1 and measured fitness under stress and non-stress conditions. We identify mutations that confer temperature-specific phenotypes; some exceptional Hsf1variants lead to enhanced growth under heat stress and changes to in vivo DNA-binding and transcriptional programs. The link between Hsf1 oligomerization and DNA-binding domain is evolutionarily conserved, with co-evolving residues between these domains found among fungi. Mutation of transcription factor oligomerization domains may represent a path toward re-wiring transcriptional programs without mutation of DNA-binding domains.

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Morton, E. A., Dorrity, M. W., Zhou, W., Fields, S., Queitsch, C.. 2020-05-25. Transcriptional re-wiring by mutation of the yeast Hsf1 oligomerization domain. https://doi.org/10.1101/2020.05.23.112250

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