Heat Shock Factor 1 Governs Sleep-Wake Cycles Across Species

Heat Shock Factor 1 (HSF1) is a critical transcription factor for cellular proteostasis, but its role in sleep regulation remains unexplored. We demonstrate that nuclear HSF1 levels in the mouse brain fluctuate with sleep-wake cycles, increasing during extended wakefulness and decreasing during sleep. Using CUT&RUN and RNA-seq, we identified HSF1-regulated transcriptional changes involved in synaptic organization, expanding its known functions beyond traditional heat shock responses. Both systemic and brain-specific