An HSF1-JMJD6-HSP feedback circuit promotes cell adaptation to proteotoxic stress [RNA-Seq]

Heat Shock Factor 1 (HSF1) is best known as the master transcriptional regulator of the heat-shock response (HSR), a conserved adaptive mechanism critical for protein homeostasis (proteostasis). Combining a genome-wide RNAi library with an HSR reporter, we identified JMJD6 as an essential mediator of HSF1 activity. In follow-up studies, we found that JMJD6 is itself a non-canonical transcriptional target of HSF1 which acts as a critical regulator of proteostasis. In a positive feedback circuit, HSF1 binds and promotes JMJD6 expression, which in turn reduces HSP70 R469 monomethylation to disrupt HSP70-HSF1 repressive complexes resulting in enhanced HSF1 activation. Thus, JMJD6 is intricately wired into the proteostasis network where it plays a critical role for cellular adaptation to proteotoxic stress.