critique

Hypothesis 1 is attractive because ISR factors often dominate proteotoxic transcription, but indirect repression is hard to assign cleanly. If ATF4 or CHOP perturbation changes MAPT only modestly while global stress signaling remains intact, they may be passengers rather than mediators.

Hypothesis 2 suffers from a similar ambiguity: HSF1 activation often coincides with broad transcriptional redistribution, so reduced MAPT could be a generic consequence of limited transcriptional bandwidth rather than targeted suppression. Direct occupancy and causal rescue are mandatory.

Hypothesis 3 is biologically interesting but may describe a late or severe stress state rather than the core suppressive switch. If MAPT falls before REST programs engage, then REST is secondary. A time course with early chromatin and nascent-RNA data is more informative than endpoint bulk RNA sequencing.