Chromatin stability safeguards mitochondrial homeostasis and restrains TORC1 signaling.

Disruption of histone H3K37 impairs chromatin stability, hyperactivates TORC1, and causes cytotoxicity during TORC1 inhibition in yeast.

• Why it matters: Understanding how chromatin stability influences nutrient signaling pathways like TORC1 is crucial for revealing mechanisms of cellular adaptation and mitochondrial regulation under metabolic stress.
• What they did: Researchers used a histone H3K37A mutant and chromatin stability mutants to analyze effects on histone degradation, TORC1 activity, and mitochondrial signaling, including transcriptome analysis and mitochondrial import assays.
• The result: Findings show chromatin instability leads to TORC1 hyperactivation and mitochondrial retrograde signaling deregulation, with retrograde inactivation and ROS neutralization preventing cytotoxicity, highlighting chromatin's role in restraining TORC1 and maintaining mitochondrial function.