Coiled-coil homo-oligomerization and disaggregase Hsp104 act in parallel to stabilize orphan septins

Orphan yeast septins are stabilized by coiled-coil homodimers, trimers, and the disaggregase Hsp104, preventing aggregation and proteasomal degradation.

• Why it matters: Maintaining septin subunit stoichiometry is crucial for proper assembly, yet orphan septins tend to aggregate and are linked to neurodegenerative disease pathology, highlighting the importance of cellular quality control mechanisms.
• What they did: The study examined how orphan septins are protected by forming transient coiled-coil homodimers and trimers, and by Hsp104, especially when septins cannot undergo CTD-mediated homo-oligomerization; septin mRNA levels and localization were also analyzed.
• The result: Findings suggest that coiled-coil formation and Hsp104 activity are key to septin proteostasis, enabling higher-order assembly fidelity and preventing pathological aggregation in cells.