Lipid flipping by TMC proteins linked to permanent hearing loss
Feb 27th 2026
Researchers report that the TMC proteins, long seen as sound-to-signal channels, also flip membrane lipids and that this flipping, when triggered by mutations, noise, or certain antibiotics, causes irreversible hair cell death and explains many cases of permanent hearing loss.
- TMC1 and TMC2 act as lipid scramblases that move phospholipids across hair cell membranes.
- Externalization of phosphatidylserine on hair cells triggers apoptosis and kills cells that do not regenerate.
- Genetic mutations, loud noise, and aminoglycoside antibiotics can activate the scramblase function and cause hair cell death.
- Cholesterol levels regulate the scramblase activity, suggesting membrane health could influence vulnerability to damage.
- Knowing this mechanism opens paths to design hearing-safe antibiotics and other therapies to prevent hair cell loss.