mTORC2 Regulates Actin Polymerization in Auditory Cells

Mammalian target of rapamycin complex 2 (mTORC2) is essential for hearing by regulating auditory hair cell structure and function. However, mechanistic details of how mTORC2 regulates intracellular processes in sensory hair cells have not yet been clarified. To further elucidate the role of mTORC2 in auditory cells, we generated a Rictor knockout cell line from HEI-OC1 auditory cells. mTORC2-deficient auditory cells exhibited significant alterations in actin cytoskeleton morphology and decreased proliferation rates. Additionally, we observed a reduction in phosphorylation of protein kinase C alpha (PKCα) and disrupted actin polymerization in mTORC2-deficient cells. Using proteomics, we found that mTORC2 disruption altered expression of cytoskeleton-related proteins in auditory cells. These findings provide valuable mechanistic insights into the functional role of mTORC2 in auditory cells, potentially opening new perspectives to address sensorineural hearing loss.