Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2017/06 -2019/03
Author : Ugawa Shinya
We identified a putative mechanosensory channel ASIC-X in mouse auditory hair cells, and explored its channel properties using a combination of electrophysiology and ratio-imaging techniques with fura-2 and SBFI. Although the leakage currents of heterologously expressed ASIC-X were augmented by strong shear stress, neither hypotonicity nor direct stretching of plasma membrane enhanced the currents. Mechanoelectrical transduction (MET) currents in outer hair cells (OHCs) of ASIC-X knockout mice did not significantly change in the amplitude, compared to MET currents in wild-type OHCs, which is in good agreement with the in vitro data. However, our investigations revealed that the ASIC-X channel was selective to sodium ions. Therefore, ASIC-X is most likely to function as a sodium leak channel in vivo rather than as a mechanosensitive molecule. The tissue distribution of the channel should be clarified in detail next.