Cooperativity of K v 7.4 channels confers ultrafast electromechanical sensitivity and emergent properties in cochlear outer hair cells
Open Access
- 10 April 2020
- journal article
- research article
- Published by American Association for the Advancement of Science (AAAS) in Science Advances
- Vol. 6 (15), eaba1104
- https://doi.org/10.1126/sciadv.aba1104
Abstract
The mammalian cochlea relies on active electromotility of outer hair cells (OHCs) to resolve sound frequencies. OHCs use ionic channels and somatic electromotility to achieve the process. It is unclear, though, how the kinetics of voltage-gated ionic channels operate to overcome extrinsic viscous drag on OHCs at high frequency. Here, we report ultrafast electromechanical gating of clustered Kv7.4 in OHCs. Increases in kinetics and sensitivity resulting from cooperativity among clustered-Kv7.4 were revealed, using optogenetics strategies. Upon clustering, the half-activation voltage shifted negative, and the speed of activation increased relative to solitary channels. Clustering also rendered Kv7.4 channels mechanically sensitive, confirmed in consolidated Kv7.4 channels at the base of OHCs. Kv7.4 clusters provide OHCs with ultrafast electromechanical channel gating, varying in magnitude and speed along the cochlea axis. Ultrafast Kv7.4 gating provides OHCs with a feedback mechanism that enables the cochlea to overcome viscous drag and resolve sounds at auditory frequencies.Funding Information
- National Institutes of Health (R01 DC006685)
- National Institutes of Health (R56 HL138392)
- National Institutes of Health (HL136120)
- National Institute on Aging (AG051443, AG060504)
- U.S. Department of Veterans Affairs (I01 BX000576 and I01 CX001490)
- NHLBI (HL085727, HL085844, HL137228, HL086350)
- NIDCD (DC016099, DC05135, DC015252)
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