AUTHOR=Wang Zhongying , Ma Qingping , Lu Jiawen , Cui Xiaochen , Chen Haifeng , Wu Hao , Huang Zhiwu 

TITLE=Functional Parameters of Prestin Are Not Correlated With the Best Hearing Frequency

JOURNAL=Frontiers in Cell and Developmental Biology

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2021.638530

DOI=10.3389/fcell.2021.638530

ISSN=2296-634X

ABSTRACT=Among the vertebrate lineages with different hearing frequency ranges, human lies between the low-frequency hearing (1 kHz) of fish and amphibian and the high-frequency hearing (100 kHz) of bat and dolphin. Little is known about the mechanism underlying such a striking difference in the limits of hearing frequency. Prestin, responsible for cochlear amplification and frequency selectivity in mammals, seems to be the only candidate to date. Mammalian prestin is densely expressed in the lateral plasma membrane of the outer hair cells (OHCs) and functions as a voltage-dependent motor protein. To explore the molecular basis for the contribution of prestin in hearing frequency detection, we collected audiogram datas from human, dog, gerbil, bat and dolphin because their average hearing frequency rises in steps. We generated stable cell lines transfected with human, dog, gerbil, bat and dolphin prestin (hPres, dPres, gPres, bPres and nPres, respectively). The non-linear capacitance (NLC) of different prestins was measured using whole-cell patch-clamp. We found that the Qmax/Clin of bPres and nPres was significantly higher than that of human. The V1/2 of hPres was more hyperpolarized than that of nPres. The z values of hPres and bPres were higher than that of nPres. We further analyzed the relationship between the high-frequency hearing limit (Fmax) and the functional parameters (V1/2, z, and Qmax/Clin) of NLC among five prestins. Interestingly, no significant correlation was found between the functional parameters and Fmax. Additionally, a comparative study showed that the amino acid sequences and tertiary structures of five prestins were quite similar. There might be a common fundamental mechanism driving the function of prestins. These findings call for a reconsideration of the leading role of prestin in hearing frequency perception. Other intriguing kinetics underlying the hearing frequency response of auditory organs might exist.