AUTHOR=Nadar-Ponniah Prathamesh T. , Taiber Shahar , Caspi Michal , Koffler-Brill Tal , Dror Amiel A. , Siman-Tov Ronen , Rubinstein Moran , Padmanabhan Krishnanand , Luxenburg Chen , Lang Richard A. , Avraham Karen B. , Rosin-Arbesfeld Rina TITLE=Striatin Is Required for Hearing and Affects Inner Hair Cells and Ribbon Synapses JOURNAL=Frontiers in Cell and Developmental Biology VOLUME=8 YEAR=2020 URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2020.00615 DOI=10.3389/fcell.2020.00615 ISSN=2296-634X ABSTRACT=

Striatin, a subunit of the serine/threonine phosphatase PP2A, is a core member of the conserved striatin-interacting phosphatase and kinase (STRIPAK) complexes. The protein is expressed in the cell junctions between epithelial cells, which play a role in maintaining cell–cell adhesion. Since the cell junctions are crucial for the function of the mammalian inner ear, we examined the localization and function of striatin in the mouse cochlea. Our results show that in neonatal mice, striatin is specifically expressed in the cell–cell junctions of the inner hair cells, the receptor cells in the mammalian cochlea. Auditory brainstem response measurements of striatin-deficient mice indicated a progressive, high-frequency hearing loss, suggesting that striatin is essential for normal hearing. Moreover, scanning electron micrographs of the organ of Corti revealed a moderate degeneration of the outer hair cells in the middle and basal regions, concordant with the high-frequency hearing loss. Additionally, striatin-deficient mice show aberrant ribbon synapse maturation. Loss of the outer hair cells, combined with the aberrant ribbon synapse distribution, may lead to the observed auditory impairment. Together, these results suggest a novel function for striatin in the mammalian auditory system.