RT Journal Article
SR Electronic
T1 Par3 regulates Rac1 signaling and microtubule organization during planar polarization of auditory hair cells
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 323022
DO 10.1101/323022
A1 Andre Landin Malt
A1 Zachary Dailey
A1 Julia Holbrook-rasmussen
A1 Yuqiong Zheng
A1 Quansheng Du
A1 Xiaowei Lu
YR 2018
UL http://biorxiv.org/content/early/2018/05/15/323022.abstract
AB In the inner ear sensory epithelia, hair bundles atop sensory hair cells are mechanosensory apparati with planar polarized structure and orientation. This is established during development by the concerted action of tissue-level planar cell polarity (PCP) signaling and a hair cell-intrinsic, microtubule-mediated machinery. However, how various polarity signals are integrated during hair bundle morphogenesis is poorly understood. Here, we show that the conserved cell polarity protein Par3 plays a key role in planar polarization of hair cells. Par3 deletion in the inner ear resulted in defects in cochlear length, hair bundle orientation and kinocilium positioning. During PCP establishment, Par3 promotes localized Rac-Pak signaling through an interaction with Tiam1. Par3 regulates microtubule dynamics and organization, which is crucial for basal body positioning. Moreover, there is reciprocal regulation of Par3 and the core PCP molecule Vangl2. Thus, we conclude that Par3 is an effector and integrator of cell-intrinsic and tissue-level PCP signaling.One sentence summary Par3 regulates planar polarity of auditory hair cells