Hair cells require phosphatidylinositol 4,5-bisphosphate for mechanical transduction and adaptation

Hirono, Moritoshi, Denis, Charlotte S, Richardson, Guy P and Gillespie, Peter G (2004) Hair cells require phosphatidylinositol 4,5-bisphosphate for mechanical transduction and adaptation. Neuron, 44 (2). pp. 309-320. ISSN 0896-6273

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Abstract

After opening in response to mechanical stimuli, hair cell transduction channels adapt with fast and slow mechanisms that each depend on Ca2+. We demonstrate here that transduction and adaptation require phosphatidylinositol 4,5-bisphosphate (PIP2) for normal kinetics. PIP2 has a striking distribution in hair cells, being excluded from the basal region of hair bundles and apical surfaces of frog saccular hair cells. Localization of a phosphatidylinositol lipid phosphatase, Ptprq, to these PIP2-free domains suggests that Ptprq maintains low PIP2 levels there. Depletion of PIP2 by inhibition of phosphatidylinositol 4-kinase or sequestration by aminoglycosides reduces the rates of fast and slow adaptation. PIP2 and other anionic phospholipids bind directly to the IQ domains of myosin-1c, the motor that mediates slow adaptation, permitting a strong interaction with membranes and likely regulating the motor's activity. PIP2 depletion also causes a loss in transduction current. PIP2 therefore plays an essential role in hair cell adaptation and transduction.

Item Type: Article
Schools and Departments: School of Life Sciences > Neuroscience
Depositing User: Guy Richardson
Date Deposited: 06 Feb 2012 20:11
Last Modified: 26 Mar 2012 08:31
URI: http://sro.sussex.ac.uk/id/eprint/24611
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