1H, 13C and 15N backbone resonance assignments and dynamic properties of the PDZ tandem of Whirlin

Mammals perceive sounds thanks to mechanosensory hair cells located in the inner ear. The stereocilia of these cells are tightly bound together in bundles by a network of cadherins and scaffolding proteins. Stereocilia deflection induces stretching of this network and is responsible for hair cell depolarization that triggers the neuronal message, transducing the mechanical signal into an electric signal transmissible to the brain. Nearly all proteins involved in this mechano-electrical transduction network contain short C-terminal motifs of interaction with PDZ domains (PSD-95, Discs Large, ZO-1). Interestingly only two of these proteins encompass PDZ domains: Harmonin and Whirlin. As our first step towards a comprehensive structural study of Whirlin, we have assigned the H-1, C-13 and N-15 backbone resonances of a tandem formed by the first two PDZ domains of Whirlin, reported the secondary structure elements of this tandem as predicted by the TALOS+ server and evaluated its dynamics from N-15 relaxation measurements.