PDZD7-MYO7A complex identified in enriched stereocilia membranes

Inside the inner ear, sensory cells called hair cells detect and respond to sounds and head movements. These cells have a mechanically sensitive structure called the hair bundle, which is made of many thin projections called stereocilia. The stereocilia are linked so that when they bend in response to a sound or head movement, the whole hair bundle moves as one. A protein called myosin VIIA (MYO7A) is thought to be involved in forming links at the base of stereocilia (so-called ‘ankle links’) and relaying signals from the stereocilia to the rest of the hair cell. However, it is not known how MYO7A interacts with the proteins that make up the ankle links. To address this question. Morgan, Krey et al. developed a new method for isolating groups of proteins from the inner ear of chick embryos that are only found in low quantities. Using this method, it was possible to isolate MYO7A along with other proteins it associates with. One of these proteins – called PDZD7 – is known to be part of ankle links. The next step following on from this work is to use this new method to study other important groups of proteins that are even more scarce in hair bundles.