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Updated: Aug 8, 2026

In Vivo Calcium Imaging of Lateral-line Hair Cells in Larval Zebrafish
Published on: November 28, 2018
Myosin-1c interacts with hair-cell receptors through its calmodulin-binding IQ domains
Janet L Cyr1, Rachel A Dumont, Peter G Gillespie
1Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, Oregon 97201, USA.
Abstract:
Myosin-1c plays an essential role in adaptation of hair-cell mechanoelectrical transduction. To mediate adaptation, myosin-1c must interact directly or indirectly with other components of the transduction apparatus, including the mechanically gated transduction channel. As a first step toward identifying myosin-1c receptors, we used recombinant myosin-1c fragments to identify specific binding sites in hair cells and to biochemically characterize their interaction with myosin-1c. Myosin-1c fragments bound to tips of hair-cell stereocilia, the location of transduction and adaptation. Surprisingly, this interaction did not depend on the C-terminal tail of myosin-1c, proposed previously to be the receptor-binding site of the molecule. Instead, the interaction of myosin-1c with stereociliary receptors depended on its calmodulin-binding IQ domains. This interaction was blocked by calmodulin, which probably bound to a previously unoccupied IQ domain of myosin-1c. The calcium-sensitive binding of calmodulin to myosin-1c may therefore modulate the interaction of the adaptation motor with other components of the transduction apparatus.
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