The study indicated that the protein called harmonin, which is known to be involved in sound sensing in the inner ear, may also play a role in the transmission of sound information to the brain.
Harmonin is thought to mediate this movement, which then activates the cells and initiates transmission of sound information as electrical and chemical signals to the brain.
Now we have found a new role for harmonin at the opposite end of these sound-sensing inner hair cells where it appears to control the signal output of the cell," added Lee.
found that harmonin is important for regulating the number of calcium channels present at the sound-transmitting synapse of inner hair cells.
What we think is happening in Usher syndrome where the harmonin protein is mutated is that there are too many calcium channels available, which causes abnormal signaling at the synapses.
The intracellular domain of this variant is able to bind to the PDZ module-containing proteins harmonin and whirlin, which are proposed to anchor usherin to the actin-based cytoskeleton via myosin VII (Adato et al, 2005a).
There is some evidence that the intracellular domain of mammalian usherin interacts with the PDZ-containing proteins harmonin and whirlin, which are proposed to act as a link between usherin and microfilaments (Adato et al.