Myosin IXA (MYO9A)

MYO9A is predicted to contain the ATP-binding loop and light chain-binding region typical of myosins, as well as the domains characteristic of class IX unconventional myosins, including an N-terminal extension, an insertion in the head domain, and a GAP domain. In addition, compared to the class IX unconventional myosins human MYO9B and rat Myr5, MYO9A contains numerous insertions. Two of these insertions conform to the """IQ motif,""" suggesting that MYO9A may bind 6 light chains of the calmodulin/EF-hand superfamily instead of the 4 that MYO9B and Myr5 are predicted to bind.Myo9a transcripts were also found in the inner ear, kidney, thyroid gland, and teeth.In situ hybridization of the adult mouse retina detected Myo9a expression in the ganglion cell layer but not in the bipolar cell layer or the cell bodies of rods and cones.