QR-421a is designed to restore functional Usherin
protein by using an exon skipping approach with the aim to stop or reverse vision loss in patients.
The USH2A gene encodes a protein, usherin
, which is believed to be important in the development and maintenance of cells in the retina and the inner ear.
PDZD7 has been shown to bind the three known USH2 proteins usherin (USH2A), ADGRV1 (USH2C), and whirlin (USH2D), forming the so-called ankle-link complex at the ankle region of hair cell stereocilia [17, 21-23].
At present, only a few PDZD7-binding proteins have been reported, including usherin, ADGRV1, whirlin, harmonin, SANS, and MYO7A [17, 18, 21-25].
Expression of usherin
in the anthozoan Nematostella vectensis.
One of the genes responsible for Usher Syndrome II encodes the protein usherin (Eudy et al, 1998; Bhattacharya et al, 2002).
Though we were unable to find cnidarian orthologs of tenascin, we did discover a predicted protein with a domain organization identical to that found in the amino half of vertebrate usherin. Here we describe that predicted protein as well as an adjacent predicted gene that, when considered together, encode a single predicted protein with the same general domain organization as the transmembrane variant of vertebrate usherin.
The nN2A Nematostella usherin plasmid was selected to generate probes for in situ hybridization.
vectensis sequences encoding predicted proteins with an architecture similar to portions of vertebrate usherin were found using the program Superfamily 1.69 (Gough et al., 2001).