Retinoschisin is discoidin domain-containing protein that is localized along the extracellular surfaces of rod and cone photoreceptors and bipolar cells including the synapses. The retinal Na/K-ATPase acts as a direct interaction partner of retinoschisin, anchoring retinoschisin to retinal plasma membrane. You may use anti-Retinoschisin antibody.
Please refer to the papers attached for your reference.
Article Retinoschisin is linked to retinal Na/K-ATPase signaling and...
Article Retinoschisin Is a Peripheral Membrane Protein with Affinity...