Probably associates with an alpha chain. Interacts (via C-terminus) with TRPC4. Detected prominently in the outer segments of photoreceptor rods and cones and in the basolateral membrane and cytosol of gastric epithelial cells. Expressed at very low levels in many tissues, with strongest expression in cerebellum, spinal cord, stomach, pituitary gland, liver, pancreas, salivary gland, kidney, bladder, and heart. Belongs to the spectrin family.