peripherin-2; retinal peripherin; retinal degeneration slow protein; tetraspanin-22; Tspan-22 (PRPH2, PRPH, RDS, TSPAN22)

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Function

may function as an adhesion molecule involved in stabilization & compaction of outer segment disks or in the maintenance of the curvature of the rim
essential for disk morphogenesis
probably forms a complex with a ROM1 homodimer; other proteins could associate with this complex in rods
interacts with MREG

membrane

defects in PRPH2 are the cause of:
- retinitis pigmentosa type 7
- retinitis punctata albescens [MIM:136880]
defects in PRPH2 are a cause of:
mutations underlying autosomal dominant retinitis pigmentosa & severe macular degeneration are largely missense or small in-frame deletions in a large intradiscal loop between the 3rd & 4th transmembrane domains; in contrast, those associated with the milder pattern phenotypes or with digenic retinitis pigmentosa are scattered more evenly through the gene & are often nonsense mutations; this observation correlates with the hypothesis that the large loop is an important site of interaction between PRPH2 molecules & other protein components in the disk