Mislocalization of oligomerization-incompetent RDS is associated with mislocalization of cone opsins and cone transducin

Abstract

RDS (retinal degeneration slow) is a structural protein found in the disk rims of rod and cone photoreceptor outer segments (OSs). Higher-order oligomeric RDS complexes held together by intramolecular disulfide bonds are required for the formation and maintenance of the rim region. Expression of transgenic RDS which cannot form higher-order oligomers (C150S-RDS) leads to dominant, structural, and functional cone degeneration. Furthermore, in this model, C150S-transgenic protein and opsins are mislocalized throughout the cell in cones but not in rods. The purpose of this study was to determine whether other cone OS proteins are mislocalized in the presence of C150S-RDS. Our results demonstrate that all tested proteins are properly localized in the nrl -/- background. In contrast, in the WT background, cone transducin is mislocalized with M- and S-opsin. These results support the hypothesis that C150S-RDS is interfering with the normal transport of cone opsin vesicles. © 2012 Springer Science+Business Media, LLC.