This is a great review paper on the role of rhodopsin trafficking and its influence on retinal degenerative disease by TJ Hollingsworth and Alecia Gross. Rhodopsin delocalization in rod photoreceptors has been recognized for some time as one of the first indications of retinal photoreceptor cell stress in retinal degenerative diseases, so I was intrigued when seeing this paper come up in PubMed. One of the fundamental questions with rhodopsin delocalization is what role the delocalized rhodopsin takes in the etiology of retinal degenerations and this review attempts to address some of those questions in a coherent manner.
After talking with Alicia, she nicely summarized her thoughts: “One of the most fundamental problems in molecular neuroscience and cell biology is the proper assembly of signal-transducing membranes, including the transport and sorting of protein components. A major cause of neurodegenerative and other inherited disorders is the improper localization of receptors. Mislocalization of the dim-light photoreceptor protein rhodopsin is a phenotype observed in many forms of the blinding disease retinitis pigmentosa, but to date, it is not certain if mislocalized rhodopsin acts as a contributing factor to the apoptotic cell death. This review focuses on the mutations associated with RP with emphasis on those exhibiting rhodopsin mislocalization as a molecular phenotype”. ~Alecia Gross.
Image credit: Joshua Sammons and Alecia K Gross. These are immunostained images of cryosections taken from either a wild type mouse eye or a rhodopsin-Q344ter knock-in mouse to show the rhodopsin mislocalization in the knock-in animals.