Rpgr, short for Retinitis Pigmentosa GTPase Regulator, is involved in ciliary function within photoreceptor connecting cilia in mammalian eyes [1]. Mutations in this gene are a common cause of inherited retinal dystrophy retinitis pigmentosa (RP), affecting 10-20% of all RP cases and the majority of X-linked RP cases [1]. It may play a role in the ciliary gate, controlling protein access to the photoreceptor outer segment, and is also a guanine nucleotide exchange factor for the small GTPase RAB37, regulating autophagy to maintain retinal function [1,2].

In Rpgr knockout (KO) mice, photoreceptor degeneration occurs due to autophagy impairment in the retina [2]. The retinopathy phenotypes of these KO retinas can be rescued by adeno-associated virus-mediated transfer of pre-trans-splicing molecules, which re-express normal Rpgr mRNAs and upregulate autophagy, restoring retinal homeostasis [2].

In conclusion, Rpgr is essential for maintaining retinal function, mainly through its role in ciliary function and autophagy regulation. Studies using Rpgr KO mouse models have significantly contributed to understanding its role in retinal diseases like retinitis pigmentosa, providing insights into potential therapeutic strategies for these conditions [2].