RABGEF1 and retinal degeneration: In conclusion, our studies uncover a direct and critical role of RabGEF1 in the endocytic and autophagic pathways during functional maturation of mammalian photoreceptors and demonstrate that the loss of RabGEF1 leads to photoreceptor developmental defects and relatively fast retinal degeneration likely because of compromised recycling and proteostasis.