CEP290 and Leber congenital amaurosis: In this study, we analyzed ISR signaling in the retinas of rd16 mice, a model of LCA harboring a 5-exon deletion in Cep290. A variety of stress responses including endoplasmic reticulum (ER) stress, amino acid starvation, and viral infection lead to the activation of one or more kinases that phosphorylate the α-subunit of eukaryotic translation initiation factor 2 (eIF2α) at serine 51.