ReviewEndoplasmic reticulum stress in human photoreceptor diseases

- ER stress and UPR are pathomechanisms of rod and cone photoreceptor diseases.
- Rhodopsin misfolding is a cause of rod photoreceptor disease, retinitis pigmentosa.
- Rod photoreceptors degrade misfolded rhodopsin through ERAD.
- ATF6 mutations are a novel cause of cone photoreceptor disease, achromatopsia.
- Achromatopsia mutations target sequential steps of ATF6 activation.

Photoreceptors are specialized sensory neurons essential for light detection in the human eye. Photoreceptor cell dysfunction and death cause vision loss in many eye diseases such as retinitis pigmentosa and achromatopsia. Endoplasmic reticulum (ER) stress and Unfolded Protein Response (UPR) signaling have been implicated in the development and pathology of heritable forms of retinitis pigmentosa and achromatopsia. We review the role of ER stress and UPR in retinitis pigmentosa arising from misfolded rhodopsins (RHO) and in achromatopsia arising from genetic mutations in Activating Transcription Factor 6 (ATF6).This article is part of a Special Issue entitled SI:ER stress.