The ITM2B-associated retinal dystrophy mutation modifies BRI23 peptide interactions in the human retina.

BRI23, composed of the 23 last amino acids of the integral transmembrane protein 2B (ITM2B) C-terminus, is associated with several neurodegenerative diseases, including retinal dystrophy (RD) and familial dementia. Its role in the retina remains poorly understood. This study provides a comprehensive analysis of BRI23 interactome in the human retina. Using a peptide-bead coupling system, we identified 2302 proteins, primarily involved in mitochondrial processes, synaptic transmission and photoreceptor function. Our findings show that the BRI23-RD variant, associated with the ITM2B-related RD (IRRD), exhibits significantly altered protein interactions compared to the wild-type form. Notably, we observed an increased abundance of mitochondrial proteins and synaptic molecules, indicating a potential disruption of cellular pathways driven by the IRRD variant.