Cryo-EM structures of peripherin-2 and ROM1 suggest multiple roles in photoreceptor membrane morphogenesis.
El Mazouni, D., Gros, P.(2022) Sci Adv 8: eadd3677-eadd3677
- PubMed: 36351012 
- DOI: https://doi.org/10.1126/sciadv.add3677
- Primary Citation of Related Structures:  
7ZW1 - PubMed Abstract: 
Mammalian peripherin-2 (PRPH2) and rod outer segment membrane protein 1 (ROM1) are retina-specific tetraspanins that partake in the constant renewal of stacked membrane discs of photoreceptor cells that enable vision. Here, we present single-particle cryo-electron microscopy structures of solubilized PRPH2-ROM1 heterodimers and higher-order oligomers. High-risk PRPH2 and ROM1 mutations causing blindness map to the protein-dimer interface. Cysteine bridges connect dimers forming positive-curved oligomers, whereas negative-curved oligomers were observed occasionally. Hexamers and octamers exhibit a secondary micelle that envelopes four carboxyl-terminal helices, supporting a potential role in membrane remodeling. Together, the data indicate multiple structures for PRPH2-ROM1 in creating and maintaining compartmentalization of photoreceptor cells.
Organizational Affiliation: 
Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Netherlands.