VPS26A retromer complex and SNX27 mediate stress-induced Golgi bypass of membrane proteins

Le résumé fourni par la source

Many proteins can reach the cell surface through a Golgi-independent unconventional protein secretion (UPS) pathway, particularly under cellular stress conditions. However, the molecular mechanisms that mediate UPS remain largely elusive. In this study, VPS26A-containing retromer complex, along with the sorting nexin SNX27, is identified as a regulator of UPS of transmembrane proteins, including the trafficking-deficient ∆F508 mutant CFTR, which causes cystic fibrosis, and the SARS-CoV-2 spike protein, associated with COVID-19. A targeted CRISPR knockout screen identified VPS26A as a key contributor in the UPS of ∆F508-CFTR. Subsequent molecular analyses revealed that SNX27 recruits ∆F508-CFTR to the VPS26A-VPS35-VPS29 retromer complex, facilitating its transport to the cell surface under UPS-inducing conditions. Additionally, VPS26A and SNX27 are necessary for UPS of the spike protein, enabling the formation of intact SARS-CoV-2 virions. These findings suggest that the retromer complex and SNX27, known for their roles in recycling endosomes, mediate previously unrecognized functions in the UPS of transmembrane proteins.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.