The p62-CD63 complex mediates amphisome biogenesis for secretory autophagy under oxidative stress

Secretory autophagy transmits pre-existing cytosolic cargoes such as leaderless cytokines via specialized vesicles for cell-to-cell communication as a first-line stress response, necessitating a dynamic and rapid means of membrane initiation and maturation. Here, we report that leaderless cytokines such as interleukins and interferons are substrates of oxidative stress-induced secretory autophagy and exported by amphisomes, whose biogenesis is mediated by the RC ^ox -cytokine-p62-CD63 circuit during oxidative stress. The oxidized N-terminal cysteine residue of cytokines undergoes ATE1-dependent Nt-arginylation and binds the ZZ domain of the autophagic cargo receptor/N-recognin p62/SQSTM1. This conformationally and biologically activates p62 into PB1 domain-mediated oligomeric complexes with the multivesicular body transmembrane tetraspanin CD63 for phagophore-MVB fusion. Peptidomimetic p62 antagonists inhibited secretory autophagy of pro-inflammatory cytokines in cellular, organoid, and murine models of chronic obstructive pulmonary disease. Our results show that p62 within the Cys/N-degron pathway is a central hub and pharmacological target of secretory autophagy.