Thr308-dephosphorylated AKT1 licenses SQSTM1-LC3C-mediated antiviral autophagy

AKT1 is classically known as a serine/threonine kinase controlling cell survival and proliferation, yet its kinase-independent functions remain poorly understood. Here we show that recognition of dsRNA viral capsids by membrane-associated HSP90AA1 disrupts the HSP90-AKT1 interaction, inducing AKT1 dephosphorylation at Thr308. This non-phosphorylated AKT1 acts as a scaffold to recruit PDPK1 and SQSTM1, enabling PDPK1-dependent phosphorylation of SQSTM1 at Ser349 and selective loading of viral capsids into LC3C-positive phagophores for degradation. An IBDV capsid mutant defective in SQSTM1 binding escapes this pathway. In vivo, expression of non-phosphorylatable AKT1 suppresses rotavirus replication in a SQSTM1-dependent manner. These findings identify an HSP90-initiated, kinase-independent AKT1 signaling axis that licenses antiviral macroautophagy/autophagy.