STX17 and infection: 1. HPIV3 infection and overexpression of HPIV3 P protein increase the level of LC3-II and induce autophagosome accumulation.2. HPIV3 P protein binds to SNAP29, thereby preventing the interaction between SNAP29 and STX17.3. HPIV3 suppresses autophagosome–lysosome fusion by the P protein, which disrupts the binding of STX17 to SNAP29.