The Fusion Between Autophagic Vesicles and Lysosomes.

The autophagosome delivers engulfed substrates to the lysosome for degradation via membrane fusion between the autophagosome and the lysosome. The process of membrane fusion is highly conserved in evolution. It is widely accepted that membrane fusion in general is driven by the zippering of the SNARE complex to form a four-helix bundle. Besides SNAREs, other proteins are required to complete fusion efficiently, including tethering proteins, Rab GTPases, and SM proteins (Sec1/SM family proteins). This chapter will summarize the current knowledge of the key machinery involved in autophagosome-lysosome fusion, including autophagic SNAREs, involved ATG proteins, the HOPS complex, Rab GTPase, and other relevant aspects.