Beclin-1 is a protein that in humans is encoded by the BECN1 gene. Beclin-1 is also known as autophagy-related gene (Atg) 6. Beclin-1 and its binding partner class III phosphoinositide 3-kinase (PI3K), also named Vps34, which are participates in the regulation of autophagy and has an important role in development, tumorigenesis, and neurodegeneration. Plays a central role in autophagy. Required for the abcission step in cytokinesis. May play a role in antiviral host defense. Protects against infection by a neurovirulent strain of Sindbis virus. Interacts with GOPC and GRID2. Interacts with AMBRA1. Forms a complex with PIK3C3 and PIK3R4 and either UVRAG and KIAA0226/Rubicon, or with ATG14. UVRAG and ATG14 form mutually exclusive complexes through direct competition for BECN1-binding.