Involved in 2 distinct lysosomal degradation pathways: acts as a regulator of autophagy and as a regulator of G-protein coupled receptors turnover. Regulates degradation in lysosomes of a variety of G-protein coupled receptors via its interaction with GPRASP1/GASP1. Homodimer (via coiled-coil domain) (By similarity). Interacts (via coiled-coil domain) with ATG14 (via coiled-coil domain); this interaction is tighter than BECN2 self-association (PubMed:23954414). Interacts with AMBRA1, UVRAG and PIK3C3/VPS34; these interactions are not disrupted by starvation (PubMed:23954414). Does not interact with RUBCN. Interacts (via N-terminus) with GPRASP1/GASP1; the interaction is direct (PubMed:23954414). Expressed in brain, skeletal muscle, placenta, thymus and uterus. Expressed at a lower level in liver, testis, stomach, and 17-day-old embryos. Decreased embryonic viability: embryonic and postnatal survival rates of homozygous mutant mice are markedly lower. Heterozygous knockout mice show defects in autophagy, increased levels of Cnr1 receptor, elevated food intake, and obesity and insulin resistance. Belongs to the beclin family.