Beclin 1 is a 60kDa, BH3-only domain autophagy protein that is essential for the regulation of macroautophagy and the formation of the autophagic vacuole. Through a diverse network of protein interactions, Beclin 1 appears to be a key player in the regulation of a number of critical cellular processes. Specifically, it is a key component of the class III PI3K complex, and interacts with the anti-apoptotic protein, BcL2. Beclin 1 contains 3 identical structural domains comprised of an N-terminal BH3 domain, a central coiled-coil domain and an evolutionarily conserved domain. The expression of Beclin 1 appears to be generally ubiquitous in human and mouse tissues and it is localized predominantly within cytoplasmic structures such as the mitochondria, ER and the perinuclear membrane. Novus offers more than 30 Beclin 1 antibodies for a wide variety of species and applications, which serve as useful tools for autophagy research.