Beclin-1 Complex Antibody Sampler Kit

A number of studies have identified distinct complexes involving Beclin-1 and PI3K Kinase Class III with specific roles in autophagy and vesicle trafficking (1,2). These complexes commonly contain Beclin-1, PI3KC3/VSP34, and PIK3R4/VPS15 and function to catalyze the phosphorylation of phosphatidylinositol at the D3 position, producing phosphatidylinositol-3-phosphate. Specificity of PI3KC3 activity is regulated by additional binding partners. Complex 1 contains Atg14 which is required for early stages of autophagosome nucleation (3,4). Complex 2 lacks Atg14, but instead contains UVRAG, and is important for autophagosome maturation and endocytic trafficking (4-6). A third complex, containing both UVRAG and Rubicon, negatively regulates canonical autophagy (7,8). Importantly, this complex containing Rubicon is critical for a related process of LC3-associated phagocytosis (LAP) in which extracellular pathogens binding to cell surface receptors are engulfed by a single membrane phagosome and degraded by the lysosome (9,10). 1.Levine, B. and Kroemer, G. (2019) Cell 176, 11-42. 2.Mei, Y. et al. (2016) Protein Sci 25, 1767-85. 3.Sun, Q. et al. (2008) Proc Natl Acad Sci U S A 105, 19211-6. 4.Itakura, E. et al. (2008) Mol Biol Cell 19, 5360-72. 5.Liang, C. et al. (2006) Nat Cell Biol 8, 688-99. 6.Liang, C. et al. (2008) Nat Cell Biol 10, 776-87. 7.Matsunaga, K. et al. (2009) Nat Cell Biol 11, 385-96. 8.Zhong, Y. et al. (2009) Nat Cell Biol 11, 468-76. 9.Martinez, J. et al. (2015) Nat Cell Biol 17, 893-906. 10.Heckmann, B.L. and Green, D.R. (2019) J Cell Sci 132(5). pii: jcs222984. doi: 10.1242/jcs.222984.