Beclin 1 participates in the regulation of autophagy and has an important role in development, tumorigenesis, and neurodegeneration. Beclin 1 can complement defects in yeast autophagy caused by loss of Apg6 and can also stimulate autophagy when overexpressed in mammalian cells. Autophagy is a catabolic process for the autophagosomic-lysosomal degradation of proteins activated in response to nutrient deprivation and in neurodegenerative conditions . One of the proteins critical to this process is Beclin 1, the mammalian orthologue of the yeast autophagy protein Apg6/Vps30. Mammalian Beclin 1 was originally isolated in a yeast two-hybrid screen for Bcl-2 interacting proteins and has been shown to interact with Bcl-2 and Bcl-xL, but not with Bax or Bak.