VPS34

The Beclin 1 protein is a central regulator of autophagy in mammalian cells. Autophagy is an essential process used to maintain cellular homeostasis by degrading and recycling cellular components such as damaged or worn out organelles and macromolecules. Autophagy is also activated in response to cellular stresses such as nutrient starvation or intracellular pathogens and can protect the cell from programmed cell death.

ATG9A is the only essential integral membrane protein involved in autophagy. ATG9A contains six transmembrane domains and initiates the assembly of autophagosomes. The autophagosome is a double-membrane structure that engulfs and eventually degrades cytoplasmic materials such as organelles or macromolecules. Assembly of the autophagosome requires the delivery of lipids and membrane components to initiate and expand the double-membrane pre-autophagosome structure called the isolation membrane.