Class III PI3K Vps34: essential roles in autophagy, endocytosis, and heart and liver function.

Mammalian phosphatidylinositol (PI) 3-kinases are a family of proteins that share the ability to phosphorylate phosphoinositides at the 3 position of the inositol ring. By doing so, these kinases produce phospholipid molecules that are involved in various cell signaling pathways, such as insulin signaling and endocytosis. The pathways regulated by PI3-kinases are crucial for maintaining cellular homeostasis and thus must be tightly regulated. Irregular PI3-kinase activity is observed in numerous human pathological conditions, such as diabetes, cancer, and inflammation. One family member, Vps34, is of particular interest because it is the only PI3-kinase identified in yeast and it has been evolutionarily conserved through mammals. Vps34 plays an essential role in the cellular process of autophagy, a process linked to human health and disease. Understanding the precise role of mammalian Vps34 will likely be integral to drug development for various diseases.