Class III PI 3-kinase is a subgroup of the enzyme family, phosphoinositide 3-kinase that share a common protein domain structure, substrate specificity and method of activation.
Vps34 has a calmodulin binding domain, but its activity has been clearly shown to be calcium-independent in vitro and in vivo.
Vps34 activity is required for autophagy in yeast, and has been strongly implicated in this process in mammals.
Vps34 is necessary for mTORC1 activity in response to amino acids in cultured cells, as siRNA knockdown completely inhibits mTORC1 signaling as determined by S6K phosphorylation.
Sequestration of the Vps34 product by FYVE domain overexpression also disrupts mTOR signaling.