. ▁ ▁V ps 3 4 ▁has ▁been ▁shown ▁to ▁interact ▁with ▁V ps 1 5 , ▁a ▁protein ▁kin ase . ▁ ▁V ps 1 5 ▁can ▁activ ate ▁the ▁li pid ▁kin ase ▁activity ▁of ▁V ps 3 4 ▁and ▁interact ▁with ▁Rab 5 , ▁which ▁has ▁been ▁hypoth es ized ▁to ▁rec ruit ▁the ▁V ps 3 4 / 1 5 ▁complex ▁to ▁early ▁end os om es . ▁V ps 1 5 ▁has ▁a ▁my rist o yl ation ▁tag ▁that ▁associ ates ▁the ▁complex ▁with ▁the ▁memb rane . ▁ ▁The ▁V ps 3 4 / 1 5 ▁complex ▁also ▁can ▁interact ▁with ▁Rab 7 . ▁ ▁T ogether , ▁the ▁complex ▁can ▁function ▁at ▁early ▁to ▁late ▁end os om es . ▁ ▁V ps 3 4 ▁has ▁a ▁cal mod ul in ▁binding ▁domain , ▁but ▁its ▁activity ▁has ▁been ▁clearly ▁shown ▁to ▁be ▁calci um - in dependent ▁in ▁vit ro ▁and ▁in ▁v ivo . ▁The ▁functional ▁role ▁of ▁its ▁interactions ▁with ▁cal mod ul in ▁in ▁v ivo ▁are ▁not ▁understood . ▁ ▁V ps 3 4 ▁activity ▁is ▁required ▁for ▁aut oph agy ▁in ▁ye ast , ▁and ▁has ▁been ▁strongly ▁imp licated ▁in ▁this ▁process ▁in ▁m amm als . ▁V ps 3 4 ▁has ▁also ▁been ▁imp licated ▁in ▁am ino ▁acid ▁sens ing . ▁ ▁V ps 3 4 ▁is ▁necessary ▁for ▁m T OR C 1 ▁activity ▁in ▁response ▁to ▁am ino ▁ac ids ▁in ▁cult ured ▁cells