PhosphatidylInositol(3)-phosphate binding protein, activates TORC1; formation of distinct complex with TORC1 is induced by glutamine in dose-dependent manner, suggesting function as putative glutamine sensor in regulation of TORC1; related to human LAPF/phafin1 that regulates lysosomal membrane permeabilization; contains FYVE domain; similar to Fab1p and Vps27p