, ▁as ▁si R NA ▁knock down ▁completely ▁in hib its ▁m T OR C 1 ▁signal ing ▁as ▁determined ▁by ▁S 6 K ▁ph osph ory lation . ▁ ▁Se quest r ation ▁of ▁the ▁V ps 3 4 ▁product ▁by ▁F Y VE ▁domain ▁over expression ▁also ▁dis rupt s ▁m T OR ▁signal ing . ▁However , ▁gen etic ▁ab lation ▁of ▁V ps 3 4 ▁in ▁D ros oph ila ▁does ▁not ▁affect ▁d T OR C 1 ▁signal ing . ▁Thus , ▁the ▁role ▁of ▁V ps 3 4 ▁in ▁am ino ▁acid ▁signal ing ▁to ▁m T OR C 1 ▁remains ▁controvers ial . ▁ ▁One ▁recent ▁paper ▁suggested ▁that ▁the ▁human ▁orth olog ▁is ▁reg ulated ▁by ▁int rac ell ular ▁calci um , ▁but ▁this ▁was ▁later ▁shown ▁to ▁be ▁due ▁to ▁a ▁calci um - in dependent ▁in hib ition ▁of ▁V ps 3 4 ▁by ▁E G TA , ▁an ▁effect ▁not ▁seen ▁with ▁other ▁calci um ▁ch el ators . ▁ ▁The ▁mechan isms ▁that ▁reg ulate ▁V ps 3 4 ▁activity ▁in ▁m amm al ian ▁cells ▁are ▁not ▁yet ▁understood . ▁ ▁See ▁also ▁ ▁ph osph o inos it ide ▁ 3 - kin ase ▁ ▁F Y VE ▁domain ▁ ▁P X ▁domain ▁ ▁References ▁ ▁Liter ature ▁▁ ▁Stein ▁RC ( ▁ 2 0 0 1 ) ▁Pro spect s ▁for ▁ph osph o inos it ide ▁ 3 - kin ase ▁in hib ition ▁as ▁a