Functions as an intracellular glutamine sensor that directly activates the TORC1 signaling pathway, to promote cell growth when glutamine is available (PubMed:28993463). May play a role in repressing NPR1 activity independently of TORC1 signaling (PubMed:28993463). Activated by glutamine (By similarity). May also be activated by cysteine (By similarity). Interacts with the TORC1 complex when activated by glutamine or cysteine (By similarity). Interacts with TOR1; glutamine enhances the interaction (By similarity). Interacts with KOG1; glutamine enhances the interaction (By similarity). Interacts with TCO89 (By similarity). Interacts with LST8; glutamine enhances the interaction (By similarity). Interacts with TOR2; glutamine enhances the interaction (By similarity). The FYVE-type zinc finger domain contributes to vacuolar localization. Abnormal activation of TORC1 in nitrogen-replete conditions (glutamine or leucine nitrogen source) (PubMed:28993463). Abnormal TORC1-reactivation following inactivaton by rapamycin (TORC1 signaling-inhibitor) (PubMed:28993463). Sensitive to rapamycin (TORC1 signaling-inhibitor) (PubMed:28993463). Abnormal localization of TOR1 to vacuoles (PubMed:28993463). Localization of GTR1 and GTR2 to vacuoles is normal (PubMed:28993463). Macroautophagy appears normal (PubMed:28993463).