Regulator of the DNA damage response (DDR). Part of the TTT complex that is required to stabilize protein levels of the phosphatidylinositol 3-kinase-related protein kinase (PIKK) family proteins. The TTT complex is involved in the cellular resistance to DNA damage stresses, like ionizing radiation (IR), ultraviolet (UV) and mitomycin C (MMC). Together with the TTT complex and HSP90 may participate in the proper folding of newly synthesized PIKKs. Promotes assembly, stabilizes and maintains the activity of mTORC1 and mTORC2 complexes, which regulate cell growth and survival in response to nutrient and hormonal signals (By similarity). Component of the TTT complex composed of TELO2, TTI1 and TTI2. Interacts with ATM, ATR, MTOR, PRKDC, SMG1, TELO2, TRRAP AND TTI2. Component of the mTORC1 and mTORC2 complexes. Interacts with WAC; WAC positively regulates MTOR activity by promoting the assembly of the TTT complex and the RUVBL complex composed of RUVBL1 and RUVBL2 into the TTT-RUVBL complex which leads to the dimerization of the mTORC1 complex and its subsequent activation. Phosphorylated at Ser-823 by CK2 following growth factor deprivation, leading to its subsequent ubiquitination by the SCF(FBXO9) complex. Phosphorylation by CK2 only takes place when TELO2 is bound to mTORC1, not mTORC2; leading to selective ubiquitination of mTORC1-associated protein (By similarity). Ubiquitinated by the SCF(FBXO9) complex following phosphorylation by CK2 in response to growth factor deprivation, leading to its degradation by the proteasome. Only mTORC1-associated protein is ubiquitinated and degraded, leading to selective inactivation of mTORC1 to restrain cell growth and protein translation, while mTORC2 is activated due to the relief of feedback inhibition by mTORC1 (By similarity). Belongs to the tti1 family.