Component of TORC2, which regulates multiple cellular processes to control cell growth in response to environmental signals. TORC2 is required for cell survival under various stress conditions. TORC2 positively controls G1 cell-cycle arrest, sexual development and amino acid uptake. Positively regulates amino acid uptake through the control of expression of amino acid permeases. The target of rapamycin complex 2 (TORC2) is composed of at least bit61, pop3/wat1, sin1, ste20 and tor1 (PubMed:18076573, PubMed:18257517). Interacts with the sty1 MAP kinase (PubMed:10428959). Phosphorylated; under environmental stress. Either Ser-61 or Ser-62 and Ser-298, Ser-299 or Ser-301 are phosphorylated as well (PubMed:18076573). Belongs to the SIN1 family.