SUMMARY PARAGRAPH for TCO89
TCO89 encodes a nonessential protein that is a component of the TOR complex 1 (TORC1; 1). TORC1 mediates cell growth in response to nutrient availability and cellular stresses by regulating protein synthesis, ribosome biogenesis, autophagy, meiosis, cell cycling, nutrient permease sorting and turnover, and transcriptional activation (3, 4, 5, 6, 7, 8, 3, 9, 10, 11). However, for transcriptional regulation, the presence of Tco89p in TORC1 appears to be dispensable (1). In addition to Tco89p, TORC1 consists of Lst8p, Kog1p, and either Tor1p or Tor2p (4, 1). Mutations in TCO89 are synthetically lethal in combination with tor1 mutations and loss of Tco89p leads to rapamycin hypersensitivity and defects in cell wall integrity (1). Similarly to Tor1p, Tor2p, and Lst8p, Tco89p localizes to the inner side of the plasma membrane, but unlike the other TORC1 components Tco89p can also be found surrounding the vacuolar membrane. This distinct pattern of localization suggests that Tco89p may have an additional function separate from its role as a component of TORC1 (1).
Last updated: 2005-11-03