The mammalian target of rapamycin (mTOR) was already an established player in cell growth when a discovery late in 2004 stepped up interest in the molecule. TOR was originally found as a target to rapamycin, a drug used to suppress tissue-graft rejection, that was also found to have some tantalizing antitumor effects. The discovery of a rapamycin-insensitive TOR pathway in 2002 in yeast didn't quash the name of the protein, but rather led to the realization that mTOR exists in two distinct multiprotein complexes, mTORC1 and mTORC2.
In the Hot Papers featured here, two labs discovered a mammalian component of mTORC2, the rapamycin-insensitive complex.1,2 David Sabatini's lab at the Massachusetts Institute of Technology found the new binding protein Rictor.1 In a complementary paper, Michael Hall's group at the University of Basel showed mTORC2 to be conserved in yeast and mammals, and to also include Rictor.2 Then, in a follow-up paper, ...
