Model of the Akt–TOR signaling transduction network <i>in vivo</i>.

<p>Under wild-type conditions, negative feedback to the PI3K/Akt signaling branch is mediated by TORC1 (containing TOR, Lst8 and Raptor), independently of S6K. Under conditions of high TORC1 signaling load, induced e.g. by mutations in <i>tsc1</i> or <i>tsc2</i>, negative feedback becomes S6K dependent. See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000990#s3" target="_blank">discussion</a> for details.</p>