Proline-rich AKT1 substrate 1 (Akt1s1)

Subunit of mTORC1, which modulates cell growth and survival in response to hormonal and nutrient signals. Growth factor-stimulated mTORC1 activation entails a AKT1-mediated phosphorylation of TSC1-TSC2, which contributes to the activation of this RHEB GTPase that potently activates the protein kinase activity of mTORC1.

Amino acid-signaling into mTORC1 requires its relocalization to the lysosomes mediated by the Ragulator complicated and the Rag GTPases. Activated mTORC1 up-regulates protein synthesis by phosphorylating key regulators of mRNA translation and ribosome synthesis.