Researchers discovered that mTORC2 recognizes its key substrate Akt through distant three-dimensional protein structures rather than local amino acid sequences near phosphorylation sites. Using semisynthetic probes to trap the mTORC2::Akt complex, they found that Akt's secondary and tertiary structural elements bind to the mSin1 component of mTORC2, away from the active phosphorylation site. This structural recognition pattern is conserved across at least 18 related substrates. This finding fundamentally changes our understanding of how protein kinases achieve substrate specificity. Most kinases rely on recognizing specific amino acid sequences immediately surrounding the phosphorylation target, but mTORC2 operates through a more sophisticated architectural approach. Given mTORC2's central role in PI3K signaling—a pathway frequently dysregulated in cancer, diabetes, and aging—this structural insight could revolutionize drug development. The discovery may enable design of highly specific mTORC2 inhibitors that target the mSin1-substrate interface rather than competing with ATP at the kinase active site. Such precision therapeutics could potentially modulate aging-related pathways while minimizing off-target effects that plague current mTOR inhibitors.
mTORC2 Uses Protein Structure, Not Sequence, for Akt Phosphorylation
📄 Based on research published in Science (New York, N.Y.)
Read the original paper →For informational, non-clinical use. Synthesized analysis of published research — may contain errors. Not medical advice. Consult original sources and your physician.