Two cooperative lipid binding sites within the pleckstrin homology domain are necessary for AKT binding and stabilization to the plasma membrane

Structure. 2025 Jan 2;33(1):181-195.e5. doi: 10.1016/j.str.2024.10.020. Epub 2024 Nov 5.

Abstract

Almost four decades after the identification of the AKT protein and understanding of its role in cancer, barriers remain in the translation of AKT inhibitors for clinical applications. Here, we provide new molecular insight into the first step of AKT activation where AKT binds to the plasma membrane and its orientation is stabilized in a bilayer with lateral heterogeneity (Lo-Ld phase coexistence). We have applied molecular dynamic simulations and molecular and cell biology approaches, and demonstrate that AKT recruitment to the membrane requires a second binding site in the AKT pleckstrin homology (PH) domain that acts cooperatively with the known canonical binding site. Given the precision with which we have identified the protein-lipid interactions, the study offers new directions for AKT-targeted therapy and for testing small molecules to target these specific amino acid-PIP molecular bonds.

Keywords: AKT; PIP lipids; cancer; confocal microscopy; molecular dynamic simulations; oncogene; pleckstrin homology domain; protein-lipid interactions; triple-negative breast cancer.

MeSH terms

  • Binding Sites
  • Cell Membrane* / metabolism
  • Humans
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism
  • Molecular Dynamics Simulation*
  • Pleckstrin Homology Domains*
  • Protein Binding*
  • Protein Stability
  • Proto-Oncogene Proteins c-akt* / chemistry
  • Proto-Oncogene Proteins c-akt* / metabolism

Substances

  • Proto-Oncogene Proteins c-akt
  • Lipid Bilayers