p53/tp53-regulated repressor of Akt/akt1 signaling. Represses akt1 by preventing akt1-binding to membrane lipids, thereby inhibiting akt1 translocation to the cellular membrane and activation. Contributes to p53/tp53-dependent apoptosis by repressing akt1 activity. Its direct transcription regulation by p53/tp53 may explain how p53/tp53 can negatively regulate akt1. May act as a tumor suppressor (By similarity). The PH domain binds phosphoinositides with a broad specificity. It competes with the PH domain of akt1 and directly interferes with akt1 binding to phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), preventing akt1 association to membrane lipids and subsequent activation of akt1 signaling (By similarity). Belongs to the PHLDA3 family.