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). Widely expressed in fetal tissues, with the exception of liver. Strongly expressed in adult skeletal muscle and lung. Widely expressed at lower levels in other adult tissues, with weakest expression in liver and spleen. Expressed in extraembryonic tissues and placenta at 11.5 and 18.5 dpc (at protein level). Expression continues throughout gestation and is strong in adult lung (at protein level). 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). Mice are viable and fertile, and show normal placenta and embryonic weights. Belongs to the PHLDA3 family.