Fig. 2. Reported sites of action of PTEN. Extracellular interactions trigger signaling from integrins and growth factor receptors. The major function of PTEN appears to be downregulation of the PI 3-kinase product PtdIns(3,4,5)P3, which regulates Akt and complex downstream pathways affecting cell growth, survival and migration. In addition, PTEN has weak protein tyrosine phosphatase activity, which may target focal adhesion kinase (FAK) and Shc, and thereby modulate other complex pathways. The phosphatase domain of PTEN (red) dephosphorylates and downregulates (red lines) substrate molecules.
