Phosphatidylinositol transfer proteins: Emerging roles in cell proliferation, cell death and survival

The actual cellular functions of the highly homologous small isoforms of the phosphatidylinositol transfer proteins, PI-TPalpha and PI-TPbeta have been studied using many different experimental conditions varying from in vitro experiments with purified proteins and lipid vesicles to investigations in animals. In this review, the very diverse data of these investigations have been collected and joined to propose a model for the cellular functions of PI-TPalpha and PI-TPbeta. The model is based on the suggested roles of PI-TPalpha and PI-TPbeta in various lipid-mediated cellular signaling pathways and leads to the conclusion that both proteins have a regulating function in pathways involved in the proliferation, apoptosis as well as survival of cells.