14-3-3 proteins: key regulators of cell division, signalling and apoptosis

The 14-3-3 proteins constitute a family of conserved proteins present in all eukaryotic organisms so far investigated. These proteins have attracted interest because they are involved in important cellular processes such as signal transduction, cell-cycle control, apoptosis, stress response and malignant transformation and because at least 100 different binding partners for the 14- 3-3 proteins have been reported. Although the exact function of 14-3-3 proteins is still unknown, they are known to (1) act as adaptor molecules stimulating protein-protein interactions, (2) regulate the subcellular localisation of proteins and (3) activate or inhibit enzymes. In this review, we discuss the role of the 14-3-3 proteins in three cellular processes: cell cycle control, signal transduction and apoptosis. These processes are regulated by the 14-3-3 proteins at multiple steps. The 14-3-3 proteins have an overall inhibitory effect on cell cycle progression and apoptosis, whereas in signal transduction they may act as stimulatory or inhibitory factors. (C) 2001 John Wiley & Sons, Inc.