Functional characteristics of the 14-3-3 proteins. The 14-3-3 proteins form dimers and bind to various proteins in the cell to regulate the function of the target proteins. (A) The target proteins can be structurally modified by binding to the 14-3-3 proteins. The 14-3-3 proteins bind to the target proteins and modulate the activity of the binding protein by blocking or promoting protein-protein interaction with other proteins. In addition, by blocking or opening sites where ubiquitin (ub) is attached to the target protein, 14-3-3 proteins can be involved in protein degradation to regulate stability. (B) The 14-3-3 proteins can regulate the trafficking and localization of binding proteins. (C) The 14-3-3 proteins interact with chaperone proteins such as heat shock proteins (HSP) and have chaperone-like activity themselves. (D) The 14-3-3 proteins have a nuclear localization sequence (NLS), can enter the nucleus, and can bind to transcription factors (TF). Moreover, the 14-3-3 proteins can regulate gene expression by transporting the target protein to the nucleus, or by blocking the target protein from entering the nucleus.
