Interaction between Rho GTPases and 14-3-3 Proteins.

The Rho GTPase family accounts for as many as 20 members. Among them, the archetypes RhoA, Rac1, and Cdc42 have been the most well-characterized. Like all members of the small GTPases superfamily, Rho proteins act as molecular switches to control cellular processes by cycling between active, GTP-bound and inactive, GDP-bound states. The 14-3-3 family proteins comprise seven isoforms. They exist as dimers (homo- or hetero-dimer) in cells. They function by binding to Ser/Thr phosphorylated intracellular proteins, which alters the conformation, activity, and subcellular localization of their binding partners. Both 14-3-3 proteins and Rho GTPases regulate cell cytoskeleton remodeling and cell migration, which suggests a possible interaction between the signaling pathways regulated by these two groups of proteins. Indeed, more and more emerging evidence indicates the mutual regulation of these two signaling pathways. There have been many documented reviews of 14-3-3 protein and Rac1 separately, but there is no review regarding the interaction and mutual regulation of these two groups of proteins. Thus, in this article we thoroughly review all the reported interactions between the signaling pathways regulated by 14-3-3 proteins and Rho GTPases (mostly Rac1).