Chapter 137 – PX Domains

Publisher Summary The phox (phagocyte oxidase) homology (PX) domains are members of an expanding family of established phosphoinositide-binding domains that includes PH domains, FYVE domains, C2 domains, ENTH domains, and tubby domains. The large differences in structure between these domains suggest that their lipid-binding function arose through the convergent evolution of different structures for the same biological function of lipid binding. Additionally, the PX domain has been shown to participate in a variety of lipid binding-independent functions by acting as a protein–protein interaction module. The examples presented in this chapter show how the understanding of the functional roles that PX domains play in the regulation of their parent proteins has progressed, and it will be important for future work to further elucidate their various mechanisms of action.