FYVE-finger proteins – effectors of an inositol lipid

The binding of cytosolic proteins to specific intracellular membranes containing phosphorylated derivatives of phosphatidylinositol (PtdIns) is a common theme in vital cellular processes, such as cytoskeletal function, receptor signalling and membrane trafficking. Recently, several potential effectors of the phosphoinositide 3-kinase product PtdIns 3-phosphate (PtdIns(3)P) have emerged through the observation that a conserved zinc-finger-like domain, the FYVE-finger, binds specifically to this lipid. Here we review current knowledge about the structural basis for the FYVE-PtdIns(3)P interaction, its role in membrane recruitment of proteins and the functions of FYVE-finger proteins in membrane trafficking and other cellular processes.