Floundering about at cell membranes: a structural view of phospholipid signaling

Structures are now available for the majority of the enzyme families involv ed in the phosphorylation, dephosphorylation and hydrolysis of signaling ph ospholipids. Lipid kinase and phosphatase structures recapitulate catalytic motifs involved in protein phosphorylation and dephosphorylation, whereas cytosolic phospholipase Ap manifests novel catalytic geometry. Structures h ave been determined for most known intracellular phospholipid 'receptor' do mains, both those that bind membrane-embedded phospholipids and those that bind lipid monomers.