Phosphatidylinositol 3,5-bisphosphate: regulation of cellular events in space and time

Phosphorylated phosphatidylinositol lipids are crucial for most eukaryotes and have diverse cellular functions. The low-abundance signalling lipid phosphatidylinositol 3,5-bisphosphate [PI(3,5)P₂] is critical for cellular homoeostasis and adaptation to stimuli. A large complex of proteins that includes the lipid kinase Fab1–PIKfyve, dynamically regulates the levels of PI(3,5)P₂. Deficiencies in PI(3,5)P₂ are linked to some human diseases, especially those of the nervous system. Future studies will probably determine new, undiscovered regulatory roles of PI(3,5)P₂, as well as uncover mechanistic insights into how PI(3,5)P₂ contributes to normal human physiology.