Measurement of PIP2 metabolism and its relevance for neuronal function

Many plasma membrane proteins have recently been found to require the phospholipid phosphatidylinositol (4,5)-bisphosphate (PIP2) to function. These PIP2-requiring proteins include potassium channels, TRP channels, and several transporters. PIP2 also modulates exocytosis and cell adhesion. Phosphoinsositides are dynamically varying, and we are only beginning to understand the many signals carried by these changes. In order to measure reaction rates for the enzymes involved in PIP2 metabolism, we induced quick PIP2 depletion in individual tsA201 cells by two methods: muscarinic receptor activation (to activate ph…