We are currently focusing our research on understanding the function of a novel phosphoinositide molecule, PI-5-P, and the enzyme that uses it as substrate, the PI-5-P 4-kinase. PI-5-P levels are normally low but can be induced by extracellular factors, in response to stress or during bacterial invasion. Our goal is to determine how PI-5-P levels are regulated in mammalian cells, to identify its cellular targets and to understand how it affects cellular function in cancer and diabetes.
PI-5-P is the latest and likely the last phospholipid to be identified in the phosphoinositide family. The identification of PI-5-P was an accidental discovery that followed from Dr. Rameh’s observation that a particular phosphoinositide phosphatase generated a lipid with properties that did not fit the profile of other well-characterized phosphoinositides.