Cholesterol and PI(4,5)P2 in Vital Biological Functions: From Coexistence to Crosstalk

Cholesterol is an essential component of the plasma membrane. Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), although a minor phospholipid, is the most abundant membrane phosphoinositide. Both lipids play key roles in a variety of cellular functions including as signalling molecules and major regulators of protein function. Studies on these important lipids have traditionally focused on the effect of each lipid individually. Accumulating evidence indicates, however, that these lipids may cross-regulate each other?s levels. Furthermore, it is becoming evident that cholesterol and PI(4,5)P2 can act together to modulate protein function and biological processes. This book provides an overview of cellular functions and molecular mechanisms in which cholesterol and PI(4,5)P2 functions extend from parallel existence to crosstalk. It includes four sections. The first section introduces the reader to cholesterol and PI(4,5)P2. The second section demonstrates the mutual influence of these two critical lipids on their levels.