Shenshenbio  Phosphoinositides account for only a small proportion of cellular phospholipids, but have long been known to play an important role in diverse cellular processes, such as cell signaling, the establishment of organelle identity, and the regulation of cytoskeleton and membrane dynamics. Their molecular structure consists of a head group (inositol or other sugar moieties), a middle group (phosphate or another sugar moiety) and two fatty acids attached to the phosphate group. The phosphorylation state of the hydroxyl groups in the head group is directly linked to intracellular signaling cascades. The phosphatidylinositol cycle is one of the major routes involved in the generation of phosphoinositides. The synthesis, degradation, and phosphorylation of phosphoinositides constitute a Diagenox products complicated network that plays an important role in regulating diverse cellular processes. There are seven classes of phosphoinositides with different phosphorylation states of the head group and two to four different types of middle group. The enzymes that mediate the phosphorylation and dephosphorylation of the hydroxyl groups in the head group are responsible for the various functions of phosphoinositides. These enzyme activities determine the localization and activity of many proteins involved in membrane trafficking.