Table 10. Mechanistic Genes of the Phosphatidylinositol Signaling System.

Up-Regulated Mechanistic Genes
PLCD1	phospholipase C, delta 1	Encodes phosphoinositide-specific phospholipase C that acts as a signal transducer and has diverse biological functions including roles in inflammation, cell growth, signaling and death and maintenance of membrane phospholipids
PLCB4	phospholipase C, beta 4	The protein encoded by this gene catalyzes the formation of inositol 1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. This reaction uses calcium as a cofactor and plays an important role in the intracellular transduction of many extracellular signals
INPP4A	inositol polyphosphate-4-phosphatase, type I	Encodes an Mg++ independent enzyme that hydrolyzes the 4-position phosphate from the inositol ring of phosphatidylinositol 3,4-bisphosphate, inositol 1,3,4-trisphosphate, and inositol 3,4-bisphosphate. This reaction uses calcium as a cofactor and plays an important role in the intracellular transduction of many extracellular signals similar to PLCD1
ITPR2	inositol 1,4,5-trisphosphate receptor, type 2	Encode receptors for inositol 1,4,5-trisphosphate, a second messenger that mediates the release of intracellular calcium
ITPR3	inositol 1,4,5-trisphosphate receptor, type 3	Encode receptors for inositol 1,4,5-trisphosphate, a second messenger that mediates the release of intracellular calcium
Down-Regulated Mechanistic Genes
CALM2	calmodulin 2	The protein encoded by CALM2 mediates the control of a large number of enzymes and other proteins by Ca++ and is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis