<prompt> Second messengers, DAG and IP3 are formed fromPhosphatidyl cholinePhosphatidyl ethanolaminePhosphatidyl serinePhosphatidyl inositol  <response>: Phosphatidylinositol Is a Precursor of Second MessengersThe G proteins activate phospholipase C, which hydrolyzes phosphatidylinositol4,5-bisphosphate to produce diacylglycerols and the water-soluble second messenger inositol 1,4,5-triphosphate IP3.Ref: Harper;s Biochemistry; 30th edition; Chapter 54; White Blood Cells 