Isozymes delta of phosphoinositide-specific phospholipase C

Phospholipase C (PLC, EC 3.1.4.11) is the major starting point in the phosp hatidylinositol pathway, which generates intracellular signals that regulat e protein kinase C and intracellular calcium concentration. To date, three major types of phosphoinositide-specific PLC species named beta, gamma and delta, have been characterized. This article reviews recent studies on isoz ymes delta of PLC. Four such isozymes have been cloned and termed delta(1-4 ). Their structural organization,regulation of activity and the interaction with membrane lipid are considered. The intracellular localization of delt a isozymes and distribution in various tissues are presented. Attention is given to the pathological conditions in which an abnormal protein level of PLC delta or its activity have been observed.