Sphingomyelinase C/phospholipase C <p>This entry represents the proteins sphingomyelinase C (<db_xref db="EC" dbkey="3.1.4.12"/>) and phospholipase C (<db_xref db="EC" dbkey="3.1.4.3"/>). Sphingomyelinase (also known as sphingomyelin phosphodiesterase) is a hydrolase enzyme involved in sphingolipid metabolism, breaking down sphingomyelin to phosphocholine and ceramide [<cite idref="PUB00042945"/>]. However, some of these enzymes act as haemolysins, virulence factors that promotes intracellular proliferation by mediating the disruption of the phagocytic vacuole and the release of bacteria into the host cell cytosol. It may act in concert with the phospholipases PlcA and PlcB and the hemolysin Hly to mediate efficient escape from the vacuole [<cite idref="PUB00044692"/>]. Phospholipase C is a bacterial haemolysin, which are exotoxins that attack blood cell membranes and cause cell rupture. Beta-haemolysin is a phospholipase C with specific activity toward sphingomyelins, and has a high specificity for sphingomyelin [<cite idref="PUB00044693"/>].</p>