Bidirectional lipid inositolphosphotransferase capable of converting phosphatidylinositol (PI) and ceramide to inositol-phosphorylceramide (IPC) and diacylglycerol (DAG) and vice versa. Direction is dependent on the relative concentrations of DAG and ceramide as phosphoinositol acceptors. Does not function strictly as a SM synthase. Essential for viability of the pathogenic bloodstream stage of this human protozoan parasite and, consequently, can be considered as potential drug target (By similarity). Belongs to the sphingomyelin synthase family.