Metabolism of ceramide phosphorylethanolamine,phosphatidylinositol, phosphatidylserine and phosphatidylglycerol by housefly larvae

Microsome preparations (40,000–90,000 g sediment) fromMusca domestica, housefly, larvae convert exogenous³²P-labeled phosphatidylinositol, phosphatidylserine and phosphatidylglycerol to the respective lysoglycerophosphatides and, ultimately, to the glycerophosphoryl derivatives. These data, combined with previous results, demonstrate that housefly larvae can convert their normal diacylglycerophosphatides to the respective glycerophosphoryl derivatives. Experiments utilizing exogenous³H-labeled,³²P-labeled and¹⁴C-labeled ceramide phosphorylethanolamine demonstrate that particulate preparations from housefly larvae convert ceramide phosphorylethanolamine to ceramide, phosphorylethanolamine, sphingosine and fatty acid. The presence of ceramide phosphorylethanolamine phosphohydrolase and ceramidase activity in housefly larvae is consistent with the conclusion that ceramide phosphorylethanolamine is metabolized to ceramide and phosphorylethanolamine and the ceramide is then hydrolyzed to sphingosine and fatty acid. Thus, metabolism of ceramide phosphorylethanolamine by these insects is analogous to the metabolism of sphingomyelin by mammalian systems. Paper No. 5250 from the Michigan Experiment Station.