title: Nuclear sphingomyelin-synthase and protein kinase C delta in melanoma cells.
abstract: The aim of this research is to study the influence of protein kinase C delta on the nuclear phospholipids metabolism. Murine and human melanoma cells, in which overexpression of protein kinase delta was induced, were used. After purification of the nuclei, the phosphatidylcholine-dependent phospholipase C, sphingomyelin-synthase, and sphingomyelinase activities were measured. The results showed that the nuclear sphingomyelin-synthase activity increased and sphingomyelinase activity decreased in the protein kinase C delta overexpressive cells with respect to the controls. As a consequence, the ceramide pool decreased and diacylglycerol pool increased; this effect was not due to the phosphatidylcholine-dependent phospholipase C activity that did not change. The inhibition of sphingomyelinase could be due to protein kinase C delta as well as to existence of a sort of nuclear self-regulation between sphingomyelin-synthase and sphingomyelinase. The possible role of nuclear sphingomyelin-synthase in cell proliferation is discussed.
authors.affiliation: Department of Clinical and Experimental Medicine, Physiopathology, Policlinico Monteluce, University of Perugia, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Albi
authors.forename: Caterina A M
authors.initials: CA
authors.lastname: La Porta
authors.forename: Samuela
authors.initials: S
authors.lastname: Cataldi
authors.forename: Mariapia Viola
authors.initials: MV
authors.lastname: Magni
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000201:enzymology* / Q000378:metabolism; D049109:Cell Proliferation; D002518:Ceramides / Q000378:metabolism; D006801:Humans; D008545:Melanoma / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D010713:Phosphatidylcholines / Q000378:metabolism; D011493:Protein Kinase C / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D051745:Protein Kinase C-delta; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D014162:Transfection; D017855:Transferases (Other Substituted Phosphate Groups) / Q000096:biosynthesis / Q000502:physiology*; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D002518:Ceramides; D010713:Phosphatidylcholines; C497259:Prkcd protein, mouse; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D017855:Transferases (Other Substituted Phosphate Groups); C070186:phosphatidylcholine-ceramide phosphocholine transferase; D010738:Type C Phospholipases; D013108:Sphingomyelin Phosphodiesterase