title: Metabolic pathways for the degradation of phosphatidic acid in isolated nuclei from cerebellar cells.
abstract: The aim of the present research was to analyse the pathways for phosphatidic acid metabolism in purified nuclei from cerebellar cells. Lipid phosphate phosphatase and diacylglyceride lipase activities were detected in nuclei from cerebellar cells. It was observed that DAGL activity makes up 50% of LPP activity and that PtdOH can also be metabolised to lysophosphatidic acid. With a nuclear protein content of approximately 40 μg, the production of diacylglycerol and monoacylglycerol was linear for 30 min and 5 min, respectively, whereas it increased with PtdOH concentrations of up to 250 μM. LysoPtdOH, sphingosine 1-phosphate and ceramide 1-phosphate, which are alternative substrates for LPP, significantly reduced DAG production from PA. DAG and MAG production increased in the presence of Triton X-100 (1 mM) whereas no modifications were observed in the presence of ionic detergent sodium deoxycholate. Ca²+ and Mg²+ stimulated MAG production without affecting DAG formation whereas fluoride and vanadate inhibited the generation of both products. Specific PtdOH-phospholipase A1 and PtdOH-phospholipase A2 were also detected in nuclei. Our findings constitute the first reported evidence of active PtdOH metabolism involving LPP, DAGL and PtdOH-selective PLA activities in purified nuclei prepared from cerebellar cells.
authors.affiliation: Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C.C. 857, B8000FWB Bahía Blanca, Argentina.
authors.forename: Virginia L
authors.initials: VL
authors.lastname: Gaveglio
authors.forename: Susana J
authors.initials: SJ
authors.lastname: Pasquaré
authors.forename: Norma M
authors.initials: NM
authors.lastname: Giusto
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D002518:Ceramides / Q000378:metabolism; D002531:Cerebellum / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D004075:Diglycerides / Q000096:biosynthesis / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008246:Lysophospholipids / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D053858:Metabolic Networks and Pathways; D050178:Monoglycerides / Q000096:biosynthesis / Q000378:metabolism; D010712:Phosphatidic Acids / Q000378:metabolism*; D054466:Phospholipases A1 / Q000378:metabolism; D054467:Phospholipases A2 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012969:Sodium Fluoride / Q000494:pharmacology; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism; D013997:Time Factors; D014638:Vanadates / Q000494:pharmacology
chemical_list: D002518:Ceramides; D003902:Detergents; D004075:Diglycerides; D008246:Lysophospholipids; D050178:Monoglycerides; D010712:Phosphatidic Acids; C065576:ceramide 1-phosphate; C060506:sphingosine 1-phosphate; D014638:Vanadates; D012969:Sodium Fluoride; D054466:Phospholipases A1; D054467:Phospholipases A2; D008274:Magnesium; D013110:Sphingosine; D002118:Calcium