Metabolic pathways for the degradation of phosphatidic acid in neuronal nuclei of cerebellu.

GAVEGLIO, V.L., .; GIUSTO, N.M; PASQUARÉ S.J.

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2011 vol. 507 p. 271 - 280

0003-9861

The aimof the present research was to analyse the pathways for phosphatidic acidmetabolismin purifiednuclei from cerebellar cells. Lipid phosphate phosphatase and diacylglyceride lipase activities weredetected in nuclei from cerebellar cells. It was observed that DAGL activity makes up 50% of LPP activityand that PtdOH can also be metabolised to lysophosphatidic acid. With a nuclear protein content ofapproximately 40 lg, the production of diacylglycerol and monoacylglycerol was linear for 30 min and5 min, respectively, whereas it increased with PtdOH concentrations of up to 250 lM. LysoPtdOH, sphin-gosine 1-phosphate and ceramide 1-phosphate, which are alternative substrates for LPP, significantlyreduced 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 vana-date inhibited the generation of both products. Specific PtdOH-phospholipase A1 and PtdOH-phospholi-pase A2 were also detected in nuclei. Our findings constitute the first reported evidence of active PtdOHmetabolism involving LPP, DAGL and PtdOH-selective PLA activities in purified nuclei prepared from cer-ebellar cells.