INVESTIGADORES
GARBARINO PICO eduardo
congresos y reuniones científicas
Título:
Diverse glycerolipid synthesizing enzymes contribute to the daily rhythms in phospholipid synthesis.
Autor/es:
ACOSTA-RODRÍGUEZ VA; MARQUEZ S; SALVADOR GA; PASQUARÉ SJ; GORNÉ LD; GARBARINO PICO E; GIUSTO NM; GUIDO ME
Reunión:
Congreso; XLVIII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2012
Resumen:
Circadian clocks regulate biochemical processes including lipid metabolism and their disruption may lead to metabolic disorders such as obesity, diabetes, etc. We have previously shown that the32P-phospholipid synthesis oscillates daily in synchronized fibroblasts; however, little is known about the temporal regulation of glycerophospholipid (GPL) synthesis. We found a circadian change in the incorporation of 3H-glycerol into total GPLs in arrested NIH3T3 cells synchronized with a 2 h-serum shock with lowest levels at 28 and 56 h. A daily variation was also seen in theactivity of GPL-synthesizing and -remodeling enzymes phosphatidate phosphohydrolase 1 (PAP1) and lysophospholipid acyltransferases (LPLAT), respectively with distinct and opposite profiles. We further investigated the temporal regulation of phosphatidylcholine (PC) synthesis through the Kennedy pathway with Choline Kinase (ChoK) and CTP:phosphocholine cytidylyltranferase (CCT) as key enzymes. PC labeling exhibited a daily variation, and maximum levels were accompanied by a brief increase in CCT activity peaking at 6 and 35 h together with theoscillation of ChoK mRNA (a isoform) and activity. Our results demonstrate that synchronized fibroblasts undergo a temporal regulation in the synthesis and remodeling of GPLs and particularlyof PC involving concerted changes in specific enzyme activities and/ormRNAexpression.