Daily rhythms of glycerophospholipid synthesis in fibroblast cultures involve differential enzyme contributions

ACOSTA-RODRÍGUEZ VA; MARQUEZ S; SALVADOR GA; PASQUARÉ SJ; GORNÉ LD; GARBARINO PICO E; GIUSTO NM; GUIDO ME

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Lugar: Bethesda, Maryland; Año: 2013 vol. 54 p. 1798 - 1798

ircadian clocks regulate several biochemical processes including lipid metabolism and its disruption leads to severe metabolic disorders. Immortalized cell lines may act as circadian clocks displaying daily variations in [32P]-phospholipid labeling; however, the regulation of glycerophospholipid (GPL) synthesis remains unknown from a chronobiological perspective. In arrested NIH 3T3 cells synchronized with a 2 h-serum shock, we found significant temporal variations in: a) the labeling of total [3H]- GPLs, with lowest levels around 28 and 56 h, and b) the activity of GPL-synthesizing and -remodeling enzymes such as phosphatidate phosphohydrolase 1 (PAP-1) and lysophospholipid acyltransferases (LPLAT), respectively, with clear antiphase profiles. In addition, we investigated the temporal regulation of phosphatidylcholine (PC) biosynthesis. PC is mainly synthesized through the Kennedy pathway being Choline Kinase (ChoK) and CTP: phosphocholine cytidylyltranferase (CCT), key regulatory en