Glycerol 3-P-acyltransferase 2 is expressed in testis and involved in cellular proliferation

CATTANEO, E.R.; PELLON-MAISON, M.; COLEMAN, R.A.; GONZALEZ-BARO, M.R.

Villa Carlos Paz, Cordoba

Congreso; XLIV Reunión Anual de SAIB; 2008

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

GLYCEROL-3-P-ACYLTRANSFERASE 2 IS EXPRESSED IN TESTIS AND INVOLVED IN CELLULAR PROLIFERATIONCattaneo ER; Pellon Maison M; Coleman RA; Gonzalez Baro MRINIBIOLP- CCT La Plata- CONICET-UNLP. 60 y 120- La PlataE-mail: ecattaneo@biol.unlp.edu.ar Glycerol-3-phosphate acyltransferase (GPAT) catalyzes the first and committed step in de novo glycerolipid synthesis. In mammals, several isoforms have been described with different cellular localization and kinetic properties. The mitochondrial isoform GPAT2 is highly expressed in rat testis and has no preference for saturated acyl-CoA substrates, so we hypothesized that it would be involved in the synthesis of triacylglycerols (TAG) rich in unsaturated fatty acids, required for the proper testicular function. Northern blot analysis showed that GPAT2 mRNA is expressed in seminiferous tubules, specifically in germ-line cells. The expression increases with age, and it is consistent with spermatogenesis.Transient GPAT2 overexpression in CHOK1 cells increased the TAG content respecting GPAT1-overexpressing and control cells. Lipid droplets were larger and similar in number. CHO-K1 cell stably overexpressing GPAT2 showed increased proliferation compared to GPAT1 and control cells. Crystal violet proliferation assays showed that, after 65 hr, cell number was ~30% higher in GPAT2-overexpressing cells.Our results indicate that GPAT2 is involved in TAG synthesis related to spermatic cells, and some metabolite/s derived from its activity may be involved in the testis’ processes of cellular proliferation.