Implication of sphingolipid metabolism in the stability of the Golgi apparatus

We examined the effects of short chain and long chain ceramides on the stab ility of the Golgi apparatus. Short chain ceramides, C-2- and C-6-ceramides , blocked brefeldin A-induced Golgi disassembly without affecting the rapid release of Golgi coat proteins, whereas they did not inhibit brefeldin A-i nduced tubulation of endosomes, Both short chain ceramides also retarded Go lgi disassembly induced by nordihydroguaiaretic acid and nocodazole, sugges ting that they stabilize the Golgi apparatus, In contrast to short chain ce ramides, natural long chain ceramides, when incorporated into cells or form ed within cells upon treatment with sphingomyelinase or metabolic inhibitor s, enhanced brefeldin A-induced Golgi disassembly. These results suggest th at sphingolipid metabolism is implicated in the stability of the Golgi appa ratus.