Fig. 3.

Schematic presentation of sphingolipids metabolism pathways and consequences of S1P lyase deficiency, and also presents the site of AAL-toxin/fumonisin inhibition. S1P lyase paucity leads to enhance of cellular S1P and sphingosine (to a smaller extent). Thus, de novo sphingolipid biosynthesis (blue arrows) is decreased may be up-regulation of Orm1/3 expression. At the same time, the recycling pathway (gray arrows) is elevated. SMS: sphingomyelin synthases, SMase: sphingomyelinases, CS: ceramide synthases, CDase: ceramidases, SPP: S1P phosphatase, SK: sphingosine kinases.