Fumonisins: Fungal toxins that shed light on sphingolipid function

Fumonisins are sphinganine analogues produced by Fusarium moniliforme and related fungi. They inhibit ceramide synthase and block the biosynthesis of complex sphingolipids, promoting accumulation of sphinganine and sphinganine I-phosphate. Disruption of sphingolipid metabolism by fumonisin B-1 alters cell-cell interactions, the behaviour of cell-surface proteins, the activity of protein kinases, the metabolism of other lipids, and cell growth and viability. This multitude of effects probably accounts for the toxicity and carcinogenicity of these mycotoxins. Naturally occurring inhibitors of sphingolipid metabolism such as fumonisins are proving to be powerful tools for studying the diverse roles of sphingolipids in cell regulation and disease.