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 biosyn thesis 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-su rface proteins, the activity of protein kinases, the metabolism of oth er lipids, and cell growth and viability. This multitude of effects pr obably accounts for the toxicity and carcinogenicity of these mycotoxi ns. Naturally occurring inhibitors of sphingolipid metabolism such as fumonisins are proving to be powerful tools for studying the diverse r oles of sphingolipids in cell regulation and disease.