Zinc deficiency is commonly attributed to inadequate absorption of the metal. Instead, we show that body zinc stores in Drosophila melanogaster depend on tryptophan consumption. Hence, a dietary amino acid regulates zinc status of the whole insect-a finding consistent with the widespread requirement of zinc as a protein cofactor. Specifically, the tryptophan metabolite kynurenine is released from insect fat bodies and induces the formation of zinc storage granules in Malpighian tubules, where 3-hydroxykynurenine and xanthurenic acid act as endogenous zinc chelators. Kynurenine functions as a peripheral zinc-regulating hormone and is converted into a 3-hydroxykynurenine-zinc-chloride complex, precipitating within the storage granules. Thus, zinc and the kynurenine pathway-well-known modulators of immunity, blood pressure, aging, and neurodegeneration-are physiologically connected.

Tryptophan regulates Drosophila zinc stores

Barbanente, Alessandra;Vitone, Daniele;Arnesano, Fabio
;
2022-01-01

Abstract

Zinc deficiency is commonly attributed to inadequate absorption of the metal. Instead, we show that body zinc stores in Drosophila melanogaster depend on tryptophan consumption. Hence, a dietary amino acid regulates zinc status of the whole insect-a finding consistent with the widespread requirement of zinc as a protein cofactor. Specifically, the tryptophan metabolite kynurenine is released from insect fat bodies and induces the formation of zinc storage granules in Malpighian tubules, where 3-hydroxykynurenine and xanthurenic acid act as endogenous zinc chelators. Kynurenine functions as a peripheral zinc-regulating hormone and is converted into a 3-hydroxykynurenine-zinc-chloride complex, precipitating within the storage granules. Thus, zinc and the kynurenine pathway-well-known modulators of immunity, blood pressure, aging, and neurodegeneration-are physiologically connected.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11586/430150
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