Huntington's Disease Research Today is a free monthly online journal that collates and summarizes the latest research about Huntington's Disease, including details on genetics, causes, symptoms, treatment.

A genomic screen in yeast implicates kynurenine 3-monooxygenase as a therapeutic target for Huntington disease.

Giorgini F, Guidetti P, Nguyen Q, Bennett SC, Muchowski PJ

Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA.

Huntington disease is a fatal neurodegenerative disorder caused by expansion of a polyglutamine tract in the protein huntingtin (Htt), which leads to its aggregation in nuclear and cytoplasmic inclusion bodies. We recently identified 52 loss-of-function mutations in yeast genes that enhance the toxicity of a mutant Htt fragment. Here we report the results from a genome-wide loss-of-function suppressor screen in which we identified 28 gene deletions that suppress toxicity of a mutant Htt fragment. The suppressors are known or predicted to have roles in vesicle transport, vacuolar degradation, transcription and prion-like aggregation. Among the most potent suppressors was Bna4 (kynurenine 3-monooxygenase), an enzyme in the kynurenine pathway of tryptophan degradation that has been linked directly to the pathophysiology of Huntington disease in humans by a mechanism that may involve reactive oxygen species. This finding is suggestive of a conserved mechanism of polyglutamine toxicity from yeast to humans and identifies new candidate therapeutic targets for the treatment of Huntington disease.

Published 28 April 2005 in Nat Genet, 37(5): 526-31.
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