Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of a polyglutamine tract in the huntingtin (htt) protein. To uncover candidate therapeutic targets and networks involved in pathogenesis we integrated gene expression profiling and functional genetic screening to identify genes critical for mutant htt toxicity in yeast. Using mRNA profiling we have identified genes differentially expressed in wild-type yeast in response to mutant htt toxicity, as well as in three toxicity suppressor strains: bna4Delta, mbf1Delta, and ume1Delta. BNA4 encodes the yeast homolog of kynurenine 3-monooxygenase (KMO), a promising drug target for HD. Intriguingly, despite playing diverse cellular roles, these three suppressors share common differentially expressed genes involved in stress response, translation elongation, and mitochondrial transport. We then systematically tested the ability of the differentially expressed genes to suppress mutant htt toxicity when overexpressed, and have thereby identified 12 novel suppressors, including genes that play a role in stress response, Golgi to endosome transport, and rRNA processing. Integrating the mRNA profiling data and the genetic screening data we have generated a robust network which shows enrichment in genes involved in rRNA processing and ribosome biogenesis. Strikingly, these observations implicate dysfunction of translation in the pathology of HD. Recent work has shown that regulation of translation is critical for lifespan extension in Drosophila and that manipulation of this process is protective in Parkinson's disease models. In total these observations suggest that pharmacological manipulation of translation may have therapeutic value in HD.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|