Protective role of Engrailed in a Drosophila model of Huntington's disease.
Huntington's disease (HD) is caused by the expansion of the polyglutamine (polyQ) tract in the human Huntingtin (hHtt) protein (polyQ-hHtt). Although this mutation behaves dominantly, htt loss of function may also contribute to HD pathogenesis. Using a Drosophila model of HD, we found that Engrailed (EN), a transcriptional activator of endogenous Drosophila htt (dhtt), is able to prevent aggregation of polyQ-hHtt. To interpret these findings, we tested and identified a protective role of N-terminal fragments of both Drosophila and Human wild-type Htt onto polyQ-hHtt-induced cellular defects. In addition, N-terminal parts of normal hHtt were also able to rescue eye degeneration due to the loss of Drosophila endogenous dhtt function. Thus, our data indicate that Drosophila and Human Htt share biological properties, and confirm a model whereby EN activates endogenous dhtt, which in turn prevents polyQ-hHtt-induced phenotypes. The protective role of wild-type hHtt N-terminal parts, specifically onto polyQ-hHtt-induced cellular toxicity suggests that the HD may be considered as a dominant negative disease rather than solely dominant.
Mugat
Bruno
B
Institute of Human Genetics, UPR1142, CNRS 141, Montpellier Cedex 05, France.
Parmentier
Marie-Laure
ML
Bonneaud
Nathalie
N
Chan
Ho Yin Edwin
HY
Maschat
Florence
F
D000818:Animals; D030801:Animals, Genetically Modified; D047369:Chromatin Immunoprecipitation; D002874:Chromosome Mapping; D029721:Drosophila Proteins; D005123:Eye / Q000473:pathology; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D006816:Huntington Disease / Q000378:metabolism*; D023421:Models, Animal; D010455:Peptides / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
D029721:Drosophila Proteins; C063459:En protein, Drosophila; D018398:Homeodomain Proteins; D010455:Peptides; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D014157:Transcription Factors; C097188:polyglutamine