A genomewide RNA interference screen for modifiers of aggregates formation by mutant Huntingtin in Drosophila.
Protein aggregates are a common pathological feature of most neurodegenerative diseases (NDs). Understanding their formation and regulation will help clarify their controversial roles in disease pathogenesis. To date, there have been few systematic studies of aggregates formation in Drosophila, a model organism that has been applied extensively in modeling NDs and screening for toxicity modifiers. We generated transgenic fly lines that express enhanced-GFP-tagged mutant Huntingtin (Htt) fragments with different lengths of polyglutamine (polyQ) tract and showed that these Htt mutants develop protein aggregates in a polyQ-length- and age-dependent manner in Drosophila. To identify central regulators of protein aggregation, we further generated stable Drosophila cell lines expressing these Htt mutants and also established a cell-based quantitative assay that allows automated measurement of aggregates within cells. We then performed a genomewide RNA interference screen for regulators of mutant Htt aggregation and isolated 126 genes involved in diverse cellular processes. Interestingly, although our screen focused only on mutant Htt aggregation, several of the identified candidates were known previously as toxicity modifiers of NDs. Moreover, modulating the in vivo activity of hsp110 (CG6603) or tra1, two hits from the screen, affects neurodegeneration in a dose-dependent manner in a Drosophila model of Huntington's disease. Thus, other aggregates regulators isolated in our screen may identify additional genes involved in the protein-folding pathway and neurotoxicity.
Zhang
Sheng
S
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA. sheng.zhang@uth.tmc.edu
Binari
Richard
R
Zhou
Rui
R
Perrimon
Norbert
N
D000367:Age Factors; D000818:Animals; D029721:Drosophila Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D049750:Genome, Insect / Q000235:genetics; D023281:Genomics; D050957:HSP110 Heat-Shock Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D057166:High-Throughput Screening Assays; D006801:Humans; D000071058:Huntingtin Protein; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010455:Peptides / Q000235:genetics; D055503:Protein Multimerization / Q000235:genetics*; D020836:Protein Structure, Quaternary; D034622:RNA Interference; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism
D029721:Drosophila Proteins; D050957:HSP110 Heat-Shock Proteins; C542005:Htt protein, Drosophila; D000071058:Huntingtin Protein; D008869:Microtubule-Associated Proteins; D050505:Mutant Proteins; C511055:NIPPED-A protein, Drosophila; D010455:Peptides; D014157:Transcription Factors; C097188:polyglutamine