Inactivation of Drosophila Apaf-1 related killer suppresses formation of polyglutamine aggregates and blocks polyglutamine pathogenesis

Tzu Kang Sang, Chenjian Li, Wencheng Liu, Antony Rodriguez, John M. Abrams, S. Lawrence Zipursky, George R. Jackson

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

Huntington's disease (HD) is caused by expansion of a polyglutamine tract near the N-terminal of huntingtin. Mutant huntingtin forms aggregates in striatum and cortex, where extensive cell death occurs. We used a Drosophila polyglutamine peptide model to assess the role of specific cell death regulators in polyglutamine-induced cell death. Here, we report that polyglutamine-induced cell death was dramatically suppressed in files lacking Dark, the fly homolog of human Apaf-1, a key regulator of apoptosis. Dark appeared to play a role in the accumulation of polyglutamine-containing aggregates. Suppression of cell death, caspase activation and aggregate formation were also observed when mutant huntingtin exon 1 was expressed in homozygous dark mutant animals. Expanded polyglutamine induced a marked increase in expression of Dark, and Dark was observed to colocalize with ubiquitinated protein aggregates. Apaf-1 also was found to colocalize with huntingtin-containing aggregates in a murine model and HD brain, suggesting a common role for Dark/Apaf-1 in polyglutamine pathogenesis in invertebrates, mice and man. These findings suggest that limiting Apaf-1 activity may alleviate both pathological protein aggregation and neuronal cell death in HD.

Original languageEnglish (US)
Pages (from-to)357-372
Number of pages16
JournalHuman molecular genetics
Volume14
Issue number3
DOIs
StatePublished - Feb 1 2005

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Genetics(clinical)

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