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Updated: Aug 15, 2026
In Vivo Forward Genetic Screen to Identify Novel Neuroprotective Genes in Drosophila melanogaster
Published on: July 11, 2019
Gain-of-function screen identifies a role of the Sec61alpha translocon in Drosophila postmitotic neurotoxicity
Hirotaka Kanuka1, Tetsuo Hiratou, Tatsushi Igaki
1Department of Genetics, Graduate School of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
Abstract:
To elucidate the intrinsic mechanisms of neurotoxicity induction, including those underlying neural cell death and neurodegeneration, we developed a gain-of-function screen for gene products causing neural cell loss. To identify novel genes with a cell-death-related function in neurons, we screened 4,964 Drosophila GS lines, in which one or two genes from much of the Drosophila genome can be overexpressed. Approximately 0.68% of the GS lines produced phenotypes involving a loss of postmitotic neurons. Of these, we identified and characterized the endd2 gene, which encodes the Drosophila ortholog of Sec61alpha (DSec61alpha), an endoplasmic reticulum protein with protein translocation activity. Ectopic expression of DSec61alpha caused neural cell death accompanied by the accumulation of ubiquitinated proteins, which was mediated by DSec61alpha's translocon activity. This supported our previous observation that the DSec61alpha translocon contributes to expanded polyglutamine-mediated neuronal toxicity, which is also associated with ubiquitinated protein accumulation. These data suggest that the translocon may be a novel component of neural cell death and degeneration pathways. Our approach can be used to identify potential neurotoxic factors within the whole genome, which will increase our understanding of the molecular mechanisms of various types of cell death, including those associated with human neurodegenerative diseases.
Insights
Researchers identified endd2 (DSec61alpha), an endoplasmic reticulum protein, as a cause of neural cell death. Its translocon activity contributes to neurodegeneration and protein accumulation, offering insights into human diseases.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- Understanding neurotoxicity mechanisms is crucial for addressing neurodegenerative diseases.
- Identifying genes involved in neural cell death is key to elucidating these mechanisms.
Purpose of the Study:
- To identify novel genes causing neural cell loss using a gain-of-function screen.
- To investigate the role of identified genes, specifically endd2 (DSec61alpha), in neural cell death and neurodegeneration.
Main Methods:
- Conducted a large-scale gain-of-function screen of 4,964 Drosophila GS lines.
- Overexpressed gene products to identify those causing postmitotic neuron loss.
- Characterized the function of the identified endd2 gene and its protein product, DSec61alpha.
Main Results:
- Approximately 0.68% of screened lines exhibited neuronal loss phenotypes.
- Identified and characterized endd2, encoding Drosophila Sec61alpha (DSec61alpha), an endoplasmic reticulum protein.
- Ectopic DSec61alpha expression induced neural cell death via its translocon activity, leading to ubiquitinated protein accumulation.
Conclusions:
- The endoplasmic reticulum translocon, via DSec61alpha, is implicated as a novel factor in neural cell death and degeneration pathways.
- DSec61alpha's role in neurotoxicity is linked to accumulated ubiquitinated proteins, consistent with polyglutamine-mediated toxicity.
- The screening approach provides a platform for identifying genome-wide neurotoxic factors and understanding cell death mechanisms in human diseases.
