Mutations in String/CDC25 inhibit cell cycle re-entry and neurodegeneration in a Drosophila model of Ataxia telangiectasia
| Autor: | David A. Wassarman, Gerald E. Dodson, Rebeccah J. Katzenberger, Stacey A. Rimkus, Anthony T. Trinh, Randal S. Tibbetts |
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| Rok vydání: | 2008 |
| Předmět: |
DNA Replication
Male Cell cycle checkpoint DNA repair Cdc25 Green Fluorescent Proteins Fluorescent Antibody Technique Apoptosis Cell Cycle Proteins Ataxia Telangiectasia Mutated Proteins Biology Protein Serine-Threonine Kinases Eye Cell Line Animals Genetically Modified Ataxia Telangiectasia Microscopy Electron Transmission Genetics medicine Animals Drosophila Proteins Humans Neurons Tumor Suppressor Proteins Neurodegeneration Cell Cycle Cell cycle medicine.disease Flow Cytometry Cell biology DNA-Binding Proteins Disease Models Animal ELAV Proteins Ataxia-telangiectasia Mutation Nerve Degeneration biology.protein Microscopy Electron Scanning Drosophila Female RNA Interference Protein Tyrosine Phosphatases Ataxia telangiectasia and Rad3 related Developmental Biology Research Paper |
| Zdroj: | Genesdevelopment. 22(9) |
| ISSN: | 0890-9369 |
| Popis: | Mutations in ATM (Ataxia telangiectasia mutated) result in Ataxia telangiectasia (A-T), a disorder characterized by progressive neurodegeneration. Despite advances in understanding how ATM signals cell cycle arrest, DNA repair, and apoptosis in response to DNA damage, it remains unclear why loss of ATM causes degeneration of post-mitotic neurons and why the neurological phenotype of ATM-null individuals varies in severity. To address these issues, we generated a Drosophila model of A-T. RNAi knockdown of ATM in the eye caused progressive degeneration of adult neurons in the absence of exogenously induced DNA damage. Heterozygous mutations in select genes modified the neurodegeneration phenotype, suggesting that genetic background underlies variable neurodegeneration in A-T. The neuroprotective activity of ATM may be negatively regulated by deacetylation since mutations in a protein deacetylase gene, RPD3, suppressed neurodegeneration, and a human homolog of RPD3, histone deacetylase 2, bound ATM and abrogated ATM activation in cell culture. Moreover, knockdown of ATM in post-mitotic neurons caused cell cycle re-entry, and heterozygous mutations in the cell cycle activator gene String/CDC25 inhibited cell cycle re-entry and neurodegeneration. Thus, we hypothesize that ATM performs a cell cycle checkpoint function to protect post-mitotic neurons from degeneration and that cell cycle re-entry causes neurodegeneration in A-T. |
| Databáze: | OpenAIRE |
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