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The tau mutation (val337met) disrupts cytoskeletal networks of microtubules
1Department of Neuroscience, Osaka City University Medical School, Abenoku, Osaka, Japan.
Abstract:
The missense point mutation found in the tau gene, which was segregated in a family with frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), has proved to be the causal molecule for widely spread dementia diseases. Here we examined the effects of the tau mutation using confocal analysis. When wild-type tau cDNA was introduced into cells, extensive cell processes and well-developed thick bundles of microtubules were induced. On the other hand, when altered tau cDNA with the mutation (valine337-methionine) was introduced, cell lost processes and microtubule networks resulted in more round cell shape but showed intact mitochondria or endoplasmic reticulum. We conclude that the tau mutation primarily affects the microtubules and resultantly causes the loss of cellular organization and function due to microtubule disruption.
Insights
A tau gene mutation causing frontotemporal dementia with parkinsonism (FTDP-17) disrupts microtubules, leading to cell shape changes and loss of cellular organization. This study reveals the direct impact of tau mutations on microtubule integrity and cellular function.
Area of Science:
- Neuroscience
- Cell Biology
- Genetics
Background:
- Frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) is associated with mutations in the tau gene.
- The tau protein plays a crucial role in microtubule stabilization within neurons.
Purpose of the Study:
- To investigate the cellular effects of a specific tau gene mutation (valine337-methionine) linked to FTDP-17.
- To elucidate the impact of this tau mutation on cellular structure, particularly microtubule networks.
Main Methods:
- Confocal microscopy was used to analyze cells expressing either wild-type or mutated tau cDNA.
- Cellular morphology, including cell processes and microtubule organization, was examined.
Main Results:
- Introduction of wild-type tau cDNA induced extensive cell processes and robust microtubule bundles.
- Cells expressing the mutated tau cDNA exhibited loss of cell processes and disrupted microtubule networks, resulting in a more rounded cell shape.
- Mitochondria and endoplasmic reticulum remained intact in cells with the mutated tau.
Conclusions:
- The tau mutation (valine337-methionine) directly disrupts microtubule organization.
- Microtubule disruption by the tau mutation leads to a loss of cellular organization and function.
- The findings highlight the critical role of tau in maintaining cellular architecture and neuronal health.