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Author Spotlight: Characterizing DNA Replication of Pathogenic Repeats to Uncover Mechanisms of Replication Fork Stalling and Expansion
Published on: September 13, 2024
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The molecular pathogenesis of repeat expansion diseases
Yuzo Fujino1,2, Yoshitaka Nagai1,3
1Department of Neurology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka 589-8511, Japan.
Biochemical Society Transactions
|December 23, 2021
Summary
Expanded repeats in DNA cause genetic diseases, leading to toxic RNA and protein effects. Recent findings suggest a common disease mechanism across different repeat expansion types.
Area of Science:
- Genetics
- Molecular Biology
- Neuroscience
Background:
- Repeat expansion diseases are monogenic disorders, often affecting the nervous system.
- Over 40 such diseases have been identified since the discovery of CGG repeat expansion in the FMR1 gene.
Purpose of the Study:
- To review the major pathogenic mechanisms of repeat expansion diseases.
- To discuss emerging concepts like repeat-associated non-AUG translation and its implications.
- To explore potential therapeutic strategies.
Main Methods:
- Literature review of pathogenic mechanisms in repeat expansion diseases.
- Analysis of toxicity from repeat RNAs and polypeptides.
- Discussion of liquid-liquid phase separation disruption.
Main Results:
- Identified loss-of-function, repeat RNA toxicity (foci, sequestration), and repeat polypeptide toxicity as key mechanisms.
- Highlighted repeat-associated non-AUG translation as a novel pathway for polypeptide toxicity.
- Proposed a common pathogenesis linking coding and non-coding repeat expansion diseases.
Conclusions:
- Repeat expansion diseases share common pathogenic pathways involving RNA and polypeptide toxicity.
- Understanding these mechanisms, including phase separation, is crucial for developing effective therapies.
- Further research into novel translation mechanisms can reveal new therapeutic targets.
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