Protein fragments disrupt nerve-cell signalling in ataxia models
A peer-reviewed study traced how cleavage of a gene-regulating protein disturbed a signalling pathway in models of spinocerebellar ataxia type 17. Cell experiments, patient-derived neurons and animal models connected the protein fragments with reduced AMOT, another protein involved in neural function. Human-cell comparisons involved one patient and one control; the work investigates disease mechanisms rather than a clinical treatment.
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A gene-regulating protein broke into disruptive fragments
A laboratory investigation of spinocerebellar ataxia type 17 connected protein fragmentation with disturbed nerve-cell signalling. This rare inherited degenerative disease involves expanded glutamine repeats in TATA-box-binding protein, or TBP, which helps initiate gene transcription. In the peer-reviewed Nature Communications study, calcium-activated enzymes called calpains cut TBP. Its fragments accumulated in different cellular compartments, and some increased calpain activity further. The experiments examined a molecular disease process.[1]
Reduced AMOT appeared across experimental models
Protein and gene-activity measurements drew attention to angiomotin, known as AMOT, a protein linked to neuronal function and signalling through Yes-associated protein 1, or YAP1. Patient-derived neurons displayed greater calpain activity, fragmented TBP and reduced AMOT. Human-cell comparisons used material from one patient and one matched unaffected person, limiting population-wide conclusions. Cerebellar tissue from rats modelling the disease also showed reductions in proteins associated with this pathway.[1]
Embryo experiments connected the pathway with movement
In zebrafish embryos, reducing amot function affected motor-neuron numbers and swimming responses to touch. Introducing human AMOT reversed some of those effects. These developmental experiments added a functional connection to the cellular findings. The researchers considered altered gene expression, protein cleavage and capture within aggregates as complementary explanations for AMOT depletion. Their study combines cell and animal models, with no clinical trial establishing a treatment for people with ataxia.[1]
