Related Experiment Videos
Distribution pattern of Notch3 mutations suggests a gain-of-function mechanism for CADASIL
Christine P Donahue1, Kenneth S Kosik
1Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Insights
Mutations causing cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) likely result in a gain of Notch3 function. This suggests protein misfolding, not signaling deficits, drives the neurological disease.
Area of Science:
- Neuroscience
- Genetics
- Biochemistry
Background:
- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic disorder caused by mutations in the Notch3 gene.
- The precise mechanism underlying CADASIL pathogenesis remains unclear, with hypotheses focusing on Notch3 signaling loss or gain of function.
Purpose of the Study:
- To investigate whether Notch3 mutations associated with CADASIL lead to a loss or gain of function.
- To elucidate the molecular mechanism driving CADASIL development.
Main Methods:
- Bioinformatic analysis of Notch3 paralogs and orthologs.
- Comparative genomic sequence analysis across species to identify conserved regions.
Main Results:
- Conserved sequences suggest Notch3 mutations in CADASIL result in a gain of function.
- This gain of function is linked to protein misfolding and aggregation, not a signaling deficit.
Conclusions:
- CADASIL pathogenesis is more likely driven by Notch3 protein misfolding and aggregation due to a gain of function.
- This finding shifts focus from Notch3 signaling pathways to protein conformational changes in understanding CADASIL.
Abstract:
Mutations in Notch3 cause the syndrome CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). The mechanism by which these mutations result in a CADASIL phenotype has been widely speculated upon. A first step toward understanding a disease mechanism is to learn whether the mutations result in the loss of Notch3 function, in particular, its role in signaling or in the gain of a novel function. Notch3 genomic sequences were analyzed for sites of conservation across species. We present here a bioinformatic analysis of the Notch paralogs and orthologs that suggest that CADASIL mutations result in a gain of function. This finding diminishes the likelihood that a Notch3 signaling deficit is responsible for the phenotype and increases the likelihood that CADASIL joins the growing list of neurological diseases with protein deposits due to misfolding and aggregation.