A structure-based analysis of huntingtin mutant polyglutamine aggregation and toxicity: evidence for a compact beta-sheet structure

Poirier MA, Jiang H and Ross CA
Source: Hum Mol Genet
Publication Date: (2005)
Issue: 14(6): 765-774
Research Area:
Cells used in publication:
Neuron, cortical, mouse
Species: mouse
Tissue Origin: brain
Nucleofector® I/II/2b
Huntington's disease (HD) arises from an expanded polyglutamine (polyQ) in the N-terminus of the huntingtin (htt) protein. Neuronal degeneration and inclusions containing N-terminal fragments of mutant htt are present in the cortex and striatum of HD brain. Recently, a model of polyQ aggregate structure has been proposed based on studies with synthetic polyQ peptides, and includes an alternating beta-strand/beta-turn structure with seven glutamine residues per beta-strand. We tested this model in the context of the htt exon-1 N-terminal fragment in both mammalian cell culture and in cultured primary cortical neurons. We found our data support this model in the htt protein and provide a better understanding of the structural basis of polyQ aggregation in toxicity in HD.