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

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 on the basis of 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 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.

[1]  D. Moras,et al.  Properties of polyglutamine expansion in vitro and in a cellular model for Huntington's disease. , 1999, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[2]  G P Bates,et al.  Self-assembly of polyglutamine-containing huntingtin fragments into amyloid-like fibrils: implications for Huntington's disease pathology. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[3]  James F. Gusella,et al.  Molecular genetics: Unmasking polyglutamine triggers in neurodegenerative disease , 2000, Nature Reviews Neuroscience.

[4]  D. Tagle,et al.  Mutant Huntingtin Expression in Clonal Striatal Cells: Dissociation of Inclusion Formation and Neuronal Survival by Caspase Inhibition , 1999, The Journal of Neuroscience.

[5]  J. Penney,et al.  Trinucleotide repeat length instability and age of onset in Huntington's disease , 1993, Nature Genetics.

[6]  Michael R. Hayden,et al.  The Influence of Huntingtin Protein Size on Nuclear Localization and Cellular Toxicity , 1998, The Journal of cell biology.

[7]  D. Rubinsztein.  Lessons from animal models of Huntington's disease. , 2002, Trends in genetics : TIG.

[8]  J T Finch,et al.  Glutamine repeats as polar zippers: their possible role in inherited neurodegenerative diseases. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[9]  M. MacDonald,et al.  Huntington's disease. , 1995, Neuromolecular medicine.

[10]  H. Paulson.  Toward an Understanding of Polyglutamine Neurodegeneration , 2000, Brain pathology.

[11]  C A Ross,et al.  Truncated N-terminal fragments of huntingtin with expanded glutamine repeats form nuclear and cytoplasmic aggregates in cell culture. , 1998, Human molecular genetics.

[12]  P. Tortora,et al.  Temperature-dependent, irreversible formation of amyloid fibrils by a soluble human ataxin-3 carrying a moderately expanded polyglutamine stretch (Q36). , 2003, Biochemistry.

[13]  K. Lindenberg,et al.  Proteases acting on mutant huntingtin generate cleaved products that differentially build up cytoplasmic and nuclear inclusions. , 2002, Molecular cell.

[14]  D. Borchelt,et al.  Intranuclear inclusions and neuritic aggregates in transgenic mice expressing a mutant N-terminal fragment of huntingtin. , 1999, Human molecular genetics.

[15]  D. Rubinsztein,et al.  Wild type huntingtin reduces the cellular toxicity of mutant huntingtin in mammalian cell models of Huntington's disease , 2001, Journal of medical genetics.

[16]  A. Hackam,et al.  Inhibiting Caspase Cleavage of Huntingtin Reduces Toxicity and Aggregate Formation in Neuronal and Nonneuronal Cells* , 2000, The Journal of Biological Chemistry.

[17]  Christopher A. Ross,et al.  Huntingtin Spheroids and Protofibrils as Precursors in Polyglutamine Fibrilization* , 2002, The Journal of Biological Chemistry.

[18]  Claire-Anne Gutekunst,et al.  A YAC Mouse Model for Huntington’s Disease with Full-Length Mutant Huntingtin, Cytoplasmic Toxicity, and Selective Striatal Neurodegeneration , 1999, Neuron.

[19]  R. Wetzel,et al.  Mutational analysis of the structural organization of polyglutamine aggregates , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[20]  W. Strittmatter,et al.  Disruption of the toxic conformation of the expanded polyglutamine stretch leads to suppression of aggregate formation and cytotoxicity. , 2004, Biochemical and biophysical research communications.

[21]  R. Wetzel,et al.  Inhibition of polyglutamine aggregate cytotoxicity by a structure‐based elongation inhibitor , 2004, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[22]  S. Hersch,et al.  Huntingtin aggregates may not predict neuronal death in Huntington's disease , 1999 .

[23]  Harry T Orr,et al.  Mutation of the E6-AP Ubiquitin Ligase Reduces Nuclear Inclusion Frequency While Accelerating Polyglutamine-Induced Pathology in SCA1 Mice , 1999, Neuron.

[24]  S. W. Davies,et al.  Intranuclear Neuronal Inclusions in Huntington's Disease and Dentatorubral and Pallidoluysian Atrophy: Correlation between the Density of Inclusions andIT15CAG Triplet Repeat Length , 1998, Neurobiology of Disease.

[25]  R. Mott,et al.  Instability of highly expanded CAG repeats in mice transgenic for the Huntington's disease mutation , 1997, Nature Genetics.

[26]  S. W. Davies,et al.  Aggregation of huntingtin in neuronal intranuclear inclusions and dystrophic neurites in brain. , 1997, Science.

[27]  Mark Turmaine,et al.  Formation of Neuronal Intranuclear Inclusions Underlies the Neurological Dysfunction in Mice Transgenic for the HD Mutation , 1997, Cell.

[28]  A. Hackam,et al.  Length of huntingtin and its polyglutamine tract influences localization and frequency of intracellular aggregates , 1998, Nature Genetics.

[29]  Hans Lehrach,et al.  Huntingtin-Encoded Polyglutamine Expansions Form Amyloid-like Protein Aggregates In Vitro and In Vivo , 1997, Cell.

[30]  M. Beal,et al.  Experimental therapeutics in transgenic mouse models of Huntington's disease , 2004, Nature Reviews Neuroscience.

[31]  Junying Yuan,et al.  Pivotal role of oligomerization in expanded polyglutamine neurodegenerative disorders , 2003, Nature.

[32]  P. Loll,et al.  An expanded glutamine repeat destabilizes native ataxin-3 structure and mediates formation of parallel β-fibrils , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[33]  Lisa Garrett,et al.  Behavioural abnormalities and selective neuronal loss in HD transgenic mice expressing mutated full-length HD cDNA , 1998, Nature Genetics.

[34]  C. Ross,et al.  Polyglutamine Repeat Length-Dependent Proteolysis of Huntingtin , 2002, Neurobiology of Disease.

[35]  C. Ross.  Huntington's Disease New Paths to Pathogenesis , 2004, Cell.

[36]  S. W. Davies,et al.  Exon 1 of the HD Gene with an Expanded CAG Repeat Is Sufficient to Cause a Progressive Neurological Phenotype in Transgenic Mice , 1996, Cell.

[37]  M. Hayden,et al.  Inhibition of Calpain Cleavage of Huntingtin Reduces Toxicity , 2004, Journal of Biological Chemistry.

[38]  Steven Finkbeiner,et al.  Huntingtin Acts in the Nucleus to Induce Apoptosis but Death Does Not Correlate with the Formation of Intranuclear Inclusions , 1998, Cell.

[39]  C. Ross,et al.  Cell death triggered by polyglutamine-expanded huntingtin in a neuronal cell line is associated with degradation of CREB-binding protein. , 2003, Human molecular genetics.

[40]  R. Wetzel,et al.  Aggregated polyglutamine peptides delivered to nuclei are toxic to mammalian cells. , 2002, Human molecular genetics.

[41]  H. Zoghbi,et al.  Glutamine repeats and neurodegeneration. , 2000, Annual review of neuroscience.

[42]  Christopher A Ross,et al.  Polyglutamine Pathogenesis Emergence of Unifying Mechanisms for Huntington's Disease and Related Disorders , 2002, Neuron.

[43]  C. Ross,et al.  Polyglutamine fibrillogenesis: The pathway unfolds , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[44]  S. Hersch,et al.  Huntington aggregates may not predict neuronal death in Huntington's disease. , 1999, Annals of neurology.

[45]  T. Dawson,et al.  Manganese Superoxide Dismutase Protects nNOS Neurons from NMDA and Nitric Oxide-Mediated Neurotoxicity , 1998, The Journal of Neuroscience.

[46]  C A Ross,et al.  Correlation between the onset age of Huntington's disease and length of the trinucleotide repeat in IT-15. , 1993, Human molecular genetics.