The functional switch of glutamine/asparagine (Q/N)-rich prions and the neurotoxicity of polyQ-expanded proteins involve complex aggregation-prone structural transitions, commonly presumed to be forming beta sheets. By analyzing sequences of interaction partners of these proteins, we discovered a recurrent presence of coiled-coil domains both in the partners and in segments that flank or overlap Q/N-rich and polyQ domains. Since coiled coils can mediate protein interactions and multimerization, we studied their possible involvement in Q/N-rich and polyQ aggregations. Using circular dichroism and chemical crosslinking, we found that Q/N-rich and polyQ peptides form alpha-helical coiled coils in vitro and assemble into multimers. Using structure-guided mutagenesis, we found that coiled-coil domains modulate in vivo properties of two Q/N-rich prions and polyQ-expanded huntingtin. Mutations that disrupt coiled coils impair aggregation and activity, whereas mutations that enhance coiled-coil propensity promote aggregation. These findings support a coiled-coil model for the functional switch of Q/N-rich prions and for the pathogenesis of polyQ-expansion diseases.CI - Copyright (c) 2010 Elsevier Inc. All rights reserved.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|