title: Conformation sensors that distinguish monomeric proteins from oligomers in live cells.
abstract: Proteins prone to misfolding form large macroscopic deposits in many neurodegenerative diseases. Yet the in situ aggregation kinetics remains poorly understood because of an inability to demarcate precursor oligomers from monomers. We developed a strategy for mapping the localization of soluble oligomers and monomers directly in live cells. Sensors for mutant huntingtin, which forms aggregates in Huntington's disease, were made by introducing a tetracysteine motif into huntingtin that becomes occluded from binding biarsenical fluorophores in oligomers, but not monomers. Up to 70% of the diffusely distributed huntingtin molecules appeared as submicroscopic oligomers in individual neuroblastoma cells expressing mutant huntingtin. We anticipate the sensors to enable insight into cellular mechanisms mediated by oligomers and monomers and for the approach to be adaptable more generally in the study of protein self-association.
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of Melbourne, Bio21 Molecular Science and Biotechnology Institute and Mental Health Research Institute, Parkville VIC 3010, Victoria, Australia.
authors.forename: Yasmin M
authors.initials: YM
authors.lastname: Ramdzan
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Nisbet
authors.forename: Jason
authors.initials: J
authors.lastname: Miller
authors.forename: Steven
authors.initials: S
authors.lastname: Finkbeiner
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Hill
authors.forename: Danny M
authors.initials: DM
authors.lastname: Hatters
mesh_terms: D000818:Animals; D002460:Cell Line; D006801:Humans; D006816:Huntington Disease / Q000378:metabolism*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D011487:Protein Conformation; D017510:Protein Folding; D055503:Protein Multimerization
chemical_list: D009419:Nerve Tissue Proteins