title: Generating extracellular amyloid aggregates using E. coli cells.
abstract: Diverse proteins are known to be capable of forming amyloid aggregates, self-seeding fibrillar assemblies that may be biologically functional or pathological. Well-known examples include neurodegenerative disease-associated proteins that misfold as amyloid, fungal prion proteins that can transition to a self-propagating amyloid form and certain bacterial proteins that fold as amyloid at the cell surface and promote biofilm formation. To further explore the diversity of amyloidogenic proteins, generally applicable methods for identifying them are critical. Here we describe a cell-based method for generating amyloid aggregates that relies on the natural ability of Escherichia coli cells to elaborate amyloid fibrils at the cell surface. We use several different yeast prion proteins and the human huntingtin protein to show that protein secretion via this specialized export pathway promotes acquisition of the amyloid fold specifically for proteins that have an inherent amyloid-forming propensity. Furthermore, our findings establish the potential of this E. coli-based system to facilitate the implementation of high-throughput screens for identifying amyloidogenic proteins and modulators of amyloid aggregation.
authors.affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115 USA.
authors.forename: Viknesh
authors.initials: V
authors.lastname: Sivanathan
authors.forename: Ann
authors.initials: A
authors.lastname: Hochschild
mesh_terms: D058227:Amyloidogenic Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D000071058:Huntingtin Protein; D008967:Molecular Biology / Q000379:methods*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D010454:Peptide Termination Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011328:Prions / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D058227:Amyloidogenic Proteins; D001426:Bacterial Proteins; C086055:HTT protein, human; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D010454:Peptide Termination Factors; D011328:Prions; C068068:SUP35 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C077481:Crl protein, Bacteria