Prion propagation can occur in a prokaryote and requires the ClpB chaperone.
Bottom Line: Here, we demonstrate that E. coli can propagate the Sup35 prion under conditions that do not permit its de novo formation.Prion propagation in yeast requires Hsp104 (a ClpB ortholog), and prior studies have come to conflicting conclusions about ClpB's ability to participate in this process.Our demonstration of ClpB-dependent prion propagation in E. coli suggests that the cytoplasmic milieu in general and a molecular machine in particular are poised to support protein-based heredity in the bacterial domain of life.
Affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States Whitehead Institute for Biomedical Research, Cambridge, United States.Show MeSH
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Mentions: Fluorescence microscopy revealed that cells containing propagated Sup35 NM aggregates exhibited smaller foci emanating from large aggregates typically localized at cell poles, a phenotype distinguished from experimental starter culture cells by the lack of twisted ring structures (Figure 5C). However, we observed one instance of aggregate-positive R1 cells exhibiting twisted ring structures (see Figure 6â€”figure supplement 2C). Whereas we cannot definitively assign the SDS-stable Sup35 NM aggregates detected by filter retention to those structures detected by fluorescence microscopy, we note that fluorescence microscopy of prion-containing yeast cells has also revealed structural diversity (Derkatch et al., 2001; Zhou et al., 2001). Furthermore, cells from aggregate-negative samples invariably exhibited diffuse fluorescence (Figure 5D).10.7554/eLife.02949.012Figure 6.Sup35 NM prion propagation in E. coli requires ClpB.
Affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States Whitehead Institute for Biomedical Research, Cambridge, United States.