Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2006 Oct 24;103(43):15800-5. Epub 2006 Oct 16.

Global aggregation of newly translated proteins in an Escherichia coli strain deficient of the chaperonin GroEL.

Author information

1
The Scripps Research Institute, La Jolla, CA 92037, USA.

Abstract

In a newly isolated temperature-sensitive lethal Escherichia coli mutant affecting the chaperonin GroEL, we observed wholesale aggregation of newly translated proteins. After temperature shift, transcription, translation, and growth slowed over two to three generations, accompanied by filamentation and accretion (in approximately 2% of cells) of paracrystalline arrays containing mutant chaperonin complex. A biochemically isolated inclusion body fraction contained the collective of abundant proteins of the bacterial cytoplasm as determined by SDS/PAGE and proteolysis/MS analyses. Pulse-chase experiments revealed that newly made proteins, but not preexistent ones, were recruited to this insoluble fraction. Although aggregation of "stringent" GroEL/GroES-dependent substrates may secondarily produce an "avalanche" of aggregation, the observations raise the possibility, supported by in vitro refolding experiments, that the widespread aggregation reflects that GroEL function supports the proper folding of a majority of newly translated polypeptides, not just the limited number indicated by interaction studies and in vitro experiments.

PMID:
17043235
PMCID:
PMC1613232
DOI:
10.1073/pnas.0607534103
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center