In:
Genes & Development, Cold Spring Harbor Laboratory, Vol. 20, No. 13 ( 2006-07-01), p. 1776-1789
Abstract:
The heat-shock response (HSR), a universal cellular response to heat, is crucial for cellular adaptation. In Escherichia coli , the HSR is mediated by the alternative σ factor, σ 32 . To determine its role, we used genome-wide expression analysis and promoter validation to identify genes directly regulated by σ 32 and screened ORF overexpression libraries to identify σ 32 inducers. We triple the number of genes validated to be transcribed by σ 32 and provide new insights into the cellular role of this response. Our work indicates that the response is propagated as the regulon encodes numerous global transcriptional regulators, reveals that σ 70 holoenzyme initiates from 12% of σ 32 promoters, which has important implications for global transcriptional wiring, and identifies a new role for the response in protein homeostasis, that of protecting complex proteins. Finally, this study suggests that the response protects the cell membrane and responds to its status: Fully 25% of σ 32 regulon members reside in the membrane and alter its functionality; moreover, a disproportionate fraction of overexpressed proteins that induce the response are membrane localized. The intimate connection of the response to the membrane rationalizes why a major regulator of the response resides in that cellular compartment.
Type of Medium:
Online Resource
ISSN:
0890-9369
,
1549-5477
Language:
English
Publisher:
Cold Spring Harbor Laboratory
Publication Date:
2006
detail.hit.zdb_id:
1467414-2
SSG:
12
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