Data for: Sigma-B responses of Bacillus subtilis exposed to different environmental stressors and containing different single RsbR proteins or hybrid fusions of RsbRs

Bacteria use a variety of systems to sense stress and mount an appropriate
response to assure fitness and survival. Bacillus subtilis uses
stressosomes—cytoplasmic multiprotein complexes—to sense environmental
stressors and enact the general stress response by activating the
alternative sigma factor σB. Each stressosome includes 40 RsbR proteins,
representing four paralogous (RsbRA, RsbRB, RsbRC, and RsbRD) putative
stress sensors. Population-level analyses suggested that the RsbR paralogs
are largely redundant, while our prior work using microfluidics-coupled
fluorescence microscopy uncovered differences among the RsbR paralogs’ σB
response profiles with respect to timing and intensity when facing an
identical stressor. We used microfluidics and fluorescence microscopy to
address the question of whether the σB responses mediated by each paralog
differ in the presence of different environmental stressors: can they
distinguish among stressors? Wild-type cells (with all four paralogs) and
RsbRA-only cells activate σB with characteristic transient response timing
irrespective of stressor but show varying response magnitude. However,
cells with other individual RsbR paralogs show distinct timing and
magnitude in their responses to ethanol, salt, oxidative and acid stress,
implying that RsbR proteins can distinguish among stressors. To show this
distinct timing, we quantified time-lapse image series of cells with a
fluorescent σB transcriptional reporter. Representative videos of
time-lapse image series and the results of our quantitation for each RsbR
paralog in each stress condition are included in this dataset. We also
probed the relative importance of each half of each RsbR paralog.
Experiments with hybrid fusion proteins comprising the N-terminal half of
one paralog and the C-terminal half of another argued that the N-terminal
identity influences response magnitude and that determinants in both
halves of RsbRA are important for its stereotypical transient σB response
timing. Time-lapse videos for each hybrid fusion protein and the
corresponding quantification of these data are also included in the
dataset.