New insights into the disulfide stress response by the Bacillus subtilis Spx system at a single‐cell level

Abstract

To survive under adverse and fluctuating conditions, bacteria have evolved several mechanisms that sense and respond to stress. In the gram-positive bacterium Bacillus subtilis, the Spx protein (encoded by spxA) is a global transcriptional regulator controlling the expression of large number of genes in response to oxidative stress triggered by thiol-specific agents (Nakano et al., 2003;Rochat et al., 2012).Recent studies have shed light on the role of Spx in responding to other stressors, such as heat shock and cell wall-active compounds, in addition to its well-established role in the disulfide stress response (Rojas-Tapias & Helmann, 2018a;Runde et al., 2014;. Thus, Spx is a versatile and important regulator that mediates the B. subtilis response to various stressors. Spx modulates transcription of target genes by directly interacting with the C-terminal domain of the α-subunit of RNA polymerase (αCTD) (

Impact of Protein Aggregates on Sporulation and Germination of Bacillus subtilis

“…Intracellular PA dynamics were tracked microscopically after inducing PA formation in exponential PS832 amyE::P Hyperspank gfp(Sp)-cI78 EP8 cultures and subsequently monitoring growing cells on IPTG-free nutrient-poor agarose pads to trigger sporulation. As such, and in agreement with recent findings of Matavacas et al (2023) [ 26 ], we first observed that during vegetative growth B. subtilis PAs clearly adhered to the E. coli paradigm of nucleoid-enforced polar localization and asymmetric segregation during vegetative growth ( Figure 2 ). Interestingly, during subsequent sporulation, we could observe that PAs in sporulating cells became highly mobile and sampled more of the cytoplasmic environment, presumably due to an increase in nucleoid-free space as a result of the chromosome condensing into an axial filament during the early stages of sporulation [ 27 ].…”