Dataset Information

The activity of ?V, an extracytoplasmic function ? factor of Bacillus subtilis, is controlled by regulated proteolysis of the anti-? factor RsiV.

ABSTRACT: During growth in the environment, bacteria encounter stresses which can delay or inhibit their growth. To defend against these stresses, bacteria induce both resistance and repair mechanisms. Many bacteria regulate these resistance mechanisms using a group of alternative ? factors called extracytoplasmic function (ECF) ? factors. ECF ? factors represent the largest and most diverse family of ? factors. Here, we demonstrate that the activation of a member of the ECF30 subfamily of ECF ? factors, ?(V) in Bacillus subtilis, is controlled by the proteolytic destruction of the anti-? factor RsiV. We will demonstrate that the degradation of RsiV and, thus, the activation of ?(V) requires multiple proteolytic steps. Upon exposure to the inducer lysozyme, the extracellular domain of RsiV is removed by an unknown protease, which cleaves at site 1. This cleavage is independent of PrsW, the B. subtilis site 1 protease, which cleaves the anti-? factor RsiW. Following cleavage by the unknown protease, the N-terminal portion of RsiV requires further processing, which requires the site 2 intramembrane protease RasP. Our data indicate that the N-terminal portion of RsiV from amino acid 1 to 60, which lacks the extracellular domain, is constitutively degraded unless RasP is absent, indicating that RasP cleavage is constitutive. This suggests that the regulatory step in RsiV degradation and, thus, ?(V) activation are controlled at the level of the site 1 cleavage. Finally, we provide evidence that increased resistance to lysozyme decreases ?(V) activation. Collectively, these data provide evidence that the mechanism for ?(V) activation in B. subtilis is controlled by regulated intramembrane proteolysis (RIP) and requires the site 2 protease RasP.

SUBMITTER: Hastie JL

PROVIDER: S-EPMC3697642 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature

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The activity of σV, an extracytoplasmic function σ factor of Bacillus subtilis, is controlled by regulated proteolysis of the anti-σ factor RsiV.

Hastie Jessica L JL Williams Kyle B KB Ellermeier Craig D CD

Journal of bacteriology 20130517 14

During growth in the environment, bacteria encounter stresses which can delay or inhibit their growth. To defend against these stresses, bacteria induce both resistance and repair mechanisms. Many bacteria regulate these resistance mechanisms using a group of alternative σ factors called extracytoplasmic function (ECF) σ factors. ECF σ factors represent the largest and most diverse family of σ factors. Here, we demonstrate that the activation of a member of the ECF30 subfamily of ECF σ factors, ...[more]

PMID: 23687273

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Project description:Extracytoplasmic function (ECF) ? factors are a diverse family of alternative ? factors that allow bacteria to sense and respond to changes in the environment. ?V is an ECF ? factor found primarily in low-GC Gram-positive bacteria and is required for lysozyme resistance in several opportunistic pathogens. In the absence of lysozyme, ?V is inhibited by the anti-? factor RsiV. In response to lysozyme, RsiV is degraded via the process of regulated intramembrane proteolysis (RIP). RIP is initiated by cleavage of RsiV at site 1, which allows the intramembrane protease RasP to cleave RsiV within the transmembrane domain at site 2 and leads to activation of ?V Previous work suggested that RsiV is cleaved by signal peptidase at site 1. Here we demonstrate in vitro that signal peptidase is sufficient for cleavage of RsiV only in the presence of lysozyme and provide evidence that multiple Bacillus subtilis signal peptidases can cleave RsiV in vitro This cleavage is dependent upon the concentration of lysozyme, consistent with previous work that showed that binding to RsiV was required for ?V activation. We also show that signal peptidase activity is required for site 1 cleavage of RsiV in vivo Thus, we demonstrate that signal peptidase is the site 1 protease for RsiV.IMPORTANCE Extracytoplasmic function (ECF) ? factors are a diverse family of alternative ? factors that respond to extracellular signals. The ECF ? factor ?V is present in many low-GC Gram-positive bacteria and induces resistance to lysozyme, a component of the innate immune system. The anti-? factor RsiV inhibits ?V activity in the absence of lysozyme. Lysozyme binds RsiV, which initiates a proteolytic cascade leading to destruction of RsiV and activation of ?V This proteolytic cascade is initiated by signal peptidase, a component of the general secretory system. We show that signal peptidase is necessary and sufficient for cleavage of RsiV at site 1 in the presence of lysozyme. This report describes a role for signal peptidase in controlling gene expression.

Dataset Information

The activity of ?V, an extracytoplasmic function ? factor of Bacillus subtilis, is controlled by regulated proteolysis of the anti-? factor RsiV.

Publications

The activity of σV, an extracytoplasmic function σ factor of Bacillus subtilis, is controlled by regulated proteolysis of the anti-σ factor RsiV.

Similar Datasets

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