Evidence that regulation of intramembrane proteolysis is mediated by substrate gating during sporulation in Bacillus subtilis.

During the morphological process of sporulation in Bacillus subtilis two adjacent daughter cells (called the mother cell and forespore) follow different programs of gene expression that are linked to each other by signal transduction pathways. At a late stage in development, a signaling pathway emanating from the forespore triggers the proteolytic activation of the mother cell transcription factor σK. Cleavage of pro-σK to its mature and active form is catalyzed by the intramembrane cleaving metalloprotease SpoIVFB (B), a Site-2 Protease (S2P) family member.

Addressing Inpatient Beta-Lactam Allergies: A Multihospital Implementation.

Addressing inaccurate penicillin allergies is encouraged as part of antibiotic stewardship in the inpatient setting. However, implementing interventions targeted at the 10% to 15% of inpatients reporting a previous penicillin allergy can pose substantial logistic challenges. We implemented a computerized guideline for patients with reported beta-lactam allergy at 5 hospitals within a single health care system in the Boston area.

Evaluation of a Pharmacist-Directed Vancomycin Dosing and Monitoring Pilot Program at a Tertiary Academic Medical Center.

Background: Consensus guidelines recommend vancomycin doses of 15 to 20 mg/kg every 8 to 12 hours in patients with normal renal function.

Objective: To evaluate the effect of a pharmacist-directed vancomycin dosing and monitoring pilot program on the percentage of patients receiving targeted weight-based dosing recommendations.

Methods: This was a pre-/postevaluation study, approved by the institutional review board at our institution, comparing retrospectively reviewed vancomycin dosing practices hospital-wide between September 1 and September 30, 2010 to patients prospectively managed by a pharmacist-directed vancomycin pilot program between February 1 and April 26, 2011.

Implementation of a dexmedetomidine stewardship program at a tertiary academic medical center.

Background: Brigham and Women's Hospital implemented a dexmedetomidine stewardship program in October 2010 beginning with an institution-specific prescribing guideline. To ensure continued adherence to the prescribing guideline, a pharmacist-driven quality assurance program was implemented in November 2011.

Objective: The primary objective of this study is to describe the role and impact of a dexmedetomidine stewardship program on dexmedetomidine use at a tertiary academic medical center.

Peptidoglycan hydrolysis is required for assembly and activity of the transenvelope secretion complex during sporulation in Bacillus subtilis.

Sporulating Bacillus subtilis cells assemble a transenvelope secretion complex that connects the mother cell and developing spore. The forespore protein SpoIIQ and the mother-cell protein SpoIIIAH interact across the double membrane septum and are thought to assemble into a channel that serves as the basement layer of this specialized secretion system. SpoIIQ is absolutely required to recruit SpoIIIAH to the sporulation septum on the mother-cell side, however the mechanism by which SpoIIQ is localized has been unclear.

FisB mediates membrane fission during sporulation in Bacillus subtilis.

How bacteria catalyze membrane fission during growth and differentiation is an outstanding question in prokaryotic cell biology. Here, we describe a protein (FisB, for fission protein B) that mediates membrane fission during the morphological process of spore formation in Bacillus subtilis. Sporulating cells divide asymmetrically, generating a large mother cell and smaller forespore.

Nucleoid occlusion prevents cell division during replication fork arrest in Bacillus subtilis.

How bacteria respond to chromosome replication stress has been traditionally studied using temperature-sensitive mutants and chemical inhibitors. These methods inevitably arrest all replication and lead to induction of transcriptional responses and inhibition of cell division. Here, we used repressor proteins bound to operator arrays to generate a single stalled replication fork.

A highly coordinated cell wall degradation machine governs spore morphogenesis in Bacillus subtilis.

How proteins catalyze morphogenesis is an outstanding question in developmental biology. In bacteria, morphogenesis is intimately linked to remodeling the cell wall exoskeleton. Here, we investigate the mechanisms by which the mother cell engulfs the prospective spore during sporulation in Bacillus subtilis.

SirA enforces diploidy by inhibiting the replication initiator DnaA during spore formation in Bacillus subtilis.

How cells maintain their ploidy is relevant to cellular development and disease. Here, we investigate the mechanism by which the bacterium Bacillus subtilis enforces diploidy as it differentiates into a dormant spore. We demonstrate that a sporulation-induced protein SirA (originally annotated YneE) blocks new rounds of replication by targeting the highly conserved replication initiation factor DnaA.

Recruitment of SMC by ParB-parS organizes the origin region and promotes efficient chromosome segregation.

Organization and segregation of replicated chromosomes are essential processes during cell division in all organisms. Similar to eukaryotes, bacteria possess centromere-like DNA sequences (parS) that cluster at the origin of replication and the structural maintenance of chromosomes (SMC) complexes for faithful chromosome segregation. In Bacillus subtilis, parS sites are bound by the partitioning protein Spo0J (ParB), and we show here that Spo0J recruits the SMC complex to the origin.

SpoIIIE strips proteins off the DNA during chromosome translocation.

The FtsK/SpoIIIE family of DNA transporters are responsible for translocating missegregated chromosomes after the completion of cell division. An extreme example of this post-cytokinetic DNA segregation occurs during spore formation in the bacterium Bacillus subtilis, where SpoIIIE pumps three-quarters of the chromosome (>3 megabases) into one of the two daughter cells. Here, we investigate the fate of the proteins associated with the translocated DNA.

The ATPase SpoIIIE transports DNA across fused septal membranes during sporulation in Bacillus subtilis.

The FtsK/SpoIIIE family of ATP-dependent DNA transporters mediates proper chromosome segregation in dividing bacteria. In sporulating Bacillus subtilis cells, SpoIIIE translocates much of the circular chromosome from the mother cell into the forespore, but the molecular mechanism remains unclear. Using a new assay to monitor DNA transport, we demonstrate that the two arms of the chromosome are simultaneously pumped into the forespore.

SpoIIQ anchors membrane proteins on both sides of the sporulation septum in Bacillus subtilis.

During the process of spore formation in Bacillus subtilis, many membrane proteins localize to the polar septum where they participate in morphogenesis and signal transduction. The forespore membrane protein SpoIIQ plays a central role in anchoring several mother-cell membrane proteins in the septal membrane. Here, we report that SpoIIQ is also responsible for anchoring a membrane protein on the forespore side of the sporulation septum.

Subcellular localization of a sporulation membrane protein is achieved through a network of interactions along and across the septum.

During the process of spore formation in Bacillus subtilis many membrane proteins localize to the sporulation septum where they play key roles in morphogenesis and cell-cell signalling. However, the mechanism by which these proteins are anchored at this site is not understood. In this report we have defined the localization requirements for the mother-cell membrane protein SpoIVFA, which anchors a signalling complex in the septal membrane on the mother cell side.