Not unlike an urban restaurant, the success of a bacterial cell depends on three things: localization, localization and localization. But the complete set of controls by which bacteria control the movement of proteins and other essential biological materials globally within the confines of their membrane walls has been something of a mystery. Now, researchers at the University of Washington have parsed out the localization mechanisms that E. coli use to sort through and organize their subcellular components.
This is a cluster of colorized E. coli as seen under a scanning electron microscope. Image courtesy of Janice Haney Carr/CDC.
Not unlike an urban restaurant, the success of a bacterial cell depends on three things: localization, localization and localization. But the complete set of controls by which bacteria control the movement of proteins and other essential biological materials globally within the confines of their membrane walls has been something of a mystery. Now, researchers at the University of Washington have parsed out the localization mechanisms that E. coli use to sort through and organize their subcellular components.
"Despite their small size and relative simplicity, bacterial cells appear to possess a robust and complex level of subcellular organization, both spatially and temporally, that was once thought to only exist in more complex organisms," says Nathan Kuwada, a postdoctoral fellow in the lab of Paul Wiggins at the University of Washington. "We wanted to know how many mechanisms bacteria possess to localize subcellular components, and to answer this question, we set out to image the localization pattern of nearly every protein in a bacterial cell for the entire cell cycle."
Kuwada will describe the group's findings this week at the Biophysical Society's 59th annual meeting in Baltimore, Md.
E. coli localize nearly one-fifth of their proteins to specific subcellular sites, but until now, the cell-cycle localization behavior of only a small subset of proteins had been characterized in detail.
Kuwada and his colleagues sought to remedy this by imaging an existing library of green-fluorescent protein fusions in E. coli by use of a high-throughput live-cell imaging scheme. This allowed them to image close to a thousand individual protein fusions in growing cells for 6-8 hours, providing them with hundreds of complete cell cycles for each protein.
Using custom image processing software, the researchers processed and organized the thousands of images from each experiment, allowing them to quantitatively compare the localization patterns on a genomic scale. The researchers also developed a public online database with all of their raw and processed data in a browsable and searchable form at: http://mtshasta.phys.washington.edu/localizome
Rather than a small number of patterns combining in various permutations determined by function, the researchers found that bacteria possess a large number of distinct patterns with subtle spatial and temporal differences.
For example, Kuwada and his colleagues also observed that the DNA-binding proteins were asymmetrically distributed towards the daughter cell during cell divisions, despite the morphological symmetry between parent and daughter cells.
"Although the asymmetry is somewhat weak, it is still statistically significant and we think it must have an exciting biological significance," Kuwada says. "This finding, which is only observable using our complete-cell-cycle approach, potentially has many biological consequences that we are currently trying to better understand."
Future work for Kuwada and his colleagues includes further exploring the specific mechanisms that drive subcellular organization, through targeting the behavior of specific groups of proteins such as transcription factors with increased precision.
Source: Biophysical Society
Stay prepared and protected with Infection Control Today's newsletter, delivering essential updates, best practices, and expert insights for infection preventionists.
Reducing Hidden Risks: Why Sharps Injuries Still Go Unreported
July 18th 2025Despite being a well-known occupational hazard, sharps injuries continue to occur in health care facilities and are often underreported, underestimated, and inadequately addressed. A recent interview with sharps safety advocate Amanda Heitman, BSN, RN, CNOR, a perioperative educational consultant, reveals why change is overdue and what new tools and guidance can help.
New Study Explores Oral Vancomycin to Prevent C difficile Recurrence, But Questions Remain
July 17th 2025A new clinical trial explores the use of low-dose oral vancomycin to prevent Clostridioides difficile recurrence in high-risk patients taking antibiotics. While the data suggest a possible benefit, the findings stop short of statistical significance and raise red flags about vancomycin-resistant Enterococcus (VRE), underscoring the delicate balance between prevention and antimicrobial stewardship.
What Lies Beneath: Why Borescopes Are Essential for Verifying Surgical Instrument Cleanliness
July 16th 2025Despite their smooth, polished exteriors, surgical instruments often harbor dangerous contaminants deep inside their lumens. At the HSPA25 and APIC25 conferences, Cori L. Ofstead, MSPH, and her colleagues revealed why borescopes are an indispensable tool for sterile processing teams, offering the only reliable way to verify internal cleanliness and improve sterile processing effectiveness to prevent patient harm.
The Next Frontier in Infection Control: AI-Driven Operating Rooms
Published: July 15th 2025 | Updated: July 15th 2025Discover how AI-powered sensors, smart surveillance, and advanced analytics are revolutionizing infection prevention in the OR. Herman DeBoard, PhD, discusses how these technologies safeguard sterile fields, reduce SSIs, and help hospitals balance operational efficiency with patient safety.
Targeting Uncertainty: Why Pregnancy May Be the Best Time to Build Vaccine Confidence
July 15th 2025New national survey data reveal high uncertainty among pregnant individuals—especially first-time parents—about vaccinating their future children, underscoring the value of proactive engagement to strengthen infection prevention.