Montana State University's (MSU) Department of Microbiology and Cell Biology has made significant progress in understanding a unique bacterial immune system, the Phage Anti-Restriction Induced System (PARIS). The research, led by doctoral student Nate Burman and published in Nature, provides new details about how this immune system protects bacteria from viral infections.
A New Understanding of the PARIS System
The PARIS system is distinct in its mechanism of action, recognizing viral proteins rather than nucleic acids—a function that draws an intriguing parallel to human immune responses. While PARIS operates differently from human immunity, this analogy highlights the complexity and diversity of immune systems across different organisms. “CRISPRs aren’t the only bacterial immune systems that exist,” Burman explained. “What’s unique about PARIS is that it recognizes viral proteins instead of nucleic acid. That’s similar to how a human immune response works.”
This study builds on the foundation of CRISPR research, an area where Professor Blake Wiedenheft, Burman's mentor, is internationally recognized. Unlike CRISPR, which has been widely studied and repurposed for gene editing, the PARIS system represents a less understood but potentially equally important aspect of bacterial defense mechanisms.
Visualizing PARIS with Advanced Technology
A key achievement of this study was generating the first complete image of the PARIS system using MSU's cryo-electron microscope, a tool housed in the university’s Cryo-EM Core Facility. This ultra-high-powered microscope allows researchers to peer inside cells and observe the molecular machinery in action. “Using a new state-of-the-art cryo-electron microscope at MSU, Nate was able to ‘see’ the PARIS complex that forms inside of a bacterial cell,” said Wiedenheft. The structure revealed a propeller-shaped complex that consumes ATP as it scans for invading viral proteins, initiating a defense response when a threat is detected.
Implications and Future Research
The discovery that PARIS systems operate in multiple ways opens new avenues for understanding bacterial immunity. Future research will focus on identifying the specific triggers that activate different PARIS systems and exploring how these systems recognize and respond to viral attacks. This knowledge could provide deeper insights into various types of immune responses beyond bacterial systems.
The environment at MSU has been pivotal in fostering these advancements. Burman, who began his research journey as an undergraduate at Carroll College, emphasized the importance of the collaborative atmosphere in Wiedenheft's lab. “Blake’s support is huge, and he really pushes us to think big about small proteins, how they work in nature and how we might use them in new ways,” Burman said.
Publication Details
Burman, N., Belukhina, S., Depardieu, F. et al. A virally-encoded tRNA neutralizes the PARIS antiviral defence system. Nature (2024). https://doi.org/10.1038/s41586-024-07874-3
A New Understanding of the PARIS System
The PARIS system is distinct in its mechanism of action, recognizing viral proteins rather than nucleic acids—a function that draws an intriguing parallel to human immune responses. While PARIS operates differently from human immunity, this analogy highlights the complexity and diversity of immune systems across different organisms. “CRISPRs aren’t the only bacterial immune systems that exist,” Burman explained. “What’s unique about PARIS is that it recognizes viral proteins instead of nucleic acid. That’s similar to how a human immune response works.”
This study builds on the foundation of CRISPR research, an area where Professor Blake Wiedenheft, Burman's mentor, is internationally recognized. Unlike CRISPR, which has been widely studied and repurposed for gene editing, the PARIS system represents a less understood but potentially equally important aspect of bacterial defense mechanisms.
Visualizing PARIS with Advanced Technology
A key achievement of this study was generating the first complete image of the PARIS system using MSU's cryo-electron microscope, a tool housed in the university’s Cryo-EM Core Facility. This ultra-high-powered microscope allows researchers to peer inside cells and observe the molecular machinery in action. “Using a new state-of-the-art cryo-electron microscope at MSU, Nate was able to ‘see’ the PARIS complex that forms inside of a bacterial cell,” said Wiedenheft. The structure revealed a propeller-shaped complex that consumes ATP as it scans for invading viral proteins, initiating a defense response when a threat is detected.
Implications and Future Research
The discovery that PARIS systems operate in multiple ways opens new avenues for understanding bacterial immunity. Future research will focus on identifying the specific triggers that activate different PARIS systems and exploring how these systems recognize and respond to viral attacks. This knowledge could provide deeper insights into various types of immune responses beyond bacterial systems.
The environment at MSU has been pivotal in fostering these advancements. Burman, who began his research journey as an undergraduate at Carroll College, emphasized the importance of the collaborative atmosphere in Wiedenheft's lab. “Blake’s support is huge, and he really pushes us to think big about small proteins, how they work in nature and how we might use them in new ways,” Burman said.
Publication Details
Burman, N., Belukhina, S., Depardieu, F. et al. A virally-encoded tRNA neutralizes the PARIS antiviral defence system. Nature (2024). https://doi.org/10.1038/s41586-024-07874-3