A functional screen for bacterial ubiquitin regulation identifies an unusual Pseudomonas aeruginosa E3 ligase.

A novel Pseudomonas aeruginosa E3 ligase, PUL-1, was identified as a key regulator of virulence, revealing a unique mechanism of bacterial ubiquitin manipulation.

• Why it matters: Understanding bacterial strategies to hijack host ubiquitination is crucial for developing new antimicrobial therapies, especially since many effectors lack homology to known eukaryotic regulators.
• What they did: A functional screening workflow was developed and applied to secreted bacterial effectors, leading to the discovery of PUL-1, a cryptic E3 ligase with no prior known homologs.
• The result: PUL-1's ligase activity significantly influences P. aeruginosa virulence in animal models, highlighting its potential as a target for intervention and expanding knowledge of bacterial ubiquitin regulation.