The Stagljar Lab develops a faster method to detect protein interactions
CLIP LUX enables rapid and sensitive measurement of protein interactions in living cells
Protein–protein interactions are central to nearly every cellular process and are a major focus in drug development. However, existing methods for detecting these interactions in mammalian cells require trade offs. Some approaches provide strong signal amplification but depend on transcription, which slows detection and introduces background noise. Others deliver fast results but lack the sensitivity needed to detect weaker or less abundant interactions.
Researchers in the lab of Dr. Igor Stagljar have developed CLIP LUX, described in a recent paper published in Disease and Therapeutics, to address this gap. The system combines the speed of luminescent detection with the signal amplification typically associated with transcription based assays, allowing interactions to be measured in real time with reduced background.
CLIP LUX operates through a genetically encoded mechanism in which protein interaction triggers a cascade of molecular events. Split ubiquitin components reassemble, leading to cleavage of a reporter construct. The resulting product is captured through N-degron recognition, which brings together luciferase fragments and produces a measurable luminescent signal. Because this process does not rely on transcription, it enables faster and more direct readouts of protein interactions in living cells.
This design allows CLIP LUX to detect interactions across a range of biological contexts. The system demonstrates sensitivity to both membrane and cytosolic interactions and can distinguish changes driven by specific mutations, including variants in EGFR and KRAS. It also supports analysis of ligand dependent signaling and responses to small molecule inhibitors.
The platform is particularly suited for applications in drug discovery. It enables measurement of interaction changes in response to targeted compounds, including inhibitors, molecular glues, and PROTACs. By supporting rapid and quantitative detection, it provides a framework for high throughput screening and for studying how interactions evolve over time.
CLIP LUX has been validated in mammalian cells and shows strong signal output with low background. Its ability to capture both rapid kinetics and cumulative signal provides an advantage for detecting interactions that are transient or present at low abundance.
This work provides a method for studying protein interactions with improved speed and sensitivity, supporting both basic research and the development of therapeutic strategies.
This work was supported by the Barrett Foundation, the Robert Corcoran Drug Discovery Funds, the Canadian Institutes of Health Research (CIHR), the Ontario Research Fund: Research Excellence (ORF-RE), and PRiME, next-generation precision medicine initiative at the University of Toronto.
