Molecular Glues & Protein Degradation: Cell Screening Breakthrough

Researchers at the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences have developed a large-scale cell screening method to identify molecular glues, compounds that trigger the degradation of specific proteins within cells. The discovery, published initially in February 2026, offers a new avenue for drug development targeting previously intractable proteins.

The approach focuses on identifying modest molecules capable of inducing protein degradation through various cellular mechanisms, moving beyond traditional methods that rely on inhibiting protein function. This new strategy is particularly relevant for therapeutic targets that have proven difficult to address with conventional small-molecule inhibitors, according to a recent perspective published in Nature.

Two primary categories of degraders are currently being investigated: PROTAC-type degraders, which recruit intracellular ubiquitin ligases to target proteins, and monovalent degraders, including molecular glues. Molecular glues function by creating new interactions between proteins, leading to their ubiquitination and subsequent degradation by the cell’s natural protein disposal system. The research highlights the importance of high-throughput screening (HTS) methodologies in identifying these novel degraders.

Key metrics used to assess the effectiveness of these degraders include DC50 – the concentration required for half-maximal degradation – and Dmax, which represents the maximum degradation achievable. Researchers note that degraders can be “partial,” meaning the amount of target protein degraded may plateau before complete depletion.

The screening process utilizes cell-based assays, including those employing luciferase and HaloTag reporters, to measure small-molecule-induced degradation pathways in living cells. An engineered cereblon, a component of the cellular ubiquitin ligase complex, has also been developed to optimize the screening process for molecular glues, according to research published in Cell Chemical Biology.

Scientists emphasize the challenges inherent in screening for molecular glues, but also the significant opportunities they present for drug discovery. Current and future methods for both cell-based and cell-free screening are being explored to fully exploit the potential of these compounds. A proteome-wide atlas of drug mechanism of action is also being developed to further understand how these degraders function.

The research builds on recent discoveries demonstrating that even small, monovalent molecules can leverage cellular mechanisms to induce protein degradation. Further investigation is ongoing to identify degrader compounds from diverse chemical collections and to refine screening strategies and assay technologies.