WEHI researchers have led a major global effort to create the first authoritative atlas for a class of enzymes that regulate almost every cellular process in the human body.
Dr Ngee Kiat (Jake) Chua and Dr Rebecca Feltham spearheaded the global study that has resolved more than 18 years of inconsistencies in their research field. Image Credit: Walter and Eliza Hall Institute of Medical Research (WEHI)
Published in Cell, the breakthrough study establishes the first gold-standard reference for all human E3 ligases, resolving more than 15 years of inconsistencies within the field.
The atlas will enable researchers to study E3 ligases in unprecedented detail, paving the way for the development of enhanced therapies for diseases linked to these enzymes, including cancer, immune disorders and neurological conditions.
At a Glance
- WEHI leads unprecedented global study to establish the first unified and expert-curated atlas for one of life’s most important enzyme families: E3 ligases.
- The new compendium, made publicly available online, standardises more than 15 years of fragmented and often conflicting annotations into a single gold-standard reference.
- The findings provide a powerful foundation for developing new and precise medicines for diseases including cancer, immune disorders and neurological conditions.
A Long-Standing Gap in Biological Discoveries
E3 ligases are enzymes that control the fate and function of proteins in virtually every cellular process.
These enzymes act as cellular ‘gatekeepers’, deciding which proteins should be activated, silenced and destroyed.
They do this by attaching a small molecule called ubiquitin onto proteins to ‘tag’ them, helping the cell control what proteins do and whether they are repaired, relocated, or destroyed.
Errors in these control systems can sometimes lead to an accumulation of old or damaged proteins, which can trigger a broad range of diseases.
Despite decades of being linked to human health, there are disparities about how the scientific community defines E3 ligases – making it challenging to build a coherent understanding of how these enzymes function in health and disease.
The new atlas, known as the human E3‑ome, is a landmark unified classification framework that changes this.
Corresponding author and WEHI Laboratory Head Dr Rebecca Feltham said the atlas marks the first time experts in the field have collectively agreed on what the human E3 ligase family looks like since their discovery in the 1980s.
“This is a major advance in a field where information has been spread across many different studies making it difficult to see the full picture,” Dr Feltham, said.
“The lack of a unified E3 ligase compendium has been one of the most persistent blind spots in human biology.”
“We now have a gold-standard reference for the field that will enable discoveries for a wide spectrum of diseases that simply weren’t possible before.”
In the four-year study, WEHI researchers along with worldwide specialists collated more than 1100 historically proposed E3 genes, reviewing domain structural features, protein domains and interaction data to evaluate the evidence supporting each candidate.
Of these, 672 met the highest‑confidence criteria.
Previous estimates about the number of existing E3 ligases widely varied – with published research ranging from approximately 300 to over 1000.
When researchers analyze E3 ligases now, their findings will be more accurate and comparable because of the E3-ome, This will open the field wide open in terms of what research questions can be explored and transform our understanding of this field for years to come.”
Dr Rebecca Feltham, Author and Laboratory Head, WEHI
The study builds on foundational research conducted in 2008 by researchers at The Scripps Research Institute, who became the first to develop the human E3 ligase annotation.
Powering Future Discoveries
Technologies like PROTACs, molecular glues and emerging E3 inhibitors rely on hijacking or modulating E3 ligase activity to eliminate harmful proteins.
First author and WEHI postdoctoral researcher, Dr Ngee Kiat (Jake) Chua, says the E3‑ome provides a critical framework for new drug targets and therapeutic strategies, while also highlighting previously overlooked E3 ligases that may hold untapped therapeutic potential.
“E3 ligases are at the center of a rapidly expanding therapeutic frontier, becoming central to how we design medicines,” Dr Chua said.
“Our study systematically analyzed genetic and disease association data across the E3 ligase family, providing a clearer view of E3 ligases across select disease contexts.
“We also mapped where E3 ligases reside inside cells and across the human body, making it easier for researchers to understand how these regulatory systems fail in disease and how they can be corrected.
“The unprecedented insight provided by the E3-ome will support the development of more precise medicines to target disease mechanisms directly.”
A Global Collaboration Pioneers the Compendium
The study represents one of the largest of its kind in the ubiquitin field between multiple institutions across Australia, New Zealand, Canada, Germany, Switzerland, the UK and USA.
More than 40 scientists in ubiquitin biology, structural biology, genetics, computational analysis and E3 ligases banded together for the study.
The human E3-ome was made possible by recent advances in scientific technologies, including artificial intelligence-driven analysis and large-scale human population genetics datasets, which allowed researchers to evaluate E3 ligases with unprecedented depth and accuracy.
While the E3-ome is a pioneering resource, researchers emphasise the 672 enzymes currently defined is not a static number.
This figure is expected to grow as new structural, biochemical and genetic data become available.
To support ongoing discovery, researchers have made the complete E3 ligase compendium publicly available, enabling other researchers to build on the classification and functional insights.
The continuously updated version of the E3‑ome is available online at: (https://github.com/FelthamLaboratory/E3-ome).
This research is supported by the Galbraith Family Charitable Trust, the National Health and Medical Research Council, Wellcome, The Marian and E.H. Flack Fellowship, and the Australian Government.