New Technique Reveals Ubiquitin's Surprising Role in Sugar Regulation
For the first time, the protein ubiquitin—best known for tagging other proteins for destruction—has been found attaching to a non-protein molecule: the stored sugar glycogen.
Researchers at the Walter and Eliza Hall Institute (WEHI) in Melbourne have developed a new technique to study the molecule ubiquitin, revealing that it can attach to glycogen—a stored form of sugar—in liver and muscle cells. The findings were published in Nature.
Key Findings- The research team, led by Professor David Komander and Dr. Simon Cobbold, developed a method called NoPro-clipping.
- This technique enabled the first conclusive detection of ubiquitin’s interaction with a non-protein molecule.
- Ubiquitin was found attached to glycogen in both mouse models and human muscle tissue.
- In fasting mice, the number of ubiquitin tags on glycogen increased, suggesting a role in sugar regulation.
Ubiquitin is a small protein present in all complex organisms. It has historically been understood as a signal that tags other proteins for degradation. This study is the first to provide evidence that ubiquitin may also act on non-protein molecules, such as sugars.
Researcher Statements"This finding is significant. Ubiquitin’s role in protein tagging has been established for decades, but the discovery of its interaction with sugars was unexpected."
— Professor David Komander, WEHI
"The experimental results were consistently positive, which I would characterize as rare in a scientific career."
— Dr. Simon Cobbold, WEHI
Professor Sharad Kumar (University of Adelaide), who was not involved in the study, called the finding significant but stated that further physiological and genetic studies are required to fully understand its implications.
Potential Implications and Next Steps- Directly controlling glycogen levels could offer a new approach to addressing metabolic conditions such as obesity, diabetes, and heart disease.
- The discovery may also be relevant to rare genetic disorders involving glycogen storage.
- The research team noted that additional studies are needed before the finding can be translated into clinical treatments.
- The NoPro-clipping technique may enable other scientists to investigate ubiquitin’s interactions with other molecules, such as those found in viruses or bacteria.