Lab Canada

Protein discovery key to immune response and cancer

Saskatoon, SK – January 13, 2004 – University of Saskatchewan health scientist Dr Wei Xiao and his research team have discovered a pair of proteins that are significant in stress responses within cells. They say this finding that could lead to new approaches to drug design for treating cancer and viral infections such as SARS and HIV.

The discovery of the protein MMS2 and the way it works with another protein, UBC13, in the complex web of communications within cells to create an immune response was reported in the January 8 issue of Nature.

The research was part of a larger investigation involving California scientists studying immune response. The U of S research was funded by the Canadian Institutes of Health Research.

Dr Xiao, professor and head of the microbiology and immunology department, says the wider investigation focused on finding a tiny protein, an essential link in the chain of events resulting in cells’ efforts to defend the vast ocean of the human body against invaders such as viral and bacterial infections. The protein dubbed NEMO by the researchers performs like a switch activating the immune response.

The U of S contribution was discovering that MMS2 and UBC13 operate together to motivate NEMO. The overall research clarifying this interaction provides a missing link in the chain of events that starts with an intrusion such as exposure to a virus and ends with an immune response.

When the protein duo activates NEMO and triggers the immune response to fight invaders, cells multiply rapidly. This is useful in combating an infection, Dr Xiao says. “But if the chain reaction gets activated all the time, without the presence of an invader, the result is uncontrolled cell division and tumours,” he adds.

Thus, clarifying the role of the protein duo and NEMO has implications for drug development as well as identifying and treating viral diseases and some forms of cancer.

Some antibodies capable of acting on the protein duo have been developed at the U of S and recently licensed for research, says Dr Xiao. Down the road, this research could revolutionize the diagnosis and treatment of immune diseases and cancer, by enabling scientists to boost the immune response to fight infections or, conversely, to halt uncontrolled cell division that would result in cancer.

Dr Xiao says the protein duo of UBC13 and MMS2 was actually identified a few years ago but the protein structure was only recently determined in a collaboration with University of Alberta researchers that involved using a synchrotron in Brookhaven, New York.

“We will be collaborating further with other researchers on the U of S campus, using the Canadian Light Source (CLS) synchrotron,” says Dr Xiao. These studies will focus on the structures of other proteins interacting with the protein duo. The U-of-S-owned CLS ( is to start operations later this year.