A newly defined family of proteins has been analyzed by researchers, who say its control over another class of proteins involved in cell division – CAAX proteins – could have major implications for cancer research. Results of their findings were recently published in the journal Nature.

The new protein family is called glutamate intramembrane proteases, and the research team, from The Institute of Cancer Research in London, says the founding member of this family – a protein called Rce1 – plays an important role in converting healthy cells into cancerous ones.

Prof. David Barford, leader of the study from the Medical Research Council but formerly of The Institute of Cancer Research, says:

“Against our expectations, we found the Rce1 protein is so different from any other protein known to science that we need to put it in its own family. Previous studies have found Rce1 interacts with the Ras pathway, which plays a key role in many different types of cancer, so establishing the protein’s unique structure is an important step forward.”

The team notes that CAAX proteins, which are controlled by the newly described Rce1, include this important Ras protein cancer trigger.

Previously, this protein has been difficult to target with traditional drugs, which is why understanding other proteins involved with Ras has been “enormously important” in the struggle to find other targets for drug treatment, say the researchers.

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Rce1 controls proteins that are responsible for turning healthy cells into cancerous ones (pictured), but the discovery of this new protein could help scientists develop focused targets for future cancer drugs.

After studying Methanococcus maripaludis Rce1 in detail, the researchers then used a second bacterium – called Escherichia coli – as a “protein factory” to manufacture M. maripaludis Rce1.

They then purified and crystallized it, after which they used a technique called X-ray diffraction to study the structure of Rce1 in unparalleled detail.

Rce1 is an intramembrane protease – meaning it can cut off certain parts of other membrane-associated proteins – but the researchers were not able to put this protein in any of the three currently known families of intramembrane proteases.

This left the team to determine that they had found a fourth family, with Rce1 as the only known member.

Prof. Barford says their study could one day lead to new potential cancer treatments, but he also adds that their results highlight the uncertainties involved with new research:

Our findings underline just how much of the fundamental processes of life we still do not understand, and could give other cancer researchers their first step on a possible route to new treatments.”

“It is a rare and important moment when scientists discover a new class of proteins,” says Prof. Alan Ashworth, chief executive of The Institute of Cancer Research, “and it is exciting not only for the new insight it gives us, but also for the potential it creates for new anti-cancer strategies.”

The research was funded by Cancer Research UK.

Medical News Today recently reported on a study detailing how older cells circumvent a switch that signals them to stop growing, suggesting that aging cells could be to blame for late-life cancers.