NEW STUDY. The protein PAQR-2 is specifically necessary to handle food that contains saturated fats. This discovery, which has now been published in the journal PLoS Genetics, is the result of long-term cooperation between research teams at the Faculty of Science and Sahlgrenska Academy.
Fat is important to the human body, not just as a way to store energy, but also as an important building block. And every membrane that surrounds the cell and its inner organelles consists mainly of fat.However, not all fats are the same. Saturated fats, which are abundant in animal fats, tend to form “rigid” cell membranes. Conversely, unsaturated fats, such as those found in vegetable oils, tend to form “fluid” membranes. For the cells to function properly, membranes must have just the right degree of fluidity to allow proteins to move within the membranes, interact with each other and generally function properly.
“In order for the cells to be able to function properly, the membrane must have just the right degree of fluidity to allow proteins to move inside the membranes, interact with each other and function correctly,” says Marc Pilon, Professor of Genetics at University of Gothenburg, who led to the research study now being published in the scientific journal PLoS Genetics.
The strength of cooperation
These research findings are an example of how researchers in different research domains succeed in achieving more progress together than they would have individually. Co-authors of the article are also Jan Borén and Marcus Ståhlman, whose team is focusing on lipid metabolism and how disruptions in the metabolism of fats give rise to diseases. Thanks to a grant from the Lundberg Foundation, the team has been able to establish a method platform for advance analyses of lipids called lipidomics. Marcus Ståhlman, who is responsible for the lipidomics platform, analyzed lipid composition in mutated C.elegans that were fed fats with different compositions.
“Marc is a fantastically innovative and skilled researcher who works with C.elegans, which is an incredibly interesting and powerful model system,” says Jan Borén, and continues.
“Many people might be surprised that studies in C.elegans roundworms may be relevant to human pathophysiology, but these studies show how we’re able to maintain functioning cell membranes despite the intake of saturated fat. The fats are vital building blocks for the body, but it’s known that a high intake of saturated fat increases the risk of insulin resistance. We’re trying to understand the underlying mechanisms of this.”
Small worm protected from saturated fat by one protein
The fats in the cell membrane are mainly obtained in food. A small worm, C. elegans, a popular model organism used in research worldwide, has a special protein that is specifically necessary for handling food that contains saturated fat. The worm contains a protein, PAQR-2, which thrives on a diet that contains saturated fats.
“We discovered that if we fed saturated fats to mutated worms that lacked PAQR-2, the cell membrane became stiff and the worms ultimately died. So the protein PAQR-2 is important for surviving when food contains saturated fats,” says Marc Pilon.
The next step in the research was to investigate if humans also have a protein that does the same job as the worm’s protein PAQR-2.
Similar protein in humans
When DNA sequences were compared, the researchers found that the worm’s protein (PAQR-2) is very similar to two human proteins called AdipoR1 and AdipoR2. They are described in scientific literature as proteins that protect against diabetes, but what the exact cellular functions are has not been fully established.
“We found that the human AdipoR2 was similar to the worm’s PAQR-2. Both are evolutionarily preserved proteins that are significant to preventing toxic effects on the cell membrane by saturated fats,” says Marc Pilon.
The article is published in the scientific journal PLoS Genetics.
TEXT: CARINA ELIASSON/ELIN LINDSTRÖM CLAESSEN