The enzyme phosphatidic acid phosphatase plays a crucial role in regulating the amount of fat in the human body—and controlling it is of interest in the fight against obesity.
But scientists have now found that getting rid of the enzyme entirely can increase the risk of cancer, inflammation, and other ills. The findings appear in the Journal of Biological Chemistry.
“The goal of our lab is to understand how we can tweak and control this enzyme,” says George M. Carman, professor in the department of food science in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick.
“For years, we have been trying to find out how to fine-tune the enzyme’s activity so it’s not too active, and creating too much fat, but it’s active enough to keep the body healthy.”
The enzyme was discovered in 1957 and Gil-Soo Han, research assistant professor in the Rutgers Center for Lipid Research, discovered the gene encoding the enzyme in 2006. The enzyme determines whether the body’s phosphatidic acid will be used to create fat, or create the lipids in cell membranes.
The study used baker’s yeast as a model organism, since it also contains the key enzyme. Han, lead author of the study, deleted a gene in yeast to eliminate the enzyme. That led to accumulations of phosphatidic acid, with cells making far more membrane lipids than necessary, says Carman.
“We have found that maybe a more critical role for the enzyme is to make sure that cells are not making too much membrane lipid,” Carman says. “If you make too much membrane lipid, you make too much membrane and the cells are permitted to grow uncontrollably, a condition characteristic of cancer.”
Since the discovery of the gene encoding the enzyme, people worldwide have studied the enzyme because of its relation to obesity, lipodystrophy, inflammation, diabetes, and other conditions, Carman says.
Lately, the scientists have been trying to understand the enzyme’s structure and function. The next step is to figure out how to control it, Carman says.
“The key take-home message is that things have to be balanced,” he says. “To keep the balance between making storage fat and membrane lipid, you have to have balanced diet.”