A new study has discovered a specific gene that plays an important role in keeping a balance between food intake and energy use that could have an impact on the weight problems of many Americans.

Scientists from the Florida campus of the The Scripps Research Institute focused on the melanocortin-3 receptor (MC3R) which normally responds to signals of nutrient intake. The development of a new transgenic animal model where expression of the MC3R gene can be selectively "switched on" in different cell types made the findings possible.

"What we discovered was quite a surprise," said Andrew Butler, Scripps Research Associate Professor who led the study. "We thought that the actions of the receptor expressed in the brain would be critical for metabolic homeostasis. However, what we found is that actions of the receptor expressed outside the brain appear to be equally important."

In the study, the researchers found out that the suppression of MC3R expression in the brain and peripheral tissues had a marked impact on metabolic homeostasis (equilibrium).

They noted that mice expressing the MC3R gene in the brain only displayed an obese phenotype (physical appearance) which indicated that actions of this receptor in the brain are not sufficient to protect against weight gain.

According to Butler, the finding that loss of MC3R activity in the periphery impairs metabolic homeostasis is startling. It points to a distinct role for MC3R signaling in the peripheral tissues. How the actions of these receptors impacts on obesity, however, remains to be determined.

"It's clear that these peripheral receptors are important and the new mouse model will let us explore that potential," Butler said.

The study which was published in the November 25, 2011 print edition of The Journal of Biological Chemistry, was supported by National Institutes of Health and the Pennington Biomedical Research Foundation.