Featured Research

from universities, journals, and other organizations

Ancient Enzyme Guides Healthy Eating In Mammals

Date:
April 29, 2005
Source:
Cell Press
Summary:
An ancient enzyme in the brains of mammals acts as an innate nutritionist of sorts, guiding them to make healthy choices about what to eat, according to new work published in the April issue of Cell Metabolism. The molecular mechanism is likely to be important in all mammals, including humans, that eat a varied diet comprised of meat and vegetables, the researchers said.

An ancient enzyme in the brains of mammals acts as an innate nutritionist of sorts, guiding them to make healthy choices about what to eat, according to new work published in the April issue of Cell Metabolism. The molecular mechanism is likely to be important in all mammals, including humans, that eat a varied diet comprised of meat and vegetables, the researchers said.

Related Articles


David Ron, of the New York University School of Medicine, and his colleagues found in mice that an enzyme known as GCN2 kinase sets off a cascade of events that relays information to the brain about the amino acid content of foods, enabling the animals to adjust their intake in favor of a more balanced meal. The same enzyme in yeast also acts as an amino acid sensor, earlier work has shown.

"This ancient pathway in mice recognizes drops in blood amino acid levels that occur following consumption of food with an imbalanced composition," said Ron. "That recognition culminates in a behavioral response that limits consumption of the imbalanced food and favors, by default, a more balanced diet."

The new findings confirm and extend a recent report by Dorothy Gietzen at the University of California, Davis, detailing the same pathway in rats.

Amino acids are the building blocks of proteins. While many of the 20 amino acids can be synthesized internally, eight "essential" amino acids must be obtained from food. Scientists have long known that omnivorous animals will consume substantially less of a meal lacking a single essential amino acid, in comparison to an otherwise identical meal that is nutritionally complete.

To explore the role of GCN2 kinase in this feeding behavior, the researchers inactivated the enzyme in the brains of mice. GCN2 kinase, known to be an important amino acid sensor, elicits a stress response by modifying a second protein called translation initiation factor 2 (eIF2a).

Mice without the normal complement of GCN2 in the brain failed to exhibit an aversion to imbalanced food, the researchers reported. The protein inactivation also led to a decline in modified eIF2a in a key part of the brain following consumption of an imbalanced meal.

The findings reveal that the ancient amino acid-sensing pathway affects feeding behavior by activating a brain circuit that biases consumption against imbalanced food sources, the researchers said.

While the findings are in mice, "there's no reason to believe that the same mechanism isn't at work in humans," Ron said. However, he suspects that cultural influences coupled with an instinctual drive to consume foods rich in calories might often override the amino acid gauge that would otherwise promote a balanced diet.

###

The researchers include Anne-Catherine Maurin, Céline Jousse, Julien Averous, Laurent Parry, Alain Bruhat, Yoan Cherasse,and Pierre Fafournoux of the Institut National de la Recherche Agronomique de Theix in Saint Genès-Champanelle, France; and Huiqing Zeng, Yuhong Zhang, Heather P. Harding, and David Ron of the Skirball Institute of Biomolecular Medicine at New York University School of Medicine in New York, New York. This work was supported by an NIH grant.

Anne-Catherine Maurin, Céline Jousse, Julien Averous, Laurent Parry, Alain Bruhat, Yoan Cherasse, Huiqing Zeng, Yuhong Zhang, Heather P. Harding, David Ron, and Pierre Fafournoux: "The GCN2 kinase biases feeding behavior to maintain amino acid homeostasis in omnivores"

Publishing in Cell Metabolism, Volume 1, Number 4, April 2005, pages 273-277. www.cellmetabolism.org


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "Ancient Enzyme Guides Healthy Eating In Mammals." ScienceDaily. ScienceDaily, 29 April 2005. <www.sciencedaily.com/releases/2005/04/050428183259.htm>.
Cell Press. (2005, April 29). Ancient Enzyme Guides Healthy Eating In Mammals. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2005/04/050428183259.htm
Cell Press. "Ancient Enzyme Guides Healthy Eating In Mammals." ScienceDaily. www.sciencedaily.com/releases/2005/04/050428183259.htm (accessed October 26, 2014).

Share This



More Health & Medicine News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
Toxin-Packed Stem Cells Used To Kill Cancer

Toxin-Packed Stem Cells Used To Kill Cancer

Newsy (Oct. 25, 2014) — A Harvard University Research Team created genetically engineered stem cells that are able to kill cancer cells, while leaving other cells unharmed. Video provided by Newsy
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins