Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ancient enzyme guides healthy eating in mammals

13.04.2005


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.



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.

Heidi Hardman | EurekAlert!
Further information:
http://www.cellmetabolism.org

More articles from Life Sciences:

nachricht Mass spectrometry sheds new light on thallium poisoning cold case
14.12.2018 | University of Maryland

nachricht Protein involved in nematode stress response identified
14.12.2018 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>