Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly discovered 'platform' for processing dietary fat

05.04.2007
A new "platform" with a crucial role in the body's ability to process and take up fat from the diet has been found, according to a report in the April issue of the journal Cell Metabolism, published by Cell Press.

Researchers discovered a protein that sits on the inner surfaces of capillaries, where it delivers "packages" of dietary fat from the bloodstream to enzymes that prepare them for entry into cells of the body. Once inside cells, the fats are either burned as a rich source of energy or stored for later use.

"We've found a new, very important partner in a process people thought they understood 20 years ago," said Anne Beigneux of the University of California, Los Angeles.

While it is too soon to say whether the finding will have clinical implications—in efforts to limit the body's capacity to store fat, for instance—one thing is for certain: "Soon, every biochemistry book will have to be revised," she said.

Dietary fats in mammals are packaged by the intestine into "chylomicrons," which are large triglyceride-rich lipoproteins, Beigneux explained. After reaching the bloodstream, the triglycerides within chylomicrons are broken down by an enzyme found along the surface of capillaries, mainly in the heart, skeletal muscle, and fat tissue. In those tissues, the so-called lipoprotein lipase enzyme is synthesized, secreted, and transported to the capillaries, where the packaged lipids are taken apart.

The fat "bundles" have to be broken down because the lipids are otherwise unable to get across cell membranes, Beigneux added.

The researchers "stumbled onto" a new player in the process after a team at Genentech found mutant mice with severe chylomicronemia, a condition in which the inability to properly process dietary fat leads to high levels of blood triglycerides.

The mice—which lacked a gene called glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1, or Gpihbp1—exhibited a striking accumulation of chylomicrons in the plasma, even on a low-fat diet, the researchers report. The animals' deficiency caused their blood plasma to become milky as their blood triglyceride levels skyrocketed. Normally, the lipoprotein-binding protein is found at high levels in heart and adipose tissue, the same tissues that express high levels of the enzyme that breaks chylomicrons down, they report.

The researchers conclude that GPIHBP1 is crucial for chylomicron processing. It is located on the inner surface of the capillary and binds both chylomicrons and the processing enzyme, likely forming a platform for lipid breakdown and playing an important role in the delivery of lipid nutrients to cells.

The findings might have direct implications for patients with chylomicronemia, Beigneux said. The disorder in humans has been linked only to defects in the genes encoding the lipid-degrading enzyme or its cofactor, she explained.

"Now, anybody who has chylomicronemia without one of those mutations should be looked at for a mutation in [this platform protein, GPIHBP1]," she said.

Erin Doonan | EurekAlert!
Further information:
http://www.cell.com

Further reports about: Beigneux HDL-cholesterol Triglyceride chylomicron

More articles from Life Sciences:

nachricht For a chimpanzee, one good turn deserves another
27.06.2017 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)

nachricht New method to rapidly map the 'social networks' of proteins
27.06.2017 | Salk Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>