Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Insights to air supply

12.04.2010
Teruhisa Hirai of the RIKEN SPring-8 Center, Harima, and colleagues have obtained structural information about the physiologically important protein called erythrocyte anion exchanger 1 (AE1)1.

As well as being expressed in the kidney, AE1 is the most abundant protein in the membrane of red blood cells, or erythrocytes, and helps prevent tissue damage by regulating oxygen supply.

Carbon dioxide, produced when food is burnt for energy, is released into the bloodstream and, on encountering erythrocytes, is converted into bicarbonate (HCO3¯) by the enzyme carbonic anhydrase bound to AE1. In a crucial step—the ‘chloride shift’—chloride is exchanged for HCO3¯ across the erythrocyte membrane via AE1. This lowers erythrocyte pH, resulting in the regulated release of oxygen from hemoglobin.

Despite its importance, there is limited structural information about AE1, particularly the membrane-spanning domain. “Like many membrane proteins, AE1 is very fragile, making structural information difficult to obtain,” says Hirai.

Naotaka Hamasaki and colleagues at Nagasaki International University and Kyushu University purified AE1 stably with the membrane domain fixed in an outward-open conformation, and good two-dimensional crystals were prepared at RIKEN by Tomohiro Yamaguchi. “These were critical steps for structural analysis,” explains Hirai.

The researchers merged 31 images, each taken from a different angle, to produce a three-dimensional image. Interestingly, they found structural similarities between AE1 and a bacterial transporter protein related to a class of chloride channels called ‘ClC channels’ found in animals, including humans.

DNA sequence information is available for the anion exchanger and ClC gene families, but the researchers are the first to uncover structural similarities between the encoded proteins.

ClC channels of mammals conduct chloride ions and are involved in regulating the electrical excitation of skeletal muscles. The bacterial protein, however, functions as a transporter, exchanging chloride ions and protons across the bacterial membrane.

“AE1 has a putative chloride binding site similar to that of the bacterial ClC protein, although this is yet to be proven biochemically,” explains Hirai.

The observed resemblance between AE1 and ClC should help address the chloride transport mechanism, which is not well understood for either family.

“We need to improve the resolution of the current outward-open conformation structure of AE1 and solve the structure of the inward-open conformation to understand the conformational change during transport,” Hirai notes.

AE1 mutations are associated with the human genetic disorders Southeast Asian ovalocytosis and distal renal tubular acidosis, so structural knowledge of AE1 might eventually lead to treatments.

The corresponding author for this highlight is based at the Three-dimensional Microscopy Research Team, RIKEN SPring-8 Center

Journal information

1. Yamaguchi, T., Ikeda, Y., Abe, Y., Kuma, H., Kang, D., Hamasaki, N. & Hirai, T. Structure of the membrane domain of human erythrocyte anion exchanger 1 revealed by electron crystallography. Journal of Molecular Biology 397, 179–189 (2010).

| Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6222
http://www.researchsea.com

More articles from Life Sciences:

nachricht Bare bones: Making bones transparent
27.04.2017 | California Institute of Technology

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>