Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery of new protein could provide new understanding of male fertility

06.08.2007
Scientists have discovered a new enzyme involved in the degradation of proteins inside cells, a process that helps eliminate or recycle proteins that are no longer needed. The unexpected discovery, made by Marcus Groettrup, chair of the immunology department at the University of Constance, Konstanz, Germany, and colleagues, overthrows the idea that protein degradation is initiated by only one enzyme. Also, the new enzyme is very highly expressed in the testis, which could provide a new understanding of male fertility.

“We essentially found that cleanup in the cell is not supervised by one but by two proteins,” Groettrup says. “It is important because everything we know about this cleanup process assumes that only one enzyme initiates it. The second protein we discovered may either share some functions with the first one or do totally different things.”

The new study, to be published in the August 3 issue of the Journal of Biological Chemistry, was selected as a “Paper of the Week” by the journal’s editors, meaning that it belongs to the top one percent of papers reviewed in significance and overall importance.

Before being degraded, proteins are “tagged” with a small protein called ubiquitin. Three types of enzymes are involved in the tagging process. An enzyme called activating enzyme E1 first activates ubiquitin and binds to it. Then the ubiquitin is transferred to a second enzyme called ubiquitin-conjugating enzyme E2. And a third enzyme, called ubiquitin ligase E3 binds to both E2 and the protein to be degraded, so that E2 can transfer the ubiquitin to the protein. By binding to other ubiquitin-carrying E2 enzymes, E3 transfers many ubiquitins to the protein, signaling to the cell that the protein needs to be degraded.

... more about:
»UBE1L2 »Ubiquitin »degradation »enzyme »fertility »testis

Until now, only one type of E1 enzyme for ubiquitin has been known to exist in the human genome, while 34 E2 enzymes and 531 E3 enzymes have been discovered. Because of the large number of E2 or E3 enzymes that have been found, researchers are more likely to find another E2 or E3 enzyme than a new E1 enzyme, which explains why Goetrrup and his colleagues were very surprised to stumble upon one.

“You can picture E1 as the Federal Reserve Bank," Goettrup says. "Until now, scientists have shown that, in all the protein degradation processes that use ubiquitin, E1 is the master bank that distributes money (ubiquitin) to other banks (the E2 enzymes), which then give out credits to their clients (the E3 enzymes). What we found is another Federal Reserve Bank, bringing questions like: "What are the clients of this new master bank"' and 'Are there other master banks that we haven't found yet"' It makes us rethink protein degradation in completely new ways."

The scientists were searching for an enzyme similar to E1 that activates a protein that looks like ubiquitin called FAT10. Surprisingly, the enzyme they found could not activate FAT10 but instead activated ubiquitin itself. The researchers then tested whether this enzyme, which they called UBE1L2, also helped degrade proteins by working with E2 and E3 enzymes. They confirmed that this was indeed the case.

Groettrup and his team also tested whether UBE1L2 was – like the original E1 – expressed in all organs and tissues. They measured the expression levels of UBE1L2 in mice and found that the protein was expressed about five times more in the testis than other organs.

“Again, this was totally unexpected,” Goettrup says. “Unlike the first E1, UBE1L2 might have a specialized role in tissues and in particular in the testis. Going back to the previous analogy of the Federal Reserve Bank, this result shows that UBE1L2’s ‘main client banks’ may be in the testis and that UBE1L2 controls many of the protein degradation processes in that organ.”

Goettrup and colleagues are now planning to investigate which E2 and E3 enzymes work with UBE1L2 and determine whether they also work with the original E1. The scientists also would like to investigate a potential role for UBE1L2 in male fertility and determine why the enzyme is more highly expressed in testes than in ovaries.

ARTICLE: “UBE1L2, a novel E1 enzyme, specific for Ubiquitin,” by Christiane Pelzer, Ingrid Kassner, Konstantin Matentzoglu, Rajesh K. Singh, Hans-Peter Wollscheid, Martin Scheffner, Gunter Schmidtke, and Marcus Groettrup

MEDIA CONTACT: Marcus Groettrup, University of Constance, Konstanz, Germany; tel. +49 7531 88 2130; e-mail: marcus.groettrup@uni-konstanz.de

The American Society for Biochemistry and Molecular Biology is a nonprofit scientific and educational organization with over 11,900 members in the United States and internationally. Most members teach and conduct research at colleges and universities. Others conduct research in various government laboratories, nonprofit research institutions and industry. The Society’s student members attend undergraduate or graduate institutions.

Founded in 1906, the Society is based in Bethesda, Maryland, on the campus of the Federation of American Societies for Experimental Biology. The Society's purpose is to advance the science of biochemistry and molecular biology through publication of the Journal of Biological Chemistry, the Journal of Lipid Research, and Molecular and Cellular Proteomics, organization of scientific meetings, advocacy for funding of basic research and education, support of science education at all levels, and promoting the diversity of individuals entering the scientific work force.

Pat Pages | EurekAlert!
Further information:
http://www.asbmb.org

Further reports about: UBE1L2 Ubiquitin degradation enzyme fertility testis

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>