Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How “Quality Control” Functions in Ribosome Assembly

19.11.2013
Heidelberg scientists identify the role of a specific protein in the control process

Like automobiles, ribosomes must pass through “quality control” after their many components are assembled. Only then can they be taken to their destination and proceed with their task – making proteins in the cell.


Quality control and ribosome export from cell nucleus to cytoplasm (schematic diagram)
Image: Ed Hurt

A team of scientists led by Prof. Dr. Ed Hurt at Heidelberg University Biochemistry Center investigated an important component in this control process. The researchers demonstrated that a specific protein, which occurs in all cells from yeast to humans, works like a molecular control switch and prevents incomplete ribosomes from leaving the “assembly hall”. The team’s findings have been published in “Nature“.

Ribosomes are macromolecular complexes consisting of a large number of parts comprising ribonucleic acids and ribosomal proteins arranged in a specific three-dimensional structure. Correct ribosome assembly is essential for the survival of all cells. The assembly process for these many components is subject to strict rules, similar to an automobile assembly line.

Before the finished car leaves the assembly hall, it is tested for full functionality and then sent to its destination. According to Prof. Hurt, there has been little research thus far on how this “quality check” takes place in ribosome assembly. The Heidelberg scientists have now identified the function of a protein from the energy-consuming GTPase family in this process.

Only correctly assembled ribosomes make it from the “assembly hall” in the cell nucleus to the cytoplasm, where they set about their real task of synthesising proteins. For export to the cytoplasm, nascent ribosomes must pass through a quality checkpoint for binding to export factor Nmd3.

Before binding, however, a signal has to be given that the assembly of the ribosome is correct and complete. Until then, a type of “control officer” occupies the site earmarked for Nmd3. The Heidelberg team has now demonstrated that this function is performed by a member of the GTPase protein family known as Nug2. Only when a specific enzyme swings into action to remodel the assembled ribosome for export to the cytoplasm, thereby consuming the energy stored by the GTPase, does the Nug2 “control officer” vacate its place and make way for export factor Nmd3. This is how the export of incomplete ribosomes is prevented.

Now that Prof. Hurt’s team has been successful in identifying the role played by control agent Nug2 in ribosome assembly, the researchers hope to gain even further insight into the functions of related proteins. These so-called nucleostemins are found in higher eukaryotes, including those of humans. The Heidelberg scientists plan to decipher the molecular mechanisms that various enzymes from the nucleostemin family use to combine the two fundamental cellular processes of ribosome formation and cell proliferation. Scientists at the University of Edinburgh (UK) also cooperated in the current research.

Online information:
Research group of Prof. Dr. Ed Hurt:
http://www.uni-heidelberg.de/zentral/bzh/hurt
Heidelberg University Biochemistry Center:
http://www.bzh.uni-heidelberg.de
Original publication:
Y. Matsuo, S. Granneman, M. Thoms, R.-G. Manikas, D. Tollervey and E. Hurt: Coupled GTPase and remodeling ATPase activities form a checkpoint for ribosome export, Nature (17 November 2013), doi:10.1038/nature12731
Contact;
Prof. Dr. Ed Hurt
Heidelberg University Biochemistry Center
Phone: +49 6221 54-4173
ed.hurt@bzh.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>