Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Macromolecular Shredder for RNA in the Cell Nucleus

03.08.2015

Much in the same way as we use shredders to destroy documents that are no longer useful or that contain potentially damaging information, cells use molecular machines to degrade unwanted or defective macromolecules.

Scientists of the Max Planck Institute of Biochemistry (MPIB) in Martinsried have now shown how the nuclear compartment of the cell uses a specific version of the RNA exosome, a macromolecular machine responsible for the degradation as well as the biogenesis of ribonucleic acids (RNAs). RNAs are ubiquitous and abundant molecules with multiple functions in the cell. One of their functions is, for example, to permit translation of the genomic information into proteins.


Multiple RNA paths in the nuclear exosome complex during pre-ribosomal processing.

Illustration: Debora Makino / Copyright: MPI of Biochemistry

Any errors that occur during the synthesis of RNA molecules or unwanted accumulation of RNAs can be damaging to the cell. The elimination of defective RNAs or of RNAs that are no longer needed are therefore key steps in the metabolism of a cell.

The exosome, a multi-protein complex, is a key machine that shreds RNA into pieces. In addition, the exosome also processes certain RNA molecules into their mature form. In a study two years ago, scientists in the Research Department ‘Structural Cell Biology’ headed by Elena Conti unveiled the X-ray structure of the exosome core complex. The multi-protein complex consists of nine proteins that form a central substrate channel that ends in the protein Rrp44, the exosome RNA degrading center.

Specific shredders for each compartment of the cell

Different cellular compartments, such as the nucleus or the cytoplasm, have their own specific versions of a larger exosome complex bound to specific helper proteins. The MPIB scientists could now reveal how the exosome in the nucleus works together with two protein-subunits called Rrp6 and Rrp47, which are specific only for RNA substrates of the nucleus.

“We could show that the cell has multiple possible paths of degrading nuclear RNA,” explains Debora Makino, one of the authors of the study. One of the pathways leads the RNA substrate into direct degradation by Rrp6 and/or Rrp44, and the other guides the RNA into the processive degradation by Rrp44 via the core RNA exosome channel path. “In this manner, the cell can degrade RNA substrates either completely or trim them precisely when needed,” says Benjamin Schuch, the other author of the study.

Future research will uncover further RNA processing mechanisms involving the core exosome and its various auxiliary proteins, protein complexes, and RNA substrates located throughout all cell compartments.

Original publication:
D.L. Makino*, B. Schuch*, E. Stegmann, M. Baumgärtner, C. Basquin and E. Conti: RNA degradation paths in a 12-subunit nuclear exosome complex. Nature, July 29, 2015
DOI: 10.1038/nature14865

Weitere Informationen:

http://www.biochem.mpg.de/5092413/20150731_conti_exosome - Detailed Press Release
http://www.biochem.mpg.de/conti - Website of the Research Department 'Structural Cell Biology' (Elena Conti)

Anja Konschak | Max-Planck-Institut für Biochemie

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

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 the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>