Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Heidelberg Researchers Decode Key Component of Cellular Protein Transport System

04.04.2014

Central element of signal recognition particle characterised through structural biology

In their research on cellular protein transport, Heidelberg researchers have succeeded in characterising the structure and function of another important element of this complex transport system. At centre stage is the signal recognition particle, or SRP, the molecular “postman” for the sorting and membrane insertion of proteins. The team led by Prof. Dr. Irmgard Sinning of the Heidelberg University Biochemistry Center was now able to decode an important and so far not characterised SRP component. The results of this research were published today in “Science”.

Every cell contains hundreds of proteins, more than a third of which must be sorted out for incorporation into cell membranes or export from the cell. SRP is the molecular “postman” responsible for this process. Cellular traffic falls apart without SRP logistics. With the aid of a built-in transport signal, SRP packages are retrieved right at the ribosomes, the synthesis factories of the cell. From there they go to the outbox, the translocation channel. In the human organism, SRP is a macromolecular complex consisting of a ribonucleic acid, the SRP RNA, and six proteins bound to it. While four of these proteins are understood at the atomic-detail level, the two largest ones – SRP68 and SRP72 – had “stubbornly resisted closer study,” explains Prof. Sinning.

The Structural Biology department headed by Irmgard Sinning has now succeeded in characterising an essential component of the SRP system, the RNA binding domain of SRP68. The Heidelberg researchers were focussed on how this protein binds to SRP RNA. They discovered that SRP68 has an arginine-rich motif (ARM), which is not only responsible for binding, but also significantly alters the structure of the SRP RNA. The “strong ARM” bends the RNA into its functional form. “Without this modification, the SRP would not be able to bind to the ribosomes correctly, which would block transport of newly synthesized proteins to the translocation channel,” adds Prof. Sinning.

The analysis of earlier electron microscopy and biochemical data allows for even further conclusions. Bending the RNA pushes two bases outward, which make direct contact with the ribosome. Once the translocation channel is reached, the contact breaks off, and these bases are available for regulating the motor system of translocation. “Our research on the ‘strong ARM’ of protein translocation allowed us to fill in one of the last remaining gaps of the SRP system,” underscores Dr. Klemens Wild from Prof. Sinning’s department.

Internet information:
http://www.bzh.uni-heidelberg.de/sinning

Original publication:
J.T. Grotwinkel, K. Wild, B. Segnitz and I. Sinning: SRP RNA Remodeling by SRP68 Explains Its Role in Protein Translocation, Science (4 April 2014), Vol. 344 no. 6179 pp. 101-104, doi: 10.1126/science.1249094

Contact:
Prof. Dr. Irmgard Sinning
Heidelberg University Biochemistry Center
Phone: +49 6221 54-4781
irmi.sinning@bzh.uni-heidelberg.de

Communications and Marketing
Press Office, phone: +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw

Further reports about: Biochemistry Cellular Component Protein RNA SRP Sinning binding breaks proteins responsible ribosomes structure translocation

More articles from Life Sciences:

nachricht 100-million-year-old scale insect practiced brood care
31.03.2015 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Moss as a pioneer of water conservation
31.03.2015 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

NASA's Hubble and Chandra Discover Dark Matter Is Not as Sticky as Once Thought

31.03.2015 | Physics and Astronomy

UAB Rolls Out New Technology to Help Users Combat Mobile Malware Attacks

31.03.2015 | Information Technology

The Dawn of DUNE

31.03.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>