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 More detailed analysis of how cells react to stress
08.02.2016 | Universität Zürich

nachricht A new potential biomarker for cancer imaging
05.02.2016 | Universiti Putra Malaysia (UPM)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: From allergens to anodes: Pollen derived battery electrodes

Pollens, the bane of allergy sufferers, could represent a boon for battery makers: Recent research has suggested their potential use as anodes in lithium-ion batteries.

"Our findings have demonstrated that renewable pollens could produce carbon architectures for anode applications in energy storage devices," said Vilas Pol, an...

Im Focus: Automated driving: Steering without limits

OmniSteer project to increase automobiles’ urban maneuverability begins with a € 3.4 million budget

Automobiles increase the mobility of their users. However, their maneuverability is pushed to the limit by cramped inner city conditions. Those who need to...

Im Focus: Microscopy: Nine at one blow

Advance in biomedical imaging: The University of Würzburg's Biocenter has enhanced fluorescence microscopy to label and visualise up to nine different cell structures simultaneously.

Fluorescence microscopy allows researchers to visualise biomolecules in cells. They label the molecules using fluorescent probes, excite them with light and...

Im Focus: NASA's ICESat-2 equipped with unique 3-D manufactured part

NASA's follow-on to the successful ICESat mission will employ a never-before-flown technique for determining the topography of ice sheets and the thickness of sea ice, but that won't be the only first for this mission.

Slated for launch in 2018, NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) also will carry a 3-D printed part made of polyetherketoneketone (PEKK),...

Im Focus: Sinking islands: Does the rise of sea level endanger the Takuu Atoll in the Pacific?

In the last decades, sea level has been rising continuously – about 3.3 mm per year. For reef islands such as the Maldives or the Marshall Islands a sinister picture is being painted evoking the demise of the island states and their cultures. Are the effects of sea-level rise already noticeable on reef islands? Scientists from the ZMT have now answered this question for the Takuu Atoll, a group of Pacific islands, located northeast of Papua New Guinea.

In the last decades, sea level has been rising continuously – about 3.3 mm per year. For reef islands such as the Maldives or the Marshall Islands a sinister...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

From intelligent knee braces to anti-theft backpacks

26.01.2016 | Event News

DATE 2016 Highlighting Automotive and Secure Systems

26.01.2016 | Event News

 
Latest News

Ocean acidification makes coralline algae less robust

08.02.2016 | Earth Sciences

Online shopping might not be as green as we thought

08.02.2016 | Studies and Analyses

Proteomics and precision medicine

08.02.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>