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 New Computer Model Could Explain how Simple Molecules Took First Step Toward Life
29.07.2015 | Brookhaven National Laboratory

nachricht Switch for building barrier in roots
29.07.2015 | The University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

Im Focus: NASA satellite camera provides 'EPIC' view of Earth

A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.

The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

A New Litmus Test for Chaos?

29.07.2015 | Physics and Astronomy

New Computer Model Could Explain how Simple Molecules Took First Step Toward Life

29.07.2015 | Life Sciences

New ERC calls published under Horizon 2020

29.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>