Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Cell growth protein forms a “pair” on the cell membrane

Abstract:
Upright instead of horizontal

Cell growth protein forms a "pair" on the cell membrane

Bochum und Dortmund researchers measure the orientation of Ras proteins

Cell growth protein forms a “pair” on the cell membrane

Bochum, Germany | Posted on October 16th, 2012

Bochum biophysicists in collaboration with the MPI Dortmund have for the first time measured the orientation of the Ras protein bound to the cell membrane. The RUB team combined the use of three biophysical methods - infrared spectroscopy, computer simulations and fluorescence measurements - and came to the surprising conclusion that two Ras molecules form a pair to take an upright position on the membrane. It was previously assumed, based on computer simulations, that the protein is located horizontally on the membrane as single molecule. Ras is the central "switch" for cell growth, and malfunction of this protein is an important factor in the development of cancer. "These results put a completely new light on the nano-cluster formation of Ras at the membrane," said Professor Dr. Klaus Gerwert from the RUB Faculty of Biology and Biotechnology. The study was chosen as the cover story for the Biophysical Journal.

Orientation affects protein interactions

The orientation of a protein affects its possible interactions with other proteins. "This is similar to comparing the situations of a guest being welcomed with open arms and the host lying on the couch during the greeting," illustrates Dr. Jörn Güldenhaupt, who conducted the orientation measurements. Few biophysical methods allow the protein orientation to be determined. ATR-FTIR spectroscopy, which has been established by the Chair for Biophysics, is one of them.

Ras molecules are mutually supportive

The false assumption that Ras lies on the membrane was based on earlier computer simulations. Till Rudack from the Bochum research team also took a virtual look at Ras. The result: A single upright Ras molecule very quickly falls over and seems to lie on the membrane. "Something must have supported the Ras in our measurements," said Till Rudack. "And that could only be another Ras molecule that was not present in the simulation." In fact, further computer simulations of two mutually supportive Ras molecules yielded a stable upright orientation - which would fit the experimental results.

Fluorescence resonance energy transfer: a molecular yardstick

The team confirmed the results with another piece of experimental evidence using "FRET" (fluorescence resonance energy transfer). This is currently the best method for detecting interactions between two proteins. Here, researchers mark the Ras proteins with two different dyes. If the proteins interact, they are very close together so that energy is transferred from the one dye to the other. As with a yardstick, the distance between the proteins can be measured from the ratio of the transferred energy. For the Ras-Ras interaction, the biophysicists determined a distance of 4.6 nanometres, or millionths of a millimetre. This corresponded exactly to the distance they had predicted with their computer simulations for a "double-Ras".

Stronger in the group

Earlier studies had shown that Ras molecules are often concentrated in small groups. These so-called nano-clusters consist of four to ten Ras proteins. Up until now, it was assumed that other proteins have to mediate the formation of clusters. "We were able to demonstrate for the first time that Ras itself is actively involved," said Dr. Carsten Kötting, an Assistant Professor. The clustering is a great advantage for Ras. The proteins are able to pass on a signal more clearly in the group, i.e. with fewer errors. The SOS protein, for example, always transmits one signal simultaneously to two Ras molecules. If Ras is present in a double form (as a dimer), this step is much easier. An understanding of the stereo structure of Ras will allow us to adopt novel approaches in drug development. "So far, no drugs have been discovered which act directly on Ras," said Klaus Gerwert. "Ras is to be considered undruggable. The Ras-Ras interface could be a new starting point, however, in the development of Ras drugs."

Project grant

Financial support for the project has come from the Protein Research Department at RUB, from the State NRW as part of the Centre for Vibrational Microscopy (CVM) and from SFB 642 "GTP and ATP-dependent membrane processes" (Professor Gerwert is their spokesperson).

Full bibliographic information

J. Güldenhaupt, T. Rudack, P. Bachler, D. Mann, G. Triola, H. Waldmann, C. Kötting, K. Gerwert (2012): N-Ras forms dimers at POPC membranes, Biophysical Journal, doi: 10.1016/j.bpj.2012.08.043

Editor: Dr. Julia Weiler

####

About Ruhr-Universitaet-Bochum
The sixth largest university in Germany.

For more information, please click here

Contacts:
Prof. Dr. Klaus Gerwert
Chair for Biophysics
Faculty of Biology and Biotechnology
Ruhr-Universität
44780 Bochum, Germany
Tel. +49/234/32-24461

Copyright © AlphaGalileo

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

Conductive Inks: booming to $2.8 billion by 2024 April 17th, 2014

Harris & Harris Group Continues Its Blog Series to Highlight Most Impactful Portfolio Companies With Champions Oncology, Inc. April 17th, 2014

Imaging

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

Govt.-Legislation/Regulation/Funding/Policy

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Nanomedicine

Innovative strategy to facilitate organ repair April 18th, 2014

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

High-temperature plasmonics eyed for solar, computer innovation April 17th, 2014

Discoveries

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Thinnest feasible membrane produced April 17th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

Announcements

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Tools

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

More effective kidney stone treatment, from the macroscopic to the nanoscale April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Aerotech X-Y ball-screw stage for economical high performance Planar positioning April 16th, 2014

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Energy Research Facility Construction Project at Brookhaven Lab Wins U.S. Energy Secretary's Achievement Award April 16th, 2014

IDTechEx Printed Electronics Europe 2014 Award Winners April 1st, 2014

Dais Analytic Wins SBIR Grant: Dais Analytic Receives US Army Small Business Innovation Research Grant to Further Its Demonstrated Successes in Cleaning Most Forms of Wastewater March 28th, 2014

Scientists develop world’s first light-activated antimicrobial surface that also works in the dark March 24th, 2014

Nanobiotechnology

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Biologists Develop Nanosensors to Visualize Movements and Distribution of Plant Stress Hormone April 15th, 2014

In latest generation of tiny biosensors, size isn't everything: UCLA researchers overturn conventional wisdom on nanowire-based diagnostic devices April 11th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

NanoNews-Digest
The latest news from around the world, FREE







  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE