Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Imaging

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Cambridge Nanotherm partners with Inabata for global sales and distribution June 20th, 2017

GLOBALFOUNDRIES Launches 7nm ASIC Platform for Data Center, Machine Learning, and 5G Networks FX-7TM offering leverages the company’s 7nm: FinFET process to deliver best in class IP and Solutions June 13th, 2017

The Zeiss Global Centre in the School of Engineering at the University of Portsmouth uses Deben µXCT stages to characterise the structural competence of biological structures June 13th, 2017

Govt.-Legislation/Regulation/Funding/Policy

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Nanomedicine

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Learning with light: New system allows optical “deep learning”: Neural networks could be implemented more quickly using new photonic technology June 12th, 2017

Mussels add muscle to biocompatible fibers: Rice University chemists develop hydrogel strings using compound found in sea creatures June 9th, 2017

Making vessels leaky on demand could aid drug delivery:Rice University scientists use magnets and nanoparticles to open, close gaps in blood vessels June 8th, 2017

Discoveries

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Announcements

U.S. Air Force Research Lab Taps IBM to Build Brain-Inspired AI Supercomputing System: Equal to 64 million neurons, new neurosynaptic supercomputing system will power complex AI tasks at unprecedented speed and energy efficiency June 23rd, 2017

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Tools

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Oxford Instruments congratulates Lancaster University for inaugurating the IsoLab, built for studying quantum systems June 20th, 2017

Changing the color of laser light on the femtosecond time scale: How BiCoO3 achieves second harmonic generation June 14th, 2017

Leti Announces Two New Tools for Improving Transportation Comfort, Safety and Efficiency: Wearable Device Measures Stress Responses for Travelers, Pilots and Truck Drivers, While Smartphone App Provides Transit Agencies Broad Data on Transport Modes June 13th, 2017

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

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Mussels add muscle to biocompatible fibers: Rice University chemists develop hydrogel strings using compound found in sea creatures June 9th, 2017

The 2017 Winners for Generation Nano June 8th, 2017

Controlling 3-D behavior of biological cells using laser holographic techniques May 26th, 2017

Nanobiotechnology

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Mussels add muscle to biocompatible fibers: Rice University chemists develop hydrogel strings using compound found in sea creatures June 9th, 2017

Making vessels leaky on demand could aid drug delivery:Rice University scientists use magnets and nanoparticles to open, close gaps in blood vessels June 8th, 2017

Nanobiotix's promising data from Phase I/II head and neck cancer trial presented at ASCO June 5th, 2017

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