Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Interior of a Cell from a Moving Protein’s Point of View

11.08.2014

Heidelberg scientists develop new methods to measure intracellular protein movement

Numerous obstacles posed by cellular structures hinder protein movements within the cell. Researchers from Heidelberg University and the German Cancer Research Center have succeeded in mapping the intracellular topology by observing proteins in living cells on multiple time and length scales.

By developing a new fluorescence microscopy-based technique, the researchers were able to measure how long it takes proteins to move over distances ranging from 0.2 to 3 micrometres in living cells. Under the direction of Dr. Karsten Rippe, the team analysed the data and developed a mathematical model to reconstruct the intracellular structures. The results of their research were published in “Nature Communications”.

Cellular structures such as membranes, the cytoskeleton and the DNA genome form a dynamic three-dimensional maze inside the cell. Proteins have to find their way through it to reach the sites where they are active. Accordingly, the spatial structure of the cell’s interior is a key factor for protein transport and cell function. “Cellular structures have been visualized in many microscopic studies.

But it is still unclear how the diffusing protein in the cell ‘senses’ this internal network of obstacles,” says Dr. Rippe. To address this question, his team devised a method to infer the cellular topology from the random motion of proteins. The team built their own fluorescence spectroscopy system to observe fluorescent proteins. According to Karsten Rippe, the largest obstacles were densely packed areas of DNA in the cell nucleus.

“A protein in a cell moves much like a marble in a labyrinth game, jockeying its way through the maze,” said Michael Baum, the study’s first author, who pursued the research as part of his PhD thesis at Heidelberg University. The marbles move easily over short distances, but then they encounter an obstacle and are slowed down as they move along.

This results in “stop-and-go” travelling with reduced average speed over longer distances. In their analysis of protein movements, the Heidelberg researchers mapped distances and corresponding translocation times needed for this travel, resulting in the average distance between obstacles. A mathematical model based on this data allowed the scientists to describe the measured movement of the proteins in the cell and reconstruct its topology – at a significantly better resolution than currently possible with light microscopy images, as Dr. Rippe points out.

“The obstacle structure encountered by a protein moving through the cell is porous, much like a sponge,” explains the Heidelberg researcher. Larger proteins were occasionally trapped in this dynamic structure for several minutes. Furthermore, drugs used in chemotherapy or to treat malaria were found to affect the mobility of proteins in the nucleus and make the DNA thicket more permeable. Dr. Rippe and his team now plan to apply their new approach in further experiments at the BioQuant Centre of Heidelberg University and the German Cancer Research Center. They will focus on the interrelation between drug-induced changes in the cell structure and protein transport as well as the disease-related deregulation of this process.

Funding for the research was provided by the Federal Ministry of Education and Research.

Additional information:
http://malone.bioquant.uni-heidelberg.de

Original publication:
M. Baum, F. Erdel, M. Wachsmuth & K. Rippe: Retrieving the intracellular topology from multi-scale protein mobility mapping in living cells. Nature Communications 5, 4494 (24 July 2014), doi: 10.1038/ncomms5494

Contact:
Dr. Karsten Rippe
BioQuant Centre
Phone: +49 6221 54-51376
Karsten.Rippe@bioquant.uni-heidelberg.de

Communications and Marketing
Press Office
Phone: +49 6221 542311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft

Further reports about: BioQuant Cancer Cell DNA Interior Nature Phone fluorescence movements proteins structure structures topology

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>