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.
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
Dr. Karsten Rippe
Phone: +49 6221 54-51376
Communications and Marketing
Phone: +49 6221 542311
Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft
New switch decides between genome repair and death of cells
27.09.2016 | University of Cologne - Universität zu Köln
A blue stoplight to prevent runaway photosynthesis
27.09.2016 | National Institute for Basic Biology
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...
27.09.2016 | Event News
23.09.2016 | Event News
20.09.2016 | Event News
27.09.2016 | Life Sciences
27.09.2016 | Physics and Astronomy
27.09.2016 | Life Sciences