Complex life is only possible because proteins bind to each other, forming higher-order structures and signal pathways
Scientists at the Max Planck Institute of Biochemistry in Martinsried near Munich and at the MPI of Molecular Cell Biology and Genetics in Dresden have now drawn a detailed map of human protein interactions.
Thousands of human proteins are connected via tens of thousands of distinct interactions in a network (green). If weak interactions are removed, defined local modules emerge (red). Removal of strong interactions has a much smaller effect on network structure (blue). This underlines the relevance of weak interactions for global interconnectedness.
© MPI of Biochemistry
Using a novel mass spectrometric quantification method, the researchers determined the strength of each interaction. “Our data revealed that most interactions are weak, but critical for the structure of the entire network,” explains Marco Hein, first author of the study. The paper has now been published in the Journal Cell.
Proteins are the building blocks and central protagonists of the cell and contribute to all processes of life at the molecular level. They carry out their tasks by binding to each other and building interaction networks. With the help of quantitative mass spectrometry, scientists can determine precisely which proteins interact with each other.
The technology can be described as molecular fishing: One protein is selected as bait. Fishing it out of a complex mixture retrieves all its interaction partners as well, which are then identified by a mass spectrometer. Scientists from Martinsried and Dresden have now analyzed 1,100 such bait proteins in a large-scale project. They mapped a network of over 5,400 proteins, which are connected by 28,000 interactions.
The different interactions have very distinct properties. Some connections are strong and serve a structural role, others are weak and transient, for instance in signal transduction pathways. Measuring the strength of an interaction is very laborious and hence complicated in high throughput studies.
Using a novel strategy, the German scientists established a method of estimating the strength of each interaction indirectly. They measure the copy numbers of all proteins in the cell, and quantify the ratio at which each interactor is retrieved along with its corresponding bait protein. The stronger an interaction, the more of an interactor is recovered.
The study offers a new perspective of the “social network” of human proteins. Researchers can now not only browse the new repository to see which proteins interact with each other. They can also distinguish different types of interactions.
The data reveal that weak interactions dominate the network. “A single weak interaction may seem irrelevant. In their entirety, however, these interactions form the backbone that holds the entire network together,” explains Marco Hein. “This is a property that the network of proteins has in common with the social network in society.”
Dr. Christiane Menzfeld
Max Planck Institute of Biochemistry, Martinsried
Phone: +49 89 8578-2824
Fax: +49 89 8578-3777
Prof. Dr. Matthias Mann
Max Planck Institute of Biochemistry, Martinsried
Phone: +49 89 8578-2557
Fax: +49 89 8578-2219
M.Y. Hein, N.C. Hubner, I. Poser, J. Cox, N. Nagaraj, Y. Toyoda, I.A. Gak, I. Weisswange, J. Mansfeld, F. Buchholz, A.A. Hyman & M. Mann:
A human interactome in three quantitative dimensions organized by stoichiometries and abundances.
Cell, October, 2015 DOI: 10.1016/j.cell.2015.09.053
Dr. Christiane Menzfeld | Max Planck Institute of Biochemistry, Martinsried
New type of photosynthesis discovered
17.06.2018 | Imperial College London
New ID pictures of conducting polymers discover a surprise ABBA fan
17.06.2018 | University of Warwick
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
15.06.2018 | Materials Sciences
15.06.2018 | Ecology, The Environment and Conservation
15.06.2018 | Power and Electrical Engineering