Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A social network of human proteins

23.10.2015

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.”


Contact

Dr. Christiane Menzfeld
Max Planck Institute of Biochemistry, Martinsried
Phone: +49 89 8578-2824

Fax: +49 89 8578-3777

Email: menzfeld@biochem.mpg.de

Prof. Dr. Matthias Mann
Max Planck Institute of Biochemistry, Martinsried
Phone: +49 89 8578-2557

Fax: +49 89 8578-2219

Email: mmann@biochem.mpg.de


Original publication
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

More articles from Life Sciences:

nachricht Bad food? How mesozooplankton reacts to blue-green algae blooms
17.01.2019 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Artificially produced cells communicate with each other: Models of life
17.01.2019 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

Im Focus: Mission completed – EU partners successfully test new technologies for space robots in Morocco

Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.

Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...

Im Focus: Programming light on a chip

Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new integrated photonics platform that can...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Artificially produced cells communicate with each other: Models of life

17.01.2019 | Life Sciences

Velcro for human cells

16.01.2019 | Life Sciences

Kiel physicists discover new effect in the interaction of plasmas with solids

16.01.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>