Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Helping to Transport Proteins Inside the Cell

21.11.2018

Researchers from the University of Freiburg have discovered how proteins are transported to the cell’s power stations

The research labs of the associate professor (Privatdozent) Dr. Thomas Becker and Prof. Dr. Nikolaus Pfanner teamed up with several other researchers at the University of Freiburg to discover a mechanism inside cells that transports proteins to the mitochondria. Their research has now been published in the science journal Cell Reports.


This microscopic image shows mitochondria in a yeast cell that are marked with fluorescent dye.

Image: Łukasz Opaliński, Becker research lab

Mitochondria are not only responsible for many vital processes within a cell; they also produce energy for the cell’s metabolism, which is why they are referred to as the cell’s power stations.

When defects occur in their biogenesis and function, this can cause serious diseases in the central nervous system or the heart. In order to function properly, mitochondria are dependent on roughly 1,000 different kinds of proteins, which are imported from the cytosol, the fluid inside the cell.

The ribosomes inside this fluid are the cell’s protein factories that also produce precursor forms of proteins for the mitochondria. These precursor proteins are then escorted by molecular chaperones from the ribosomes to the mitochondria.

Chaperone proteins promote folding of other proteins into their three-dimensional structures. Since the cellular content of chaperones is increased upon heat stress these proteins also termed heat shock proteins (Hsps). The Hsp70 chaperone is especially important for chaperoning precursor proteins into mitochondria.

The translocases of the outer mitochondrial membrane (TOM complex) forms the entry gate for almost all mitochondrial precursor proteins. Specific receptor proteins like Tom22 and Tom70 recognize the incoming precursor proteins. How the precursors are transferred from the cytosolic chaperones to specific TOM receptors remained largely unknown.

Researchers from the collaborative research center “Functional Specificity by Coupling and Modification of Proteins”, the research training group “Transport Across and Into Membranes“, and the cluster of excellence BIOSS Centre for Biological Signalling Studies at the University of Freiburg teamed up to study the role of J-proteins, which are helpers of the Hsp70 chaperones, in the transport of proteins to the mitochondria.

The postdoc Łukasz Opaliński from Thomas Becker's research group demonstrated that the J-protein Xdj1 is involved in the transport of mitochondrial proteins. In collaboration with the group of Prof. Dr. Bettina Warscheid, he determined that Xdj1 binds to the Tom22 receptor. Thereby, Xdj1 promotes the transfer of precursory proteins from the cytosolic chaperones to the TOM complex to initiate their import into the mitochondria.

The researchers also discovered that a second J-protein called Djp1 binds to the Tom70 receptor of the TOM complex, indicating that two different J-proteins associate with two distinct TOM receptors to deliver precursor proteins to the TOM complex.

The results of this study showed that two J-proteins are critical for the selective targeting of mitochondrial precursor proteins to distinct receptor proteins of powerhouse of cell.

Wissenschaftliche Ansprechpartner:

Privatdozent Dr. Thomas Becker
Institute for Biochemistry and Molecular Biology
University of Freiburg
Phone: 0049 (0) 761/203-5243
Email: thomas.becker@biochemie.uni-freiburg.de

Originalpublikation:

Opaliński, Ł., Song, J., Priesnitz, C., Wenz, L.S., Oeljeklaus, S., Warscheid, B., Pfanner, N. and Becker, T. (2018) Recruitment of cytosolic J-proteins by TOM receptors promotes mitochondrial protein biogenesis. Cell Report, in press.

Weitere Informationen:

https://www.pr.uni-freiburg.de/pm-en/press-releases-2018/helping-to-transport-pr...

Rudolf-Werner Dreier | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Heat flow through single molecules detected

19.07.2019 | Physics and Astronomy

Heat transport through single molecules

19.07.2019 | Physics and Astronomy

Welcome Committee for Comets

19.07.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>