By exploiting the DNA of a thermophilic fungus that grows optimally between 50 and 60 degrees Celsius Heidelberg scientists have reconstructed a central piece of the cell's nuclear envelope in the test-tube.
This structure is part of the nuclear pore complex, which mediates the exchange of material between the cell nucleus and its surrounding compartment, the cytoplasm. To achieve their goals, researchers from Heidelberg University and the European Molecular Biology Laboratory (EMBL) sequenced the genome of the thermophilic eukaryote Chaetomium thermophilum and identified all the proteins of the nuclear pore transport channel. This breakthrough enabled them to assemble a long sought-after central pillar of the nuclear pore. The findings reported by Prof. Dr. Ed Hurt and Dr. Peer Bork have been published in „Cell“ (22 July 2011).
A very prominent development in the evolution of a eukaryotic cell was the formation of a nuclear envelope around the genetic information, the chromosomes, which formed a barrier and hindered exchange of material between the nucleus and the cytoplasm. However, nuclear pore complexes have co-evolved as transport channels in the nuclear envelope to allow traffic between these two cellular compartments. Each nuclear pore complex is composed of about 30 different components called nucleoporins or Nups, which exist in many copies so that ca. 500 subunits build up this complex nano-machine.
Previously, the core structure of the nuclear pore complex was unknown, since it was difficult to reconstruct this assembly outside of the cell, due to the instability of isolated nuclear pore components. Thus, Prof. Hurt and his team sought to utilize thermostable nuclear pore building blocks from a thermophilic eukaryote to foster biochemical reconstitution. It is well known that proteins derived from heat-loving bacteria, which can still grow at temperatures above 100 degrees Celsius, are extremely robust. Notably, such exotic organisms also exist in the kingdom of eukaryote life. One example is Chaetomium thermophilum, a filamentous fungus, involved in the decomposition of plant material, a biological process generating heat as high as 70 degrees Celsius.
At Heidelberg University Biochemistry Center, Prof. Hurt and his team have deciphered the entire DNA sequence of the thermophilic fungus consisting of approximately 28 million DNA bases. Dr. Bork and his research group at the European Molecular Biology Laboratory have annotated the genome sequence and identified all the proteins in this organism, more than 7,000. Among them were the 30 Nups of the nuclear pore complex. By using these thermophilic Nups, Ed Hurt's team finally succeeded in reconstituting a central structure of the nuclear pore complex in the test-tube. Prof. Hurt and Dr. Bork are confident that their findings will foster the development of this eukaryotic thermophile as a model organism to study complicated eukaryotic molecular machines.
For more information, go to http://www.uni-heidelberg.de/zentral/bzh/hurt.
Marietta Fuhrmann-Koch | idw
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
21.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
21.08.2017 | Materials Sciences
21.08.2017 | Health and Medicine
21.08.2017 | Materials Sciences