Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Molecular structure of the cell nucleoskeleton revealed for the first time

02.03.2017

Using 3D electron microscopy, structural biologists from the University of Zurich succeeded in elucidating the architecture of the lamina of the cell nucleus at molecular resolution for the first time. This scaffold stabilizes the cell nucleus in higher eukaryotes and is involved in organizing, activating and duplicating the genetic material. Diseases such as muscular dystrophy and premature aging, caused by mutations in the lamin gene, the major constituent of the lamina, can now be studied more effectively.

Compared to bacteria, in eukaryotes the genetic material is located in the cell nucleus. Its outer shell consists of the nuclear membrane with numerous nuclear pores. Molecules are transported into or out of the cell nucleus via these pores.


Nuclear lamina: architecture of delicate meshwork made of lamin filaments (filament rod in dark grey, globular domains in red) beneath nuclear membrane (transparent grey) and pore complexes (blue).

Yagmur Turgay, University of Zurich

Beneath the membrane lies the nuclear lamina, a threadlike meshwork merely a few millionths of a millimeter thick. This stabilizes the cell nucleus and protects the DNA underneath from external influences. Moreover, the lamina plays a key role in essential processes in the cell nucleus – such as the organization of the chromosomes, gene activity and the duplication of genetic material before cell division.

Detailed 3D image of the nuclear lamina in its native environment

Now, for the first time, a team of researchers headed by cell biology professor Ohad Medalia from the Department of Biochemistry at UZH has succeeded in elucidating the molecular architecture of the nuclear lamina in mammalian cells in detail. The scientists studied fibroblast cells of mice using cryo-electron tomography.

“This technique combines electron microscopy and tomography, and enables cell structures to be displayed in 3D in a quasi-natural state,” explains Yagmur Turgay, the first author of the study. The cells are shock-frozen in liquid ethane at minus 190 degrees without being pretreated with harmful chemicals, thereby preserving the cell structures in their original state.

“The lamin meshwork is a layer that’s around 14 nanometers thick, located directly beneath the pore complexes of the nuclear membrane and consists of regions that are packed more or less densely,” says Yagmur Turgay, describing the architecture of the nucleoskeleton.

The scaffold is made of thin, threadlike structures that differ in length – the lamin filaments. Only 3.5 nanometers thick, the lamin filaments are much thinner and more delicate than the structures forming the cytoskeleton outside the cell nucleus in higher organisms.

New approach for research on progeria and muscular dystrophy

The building blocks of the filaments are two proteins – type A and B lamin proteins – which assemble into polymers. They consist of a long stem and a globular domain, much like a pin with a head. Individual mutations in the lamin gene elicit severe diseases with symptoms such as premature aging (progeria), muscle wasting (muscular dystrophy), lipodystrophy and damage of the nervous system (neuropathies).

“Cryo-electron tomography will enable us to study the structural differences in the nuclear lamina in healthy people and in patients with mutations in the lamin gene in detail in the future,” concludes Ohad Medalia. According to the structural biologist, this method permits the development of new disease models at molecular level, which paves the way for new therapeutic interventions.

Literature:
Yagmur Turgay, Matthias Eibauer, Anne E. Goldman, Takeshi Shimi, Maayan Khayat, Kfir Ben-Harush, Anna Dubrovsky-Gaupp, K. Tanuj Sapra, Robert D. Goldman, Ohad Medalia. The molecular architecture of lamins in somatic cells. Nature. March 1, 2017. DOI:10.1038/nature21382

Contact:
Prof. Dr. Ohad Medalia
Department of Biochemistry
University of Zurich
Phone: +41 44 635 55 22
E-mail: omedalia@bioc.uzh.ch

Dr. Yagmur Turgay
Department of Biochemistry
University of Zurich
Phone: +41 44 635 55 06
E-mail: y.turgay@bioc.uzh.ch

Weitere Informationen:

http://www.media.uzh.ch/en/Press-Releases/2017/structure-of-the-cell-nucleoskele...

Kurt Bodenmüller | Universität Zürich

More articles from Life Sciences:

nachricht O2 stable hydrogenases for applications
23.07.2018 | Max-Planck-Institut für Chemische Energiekonversion

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Detecting damage in non-magnetic steel with the help of magnetism

23.07.2018 | Materials Sciences

Researchers move closer to completely optical artificial neural network

23.07.2018 | Information Technology

Enabling technology in cell-based therapies: Scale-up, scale-out or program in-place

23.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>