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 Lethal combination: Drug cocktail turns off the juice to cancer cells
12.12.2018 | Universität Basel

nachricht Smelling the forest – not the trees
12.12.2018 | Universität Konstanz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

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

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New discoveries predict ability to forecast dementia from single molecule

12.12.2018 | Health and Medicine

CCNY-Yale researchers make shape shifting cell breakthrough

12.12.2018 | Physics and Astronomy

Pain: Perception and motor impulses arise in the brain independently of one another

12.12.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>