Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cell Shape Changes during Mitosis

12.02.2013
Heidelberg scientists study transient degradation of an actin regulator

Scientists at the Center for Molecular Biology of Heidelberg University have gained new insight into the process of mitosis in mammalian cells.


Immunofluorescence staining of a cell in early mitosis with normal (right) and with elevated (left) levels of Eps8. The actin cytoskeleton is shown in green and DNA in red. Blue colours depicts a specific marker for mitosis.

Credits: Dr. Achim Werner

Researchers under the direction of Prof. Dr. Frauke Melchior, in collaboration with colleagues from Göttingen, Milan and Memphis, have succeeded in deciphering a heretofore unknown mechanism that plays a key role in cell shape changes during mitosis. They investigated the transient degradation of a protein that regulates specific structures of the mechanical scaffold of the cell, the actin cytoskeleton. The results of the research on this actin regulator were published in the journal “Nature Cell Biology”.

Equally dividing the chromosomes between two daughter cells during mitosis is a multi-step and precisely controlled process. After break-down of the cell nucleus and mitotic spindle formation, the chromosomes pull apart and travel towards the spindle poles. Two cell nuclei are then formed and the cell splits into two daughter cells. According to Prof. Melchior, it has long been known that the cell’s actin cytoskeleton – threadlike cellular structures made up of the structural protein actin – is also a major regulating component of this process. Due to dynamic changes before, during and after the mitosis phase, the actin cytoskeleton contributes to the mechanical requirements for the symmetrical distribution of chromosomes to the two new daughter cells. “We barely understand how and why the actin network of the cell changes, especially in the early phases of mitosis. Of particular interest is how cells assume a round shape when cell division starts and then flatten out again once it ends”, explains Dr. Achim Werner, a key contributing member of Prof. Melchior's research group.

The Heidelberg researchers were now able to show that the transient degradation of an actin regulator in the cell's cytoskeleton, known as Eps8, plays an important role in the mitosis phase. The degradation of Eps8, which only appears to be a “stable” protein, is mediated by a little known Ubiquitin E3 ligase. “If you turn off this degradation mechanism, cell rounding is delayed and the early phases of mitosis slow down. If, however, there is too little Eps8 during the later phase of mitosis, the shape of the cell deforms markedly”, continues Dr. Werner. Thus, precise control of Eps8 levels contributes to the structural changes that eukaryotic cells must undergo to distribute the genetic information correctly to the two daughter cells. “Our work once again demonstrates that controlled protein degradation is a critical component in the regulation of cellular processes”, says Prof. Melchior.

The research was conducted within the framework of the DKFZ-ZMBH Alliance, the strategic cooperation between the German Cancer Research Center (DKFZ) and the Center for Molecular Biology of Heidelberg University (ZMBH). Contributors to the project included researchers from the Max Planck Institute for Biophysical Chemistry in Göttingen and the University Medical Center Göttingen, the FIRC Institute of Molecular Oncology (IFOM) in Milan and the University of Milan, and the Howard Hughes Medical Institute – St. Jude Children’s Research Hospital – in Memphis.
Original publication:
A. Werner, A. Disanza, N. Reifenberger, G. Habeck, J. Becker, M. Calabrese, H. Urlaub, H. Lorenz, B. Schulman, G. Scita & F. Melchior: SCF-Fbxw5 mediates transient degradation of actin remodeller Eps8 to allow proper mitotic progression, Nature Cell Biology (published online 13 January 2013), doi:10.1038/ncb2661

Contact:
Prof. Dr. Frauke Melchior
Center for Molecular Biology of Heidelberg University
Phone +49 6221 54-6804
f.melchior@zmbh.uni-heidelberg.de

Communications and Marketing
Press Office, phone +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>