Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UW-Madison scientists find a key to cell division

28.05.2004


Discovery may lead to insights into cancer, birth defects, fertility and neurological disorders


CHO cells dividing with isolated midbodies surrounding them. The cells and midbodies are stained with anti-actin (red), anti-tubulin (green) and DAPI (blue). This image shows Chinese hamster ovary cells in the last stages of division. The red outer membrane is complete around each new cell, while the green midbody still remains between them. Isolated midbodies are also pictured in green around the cells to show the organelles in more detail.
Photo by: courtesy Ahna Skop


CHO cells dividing. The cells are stained with anti-actin (red), anti-tubulin (green) and DAPI (blue). This image shows two Chinese hamster ovary cells in the last stages of division. The red outer membrane is complete around each new cell, while the green midbody still remains between them.
Photo by: courtesy Ahna Skop



A cellular structure discovered 125 years ago and dismissed by many biologists as "cellular garbage" has been found to play a key role in the process of cytokinesis, or cell division, one of the most ancient and important of all biological phenomena.
The discovery of the function of the dozens of proteins harbored within this structure - which are necessary for normal cell division - by a team of scientists led by a University of Wisconsin-Madison geneticist was announced in today’s edition of the journal Science.

The discovery promises a better understanding of the role of cell division in the growth and development of all organisms and, critically, of abnormal cell division, when the key proteins fail. These failures can lead to infertility, birth defects, cancer and neurological problems such as Huntington’s and Alzheimer’s diseases.



"Going from one cell to two, or cytokinesis, is one of the most fundamental of cellular events," dating to a time when life evolved from single-celled organisms, explains Ahna Skop, an assistant professor of genetics with the UW-Madison College of Agricultural and Life Sciences. "It applies to all species and organisms, and it is fundamental to the growth and development of all life on this planet."

However, just as cell division is the key to life, failures in the process can lead to certain diseases, says Skop.

"Several diseases are caused by cells that don’t divide properly, or divide out of control, as in cancer," she says. "In addition, proteins that work during cell division may also work in the neurons in our brain or during wound healing, for example. So understanding how cell division works can help us understand how many other specific types of cells function."

With a new understanding of which proteins affect cell division, medical researchers can potentially develop new drugs to prevent cancer and birth defects, treat fertility and neurological disorders, or aide in wound healing, for example.

During the cell cycle, the genetic information the cell contains is copied and segregated into two new cells. During normal division, the outer membrane of the cell pinches in, forming two separate cells. Although a very simple event, scientists had not fully understood the mechanisms or identified the proteins involved in separating the two newly formed cells, says Skop.

As a graduate student at UW-Madison in John White’s laboratory, Skop became interested in an ephemeral cellular feature called the midbody, which forms briefly - lasting only a minute in the cells of some species - during cell division.

"It was identified over 125 years ago by Walther Flemming, but hadn’t been studied much or paid attention to since," she explains. "Most people thought it was cellular garbage."

However, Skop suspected that the midbody was more than an ancient relic with no useful function. She and colleagues used methods developed in the 1980s by Ryoko Kuriyama, then a UW-Madison postdoctoral researcher and now at the University of Minnesota, and Michael Mullins, now at Catholic University, to isolate midbodies from hamster ovary cells. They then analyzed and identified more than 500 proteins contained in the midbodies.

"Proteins are the building blocks of the cell," Skop says. "As the cell divides and a new membrane forms, the proteins found during that time in the cell cycle would be crucial elements in understanding how the process works."

The next step was to inactivate each protein in a developing embryo. If a defect occurred, it would mean that the inactivated protein is essential for normal development.

"We used nematodes, which are small roundworms that are cheaper and quicker to use than mammalian cells, to assess gene function," Skop says. "All but two of the proteins from the mammalian cells were homologous in the nematodes, which allowed us to perform this mutli-organismal approach. The fact that the process is highly conserved across two very different species shows how ancient and conserved the process of cell division is."

The team analyzed 160 key proteins - including 103 not previously known to function in cell division - and found that 58 percent caused cytokinesis defects if they were inactivated.

"The problems ranged from cells where chromosomes failed to separate normally, leaving extra DNA in one of the new cells, as is seen in Down’s syndrome, for example, to cells in which the dividing membrane would begin to form normally and would suddenly retract before the cells could separate," Skop says. "Many of the proteins caused a variety of cell division and division-related defects."


Skop, who also has an appointment with the UW-Madison Medical School, conducted some of this work as a postdoctoral researcher at the University of California, Berkeley. Her co-authors on the paper are Hongbin Liu and John Yates from the Scripps Research Institute, Rebecca Heald from UC Berkeley, and Barbara Meyer from UC Berkeley and the Howard Hughes Medical Institute.

The National Institutes of Health and the state of Wisconsin funded Skop’s work.

Ahna Skop | EurekAlert!
Further information:
http://www.news.wisc.edu/

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

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

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>