Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic 'tag team' keeps cells on cycle

09.05.2008
By surveying the activity of thousands of genes at several different time points, researchers at the Duke Institute for Genome Sciences & Policy have uncovered new evidence that a network of influential genes act as a kind of genetic tag team to orchestrate one of the most fundamental aspects of all life: the cell cycle.

“A cell doesn’t want to divide before it is finished copying its DNA or it will end up with broken chromosomes,” a failure with potentially devastating consequences, said Steven Haase, an assistant professor of biology at Duke and member of the IGSP.

He added that although the new insights into the cell cycle were made in single-celled yeast, they may well apply to human cells. “Essentially everything that works in yeast has its functional analog in mammalian cells,” Haase said.

He and his colleagues at the IGSP’s Center for Systems Biology reported their findings in an advanced online publication of the journal Nature on May 7, 2008. The work was supported by the American Cancer Society, the Alfred P. Sloan Foundation, the National Science Foundation and the National Institutes of Health.

... more about:
»Cycle »activity »factor »transcription »yeast

Scientists thought they had already identified all of the major players in keeping cells on track. Earlier studies of small numbers of genes indicated that the carefully timed program of cell growth and division was governed by a handful of genes aptly known as cyclins, along with their partners, the CDKs. (The scientists who first identified these genes received a Nobel Prize for their discovery in 2001).

To see how significant a role cyclins actually have, the Duke team took a look at the bigger picture --an ability only recently made possible by advances in genome technologies, Haase noted.

“It’s a new way of thinking,” he said. “We’ve spent decades on a reductionist approach to science” -- in which researchers typically knock out one or two genes to see what they do. “That method has been phenomenally successful. But now, with genome technologies, we have the opportunity to look at the dynamics of all the genes at the same time.”

In this case, they evaluated the activity of about 6,000 genes over time in mutant yeast cells that lacked functional cyclins.

Under the old models, the parade of gene activity should have come to an abrupt halt without cyclin. Instead, while the yeast cells outwardly showed signs of the disruption and stopped dividing, nearly 70 percent of the periodic genes within them continued to turn on and off right on schedule.

The result doesn’t mean that cyclins aren’t important, Haase said, but there is certainly more to the story.

Haase’s team now thinks that many cell cycle activities are driven by a series of transcription factors (genes that switch other genes on and off), acting one after another. Transcription factor one turns on the genes under its control along with transcription factor two; transcription factor two turns on its set of genes plus transcription factor three, and so on. The last transcription factors in the series then go back to turn on the first, starting the whole cycle over again.

Mathematical models constructed by the team showed that the waves of activity driven by such a network could provide a “very robust oscillator” even without cyclins, Haase said.

In fact, cyclins themselves are among the genes targeted by this transcription-activating tag team. Those cyclins are also known to influence the behavior of the transcription factors in the network. Therefore, Haase suggests that precise control over the cell cycle is ultimately achieved through the joint effort of the transcription factor network and cyclins. In other words, the two keep each other in line, which explains how cell division usually manages to persevere over a wide range of conditions.

“When the cell cycle fails, one of the most devastating outcomes is cancer,” he said. “Obviously, if this layer of control functions in mammalian cells, we’d like to know about it.”

Kendall Morgan | EurekAlert!
Further information:
http://www.duke.edu

Further reports about: Cycle activity factor transcription yeast

More articles from Life Sciences:

nachricht Bioenergy cropland expansion could be as bad for biodiversity as climate change
11.12.2018 | Senckenberg Forschungsinstitut und Naturmuseen

nachricht How glial cells develop in the brain from neural precursor cells
11.12.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
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

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Some brain tumors may respond to immunotherapy, new study suggests

11.12.2018 | Studies and Analyses

Researchers image atomic structure of important immune regulator

11.12.2018 | Health and Medicine

Physicists edge closer to controlling chemical reactions

11.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>