DEC 20, 2016 6:13 PM PST

New Research May Change Accepted View of Cell Cycle Control

WRITTEN BY: Carmen Leitch

The cells of organisms move through growth stages, duplicating DNA and eventually dividing, and control of that cycle was thought to be understood. The 2001 Nobel Prize in Physiology or Medicine was awarded for the demonstration that the cyclin-dependent kinase complex regulates the cell cycle. New work however, has followed up on some of the unexplained questions remaining in cell cycle control; researchers have discovered that a metabolic oscillator acts as the conductor of cell division. 

A very simple look at the cell cycle, from Wikimedia Commons

Some data has stood at odds with the accepted view; cells can divide in the absence of the cyclin machinery, for one. For another, in cells where the cycle is arrested, proteins of the late cell-cycle keep on oscillating. "But there were signs that [we didn't have] the complete story," said University of Groningen system biologist Matthias Heinemann. "We knew that metabolism often oscillated in synchrony with the cell cycle. So maybe, this was an autonomous control mechanism."

Heinemann looked at yeast cells growing in microfluidic channels so individual cells could be observed under a microscope for several days. The addition of fluorescent markers enabled the measurement of metabolic markers NADH, an electron carrier, and ATP, an energy source. From that, changes in the levels of those molecules that indicated clear oscillations were seen, usually moving along with the cell cycle. Heinemann added, "But we also noticed that occasionally cells did not divide, and that these cells still showed metabolic oscillations."

Molecular Cell 2016 Papagiannakis et al

Metabolism appeared to be oscillating independently of the cell cycle; well fed cells had rapid oscillations, poorly fed cells oscillated slowly. "We argue that metabolism and the cyclin-dependent kinase complex are coupled oscillators, which together orchestrate the growth and division of eukaryotic cells, but when metabolism is slowed down or sped up too much, the cell cycle can't keep up and stops," said Heinemann. The cyclin-dependent kinase complex moves to the rhythm of the metabolic oscillations, until it can't keep up. The graphical abstract from their work, published in Molecular Cell, is shown above.

The researchers suggest a system where the metabolic oscillations push the cyclin-dependent kinase complex through the cycle, controlling the timing of the various cell cycle stages. This new work could change a lot of textbooks. 

"The current view is too narrow and cannot explain why cells still divide when part of the cyclin-dependent kinase complex is removed," commented Heinemann. It is logical that evolution would favor a focus on the workings of metabolism.  "You would expect the earliest cells or proto-cells to have a simple control system to regulate division, and metabolism would be the obvious candidate." This new work could influence clinical research as well. "Most tumor cells have a very high metabolism. Interfering with metabolic processes could be a way to stop them from proliferating."

If you'd like to know more about gene oscillation networks, watch the following MIT lecture.

 

Sources: Science Daily via University of Groningen, NatureMolecular Cell

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
DEC 22, 2019
Genetics & Genomics
DEC 22, 2019
Functional Mini-Livers Made With New Bioprinting Technique
This technique, could be useful in the production of complete organs that can be transplanted into patients....
JAN 11, 2020
Cell & Molecular Biology
JAN 11, 2020
To Save Others, Bacteria Can Self-Destruct When Infected by a Virus
Scientists were studying viruses that infect and kill bacteria as a medicine for bacterial infections over a hundred years ago, and they are a focus of recent research as well....
JAN 20, 2020
Neuroscience
JAN 20, 2020
Ovarian Cancer Protein Accelerates Alzheimer's Neurodegeneration
Around 21,000 people in the US are diagnosed with ovarian cancer every year, while an estimated 5.8 million Americans have Alzheimer’s. Now, research...
FEB 05, 2020
Genetics & Genomics
FEB 05, 2020
'Chromosome Shattering' is Common Across Cancer Types
A type of genetic mutation called chromothripsis was discovered a few years ago in chronic lymphocytic leukemia....
FEB 09, 2020
Cell & Molecular Biology
FEB 09, 2020
Learning More About X Chromosome Inactivation
The X chromosome carries a thousand genes, so in females, one of the X chromosomes must be silenced to avoid serious developmental consequences....
FEB 23, 2020
Cell & Molecular Biology
FEB 23, 2020
A New Class of Bacterial Enzymes is Discovered
Bacterial enzymes can serve many processes, from breaking down pollutants and digesting foods to metabolizing drugs....
Loading Comments...