Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Chromosome "Anchors" Organize DNA during Cell Division

Published: Wednesday, January 09, 2013
Last Updated: Wednesday, January 09, 2013
Bookmark and Share
Salk discovery of new role for telomeres in cellular growth may shed light on aging and age-related diseases.

For humans to grow and to replace and heal damaged tissues, the body's cells must continually reproduce, a process known as "cell division," by which one cell becomes two, two become four, and so on. A key question of biomedical research is how chromosomes, which are duplicated during cell division so that each daughter cell receives an exact copy of a person's genome, are arranged during this process.

Now, scientists at the Salk Institute have discovered a new characteristic of human cell division that may help explain how our DNA is organized in the nucleus as cells reproduce. They found that telomeres, molecular caps that protect the ends of the chromosomes, move to the outer edge of the cell's nucleus after they have been duplicated.

While the implications of this spatial reorganization of telomeres are not yet clear, the findings may shed light on how our genes are regulated and how gene expression programs are altered during cell division, an important step in understanding aging and diseases that stem from genetic mutations, such as cancer.

"What we discovered is that telomeres not only protect our chromosomes, they also help organize our genetic material in the nucleus," says Jan Karlseder, a professor in Salk's Molecular and Cell Biology Laboratory and the Donald and Darlene Shiley Chair. "This is important, because the three-dimensional position of DNA in the nucleus influences gene expression profiles and how the genome morphs over time."

Telomeres, a combination of proteins and DNA, are crucial in DNA replication, tumor suppression and aging. Every time a primary human cell divides, its telomeres get shorter, until critically short telomeres lead cells to self-destruct. Much of Karlseder's research has focused on understanding telomere dynamics in order to develop ways to influence the aging process, and as a result, restrict cancer cell growth.

In addition to exploring the involvement of telomeres in premature aging diseases and interactions between the DNA damage machinery and telomeres, Karlseder studies the role of telomeres during the cell cycle. Previous studies on human cells have shown that telomeres change positions during cell division, suggesting they might also play a role in organizing DNA in the nucleus. But these studies provided only isolated snapshots of telomeres at various stages of the cell cycle.

In their new study, the Salk researchers used advanced time-lapse live-cell confocal microscopy to track telomere movement in real time throughout the cell cycle. They followed the telomeres for 20 hours in living cells by labeling them with molecules that glowed under the microscope. They also recorded the movement of chromatin, a combination of DNA and proteins that forms chromosomes.

The scientists found that the telomeres moved to the outer periphery of the nuclear envelope of each daughter cell nucleus as they assemble after mitosis, the stage of cell division during which the cell's DNA is duplicated to provide each daughter cell with its own copy. By exploring the underlying molecular pathways, the researchers determined that interactions between two proteins, RAP1 and Sun1, seem to tether the telomeres to the nuclear envelope. Sun1 alone was also capable of attracting the telomeres to the nuclear envelope, suggesting the protein is essential for the process and that other elements might be able to replace RAP1 during tethering.

"The tethering of telomeres to the nuclear envelope may serve as an anchor point to reorganize chromatin after each cell division, so that our DNA is correctly situated for gene expression," Karlseder says. "This tethering could also play a role in the maintenance of telomeres, thereby influencing aging, cancer development and other disorders associated with DNA damage. We plan to explore these possibilities in future experiments."


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,500+ scientific posters on ePosters
  • More Than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Epigenetic Variations Between Tissues
A Salk Institute-led team has generated a map of the human methylome, gaining insight into patterns of DNA methylation of various tissues.
Wednesday, June 03, 2015
New Stem Cell May Overcome Hurdles for Regenerative Medicine
Scientists have discovered a novel type of pluripotent stem cell capable of developing into any type of tissue whose identity is tied to their location in a developing embryo.
Monday, May 11, 2015
Vital Step in Stem Cell Growth Revealed
Salk scientists' finding could aid regenerative and cancer therapies.
Thursday, May 07, 2015
Gene-Editing Technique Offers Hope For Hereditary Diseases
Salk scientists use molecular "scissors" to eliminate mitochondrial mutations in eggs and embryos.
Monday, April 27, 2015
Cellular Scissors Chop up HIV Virus
Salk scientists re-engineered the bacterial defense system CRISPR to recognize HIV inside human cells and destroy the virus, offering a potential new therapy.
Thursday, March 12, 2015
Powerful Method To Speed Cancer Drug Discovery Unveiled
The new method lets researchers identify weak and previously undetectable interactions between proteins inside living cells.
Monday, November 24, 2014
Salk Scientists Discover a Key to Mending Broken Hearts
Researchers regenerate and heal mouse hearts by using the molecular machinery the animals had all along.
Wednesday, November 12, 2014
Turning Human Skin Cells Into Immune-Fighting White Blood Cells
The fast and safe technique developed at the Salk Institute circumvents problems that have hindered regenerative medicine.
Friday, September 12, 2014
No Extra Mutations in Modified Stem Cells, Study Finds
New results ease previous concerns that gene-editing techniques-used to develop therapies for genetic diseases-could add unwanted mutations to stem cells.
Saturday, July 12, 2014
Salk Institute Receives $3M Gift for Ageing Research
The gift from the Glenn Foundation for Medical Research will allow the Institute to continue conducting research to understand the biology of normal human aging and age-related diseases.
Friday, May 23, 2014
Circadian Clock Gene Linked to Eating Schedule
Research from the Salk Institute has shown that mutations in the circadian genes could drive night eating syndrome.
Friday, May 23, 2014
New Stem Cell Research Points to Early Indicators of Schizophrenia
Salk scientists show fundamental differences in early neurons from patients with schizophrenia, supporting the theory that risk for the disease may begin in the womb.
Wednesday, May 14, 2014
Salk Institute and Stanford Lead New $40M Stem Cell Genomics Center
Collaborative research center will bridge genomics and stem cell projects to find new therapies.
Sunday, February 02, 2014
Salk Scientists Discover more Versatile Approach to Creating Stem Cells
New method should hasten promise of regenerative medicine.
Wednesday, July 24, 2013
Salk Researchers Identify Potential Biomarker for Cancer Diagnosis
Findings of disrupted micronuclei may prove to be a valuable tool for detecting cancer.
Friday, July 12, 2013
Scientific News
The Changing Tides of the In Vitro Diagnostics Market
With the increasing focus in personalized medicine, diagnostics plays a crucial role in patient monitoring.
Immunotherapy Agent Benefits Patients with Drug-Resistant Multiple Myeloma in First Human Trial
Daratumumab proved generally safe in patients, even at the highest doses.
Low-level Arsenic Exposure Before Birth Associated with Early Puberty in Female Mice
Study examine whether low-dose arsenic exposure could have similar health outcomes in humans.
Inciting an Immune Attack On Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
‘Mutation-Tracking’ Blood Test for Breast Cancer
Scientists have developed a blood test for breast cancer able to identify which patients will suffer a relapse after treatment, months before tumours are visible on hospital scans.
Cellular Contamination Pathway for Heavy Elements Identified
Berkeley Lab scientists find that an iron-binding protein can transport actinides into cells.
Intensity of Desert Storms May Affect Ocean Phytoplankton
MIT study finds phytoplankton are extremely sensitive to changing levels of desert dust.
Common ‘Heart Attack’ Blood Test May Predict Future Hypertension
Small rises in troponin levels may have value as markers for subclinical heart damage and high blood pressure.
LaVision BioTec Reports on the Neuro Research on the Human Brain After Trauma
Company reports on the work of Dr Ali Ertürk from the Institute for Stroke and Dementia Research at LMU Munich.
NIH Study Shows No Benefit of Omega-3 Supplements for Cognitive Decline
Research was published in the Journal of the American Medical Association.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!