Featured Research

from universities, journals, and other organizations

Dual systems key to keeping chromosomes intact

Date:
March 7, 2013
Source:
University of Southern California
Summary:
Scientists have discovered how two different structural apparatuses collaborate to protect repetitive DNA when it is at its most vulnerable -- while it is being unzipped for replication.

Susan Forsburg, professor of molecular biology at the USC Dornsife College of Letters, Arts and Sciences.
Credit: Photo/Eric O'Connell

USC scientists have discovered how two different structural apparatuses collaborate to protect repetitive DNA when it is at its most vulnerable -- while it is being unzipped for replication.

Related Articles


The centromere -- the center of the "X" shape of a chromosome -- contains repeated DNA sequences that are epigenetically coded to attract so-called heterochromatin proteins. This protects the structure to ensure that the chromosomes separate properly.

If the heterochromatin is lost (due to mutations in the cell), the repetitive DNA becomes vulnerable to rearrangements and recombination. This is particularly true during DNA replication, when the DNA is transiently unwound to be copied.

If there are also defects in replication fork proteins that cause this process to be delayed or inefficient, the rearrangements are dramatically increased. This "genome instability" can lead to the loss of genetic information or genetic changes that can lead to cell death or cause cancer.

Susan Forsburg, who led the USC team that conducted the research, used yeast cells to show that simultaneously disrupting both heterochromatin and replication fork proteins caused significant increases in abnormal chromosomes, and in some cases, cell death.

"The insight here is really understanding the mechanism of how these different mutants create a lethal collaboration," said Forsburg, professor of molecular biology at the USC Dornsife College of Letters, Arts and Sciences. "Importantly, all the genes we study have human equivalents -- and mutations of some of these are already linked to cancer."

The research appears online in Cell Reports on March 7. Forsburg worked with Pao-Chen Li, formerly a graduate student at USC and now a postdoctoral researcher at the University of California, San Francisco, as well as Ruben Petreaca, Amanda Jensen, Ji-Ping Yuan and Marc Green, all from USC.

"We already knew epigenetic modifications change gene expression in cancer," Forsburg said. "Now we see a synergistic effect between the structural role of epigenetic modification that creates heterochromatin and replication fork stability."

The next step will be to identify additional components that show this same synergistic effect and to determine what other functions act with heterochromatin to preserve genome stability.

The research was funded by the National Science Foundation and the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of Southern California. The original article was written by Robert Perkins. Note: Materials may be edited for content and length.


Journal Reference:

  1. Pao-Chen Li, RubenC. Petreaca, Amanda Jensen, Ji-Ping Yuan, MarcD. Green, SusanL. Forsburg. Replication Fork Stability Is Essential for the Maintainenance of Centromere Integrity in the Absence of Heterochromatin. Cell Reports, 2013; DOI: 10.1016/j.celrep.2013.02.007

Cite This Page:

University of Southern California. "Dual systems key to keeping chromosomes intact." ScienceDaily. ScienceDaily, 7 March 2013. <www.sciencedaily.com/releases/2013/03/130307123951.htm>.
University of Southern California. (2013, March 7). Dual systems key to keeping chromosomes intact. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2013/03/130307123951.htm
University of Southern California. "Dual systems key to keeping chromosomes intact." ScienceDaily. www.sciencedaily.com/releases/2013/03/130307123951.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins