Navigation Links
Dual systems key to keeping chromosomes intact
Date:3/7/2013

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.

The centromerethe center of the "X" shape of a chromosomecontains 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 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 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 Forburg, a professor of molecular biology at the USC Dornsife College of Letters, Arts and Sciences. "Importantly, all the genes we study have human equivalentsand 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 post-doctoral researcher at UCSF; as well as Ruben C. Petreaca, Amanda Jensen, Ji-Ping Yuan and Marc D. 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 heterocrhomatin, 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.


'/>"/>

Contact: Robert Perkins
perkinsr@usc.edu
213-740-9226
University of Southern California
Source:Eurekalert

Related medicine news :

1. Is it time for regional cardiovascular emergency care systems across the US?
2. Program to coordinate regional systems to speed heart attack care
3. A systems approach to preventing obesity in early life
4. Researchers call for obesity prevention efforts to focus on community-wide systems
5. Cancers with disorganized traffic systems more difficult to treat: U of A research
6. Fitness 4 Home Online Introduces the Saber Strength Adjustable Weight Systems
7. Study looks at efforts to improve local food systems through policy
8. Systems biologist receives $2.5 million Pioneer Award for genome research
9. Students win $100K for 3-D printer to turn waste plastic into composting toilets, rainwater systems
10. In financial ecosystems, big banks trample economic habitats and spread fiscal disease
11. UCAN Selects Defran Systems to Support its Wide Range of Youth and Family Programs
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:9/22/2017)... ... September 22, 2017 , ... PITTSBURGH...Defibrillators are ... saves lives. However, if one isn’t accessible in certain locations, the risk of ... I came up with this idea," said an inventor from Ridgecrest, Calif. , ...
(Date:9/22/2017)... ... September 22, 2017 , ... ... Safe Is Smart Scholarship Sweepstakes.,  , Molli C., a graduate student from Sonora, ... Educational Leadership and Administration at St. Thomas University in Miami, Florida, was selected ...
(Date:9/22/2017)... ... September 22, 2017 , ... ... emergency rooms is celebrating the one year anniversary of its Houston-Fallbrook facility. ... said Dr. Otinwa, Facility Medical Director of First Choice Emergency Room Houston-Fallbrook. “It ...
(Date:9/22/2017)... Diego, CA (PRWEB) , ... September 22, 2017 ... ... offer groceries, wearable, and more products at customers’ doorstep. According to Smart Mart, ... Smart Mart has stated to offer wearable, and customers can find clothing at ...
(Date:9/21/2017)... ... September 21, 2017 , ... Process ... 1:30 p.m. – 3:00 p.m. ET, http://www.fdanews.com/processcapabilityindices      , ... wrong, run afoul of The Quality System Regulation (§820.250), and Devicemakers find themselves ...
Breaking Medicine News(10 mins):
(Date:9/6/2017)... Eli Lilly and Company (NYSE: LLY ) ... and lasmiditan, two investigational treatments for migraine, at the ... place Sept. 7-10 in Vancouver . ... from an open-label study evaluating the safety and effectiveness ... mg) for the prevention of migraine. Galcanezumab is a ...
(Date:9/5/2017)... Sept. 5, 2017 Oramed Pharmaceuticals Inc. (NASDAQ: ... clinical-stage pharmaceutical company focused on the development of oral ... concluded its meeting with the U.S. Food and Drug ... formulation. At the ... pathway for submission of ORMD-0801, would be a Biologics ...
(Date:8/29/2017)... 2017 ivWatch, LLC, the leading provider of continuous monitoring ... has been awarded an Innovative Technology contract from Vizient, Inc., the ... ... in the early detection of peripheral IV infiltration and extravasation events ... The Innovative Technology contract was awarded to ...
Breaking Medicine Technology: