Featured Research

from universities, journals, and other organizations

Transcription factor DksA polices the intersection of replication and transcription

Date:
May 13, 2010
Source:
Baylor College of Medicine
Summary:
DNA replication, the process by which a strand of DNA is copied during cell proliferation , and DNA transcription, the process by which the message in the DNA is translated into messenger RNA, involve the same "track" or DNA template. What happens when the two mechanisms are on the same track at the same time? Baylor College of Medicine researchers have identified the director -- the transcription factor DksA

DNA replication, the process by which a strand of DNA is copied during cell proliferation , and DNA transcription, the process by which the message in the DNA is translated into messenger RNA, involve the same "track" or DNA template. What happens when the two mechanisms are on the same track at the same time? Baylor College of Medicine researchers have identified the director -- the transcription factor DksA.

Dr. Jue D. (Jade) Wang, assistant professor of molecular and human genetics at Baylor College of Medicine, focuses her attention on replication -- the process by which a strand of DNA is copied during cell proliferation (growth and division).

Dr. Christophe Herman, also an assistant professor of molecular and human genetics at BCM, zeroes in on transcription -- the process by which the message in the DNA is translated into messenger RNA and ultimately the proteins that are workhorses of the cell.

Scientists in the two fields rarely communicate, but the two processes involve the same "track" or DNA template.

"What happens when two machines are on the same track but going in opposite directions?" said Wang. "These two processes are happening at the same time and use the same template."

Combining skills

The two laboratories combined their skills to answer that question and came up with a director -- the transcription factor DksA. A transcription factor is a protein that helps regulates expression (or the level) of gene activity.

A report on their work appears in the current issue of the journal Cell.

"We think this factor is one of the reason there are not more traffic jams," said Wang. "It is there to make sure that the traffic flows."

Director prevents conflict

Their experiments show that DksA acts on the process of transcription directly to prevent conflict between transcription and replication.

"The factor began our collaboration," said Herman. "We saw that it was regulating the process of transcription. It also tags along with RNA polymerase (the enzyme that prompts the process of making a strand of RNA from the DNA strand)."

When it sees the DNA polymerase (an enzyme critical to replication) come along, "it removes the RNA polymerase from the track," said Herman. That allows replication to take place and prevents the two "machines" from colliding.

The two did their work in a form of Escherichia coli (E. coli), a bacterium often used as a model organism in the laboratory. When DksA was not present in the bacteria, the cell was unstable, prompting a DNA damage response from halted replication.

"Stress can promote endogenous DNA damage," said Herman. Starvation is one method of such stress, he said. When DksA is present, it prevents disruption of replication and maintains the integrity of the DNA.

Findings raise questions

Previously, it was thought that the DNA polymerase simply knocked the RNA polymerase out of the way, said Herman.

"That is not the case. You need to have specific factors to remove the RNA polymerase," he said.

The findings raise as many questions as they answer, said Wang. Does the factor work before or after the enzymes collide?

"We don't know the mechanism yet," she said.

Others who took part in this work include Ashley K. Tehranchi, Matthew D. Blankschien, Yan Zhang, Jennifer Halliday, Anjana Srivatsan and Jia Peng, all of BCM.

Funding for this work came from a Human Frontier Young Investigator Grant, the Robert A. Welch Foundation and the National Institutes of Health.


Story Source:

The above story is based on materials provided by Baylor College of Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ashley K. Tehranchi, Matthew D. Blankschien, Yan Zhang, Jennifer A. Halliday, Anjana Srivatsan, Jia Peng, Christophe Herman, Jue D. Wang. The Transcription Factor DksA Prevents Conflicts between DNA Replication and Transcription Machinery. Cell, 2010; 141 (4): 595 DOI: 10.1016/j.cell.2010.03.036

Cite This Page:

Baylor College of Medicine. "Transcription factor DksA polices the intersection of replication and transcription." ScienceDaily. ScienceDaily, 13 May 2010. <www.sciencedaily.com/releases/2010/05/100513123706.htm>.
Baylor College of Medicine. (2010, May 13). Transcription factor DksA polices the intersection of replication and transcription. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2010/05/100513123706.htm
Baylor College of Medicine. "Transcription factor DksA polices the intersection of replication and transcription." ScienceDaily. www.sciencedaily.com/releases/2010/05/100513123706.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
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:
from the past week

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