Featured Research

from universities, journals, and other organizations

New mechanism of genomic instability revealed

Date:
August 21, 2011
Source:
NYU Langone Medical Center / New York University School of Medicine
Summary:
Researchers have discovered the cellular mechanisms that normally generate chromosomal breaks in bacteria such as E. coli.

Researchers at NYU School of Medicine have discovered the cellular mechanisms that normally generate chromosomal breaks in bacteria such as E. coli. The study's findings are published in the August 18 issue of the journal Cell.

"This study provides a new explanation on how bacteria generate mutations and adapt to stressors like antibiotics. The study is quite unusual as it touches on several different fields of molecular biology at the same time: replication, transcription, translation and DNA repair," said Evgeny Nudler, PhD, Julie Wilson Anderson Professor of Biochemistry, NYU School of Medicine and co-author of the study.

The study examines the collision of three major cellular moving "machines": replisome -- a protein complex responsible for DNA synthesis, RNA polymerase -- an enzyme responsible for RNA synthesis, and ribosome -- a molecular structure responsible for protein synthesis. Collisions between replisome and RNA polymerase occur frequently in cells because the two machineries share the same DNA track, but the speed of the replisome is much faster than that of RNA polymerase. However, the consequences of such collisions remained unknown.

Researchers designed an experimental system to directly monitor co-directional and head-on collisions between the replisome and RNA polymerase in living cells under various conditions of growth.

Researchers found co-directional collisions lead to DNA double strand breaks (DSBs) or mutations. Importantly, however, such DSBs appear only if the replisome collides with backtracked RNA polymerase.

Backtracking, or backward sliding of RNA polymerase along RNA and DNA, is an intrinsic property of all cellular RNA polymerases from bacteria to humans. Multiple anti-backtracking mechanisms that employ various transcription factors exist in bacteria and nucleus-containing cells, including human cells.

Researchers demonstrated that the cooperation between translating ribosomes and RNA polymerase is central in the maintenance of genomic stability because it prevents backtracking.

The implication of these findings is significant as the ribosome is the primary sensor of cellular metabolism and stress. It has been well established that stress-induced mutagenesis is activated in response to adverse conditions, such as starvation or antibiotics. The development of mutations depends on error-prone DSB repair, which accelerates adaptation to environmental changes, such as acquisition of resistance to antibiotics. In this respect, the backtracking-based mechanism of DSB may account for stress-driven evolution in bacteria.

"Because the organization of replisomes and RNA polymerase is preserved in evolution, the phenomena of backtracking-driven genome instability for E.coli could occur in other organisms as well. It may potentially explain, for example, some cases of chromosomal fragility associated with certain human diseases" said Dr. Nudler.


Story Source:

The above story is based on materials provided by NYU Langone Medical Center / New York University School of Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dipak Dutta, Konstantin Shatalin, Vitaly Epshtein, Max E. Gottesman, Evgeny Nudler. Linking RNA Polymerase Backtracking to Genome Instability in E. coli. Cell, Volume 146, Issue 4, 533-543, 19 August 2011 DOI: 10.1016/j.cell.2011.07.034

Cite This Page:

NYU Langone Medical Center / New York University School of Medicine. "New mechanism of genomic instability revealed." ScienceDaily. ScienceDaily, 21 August 2011. <www.sciencedaily.com/releases/2011/08/110818132227.htm>.
NYU Langone Medical Center / New York University School of Medicine. (2011, August 21). New mechanism of genomic instability revealed. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2011/08/110818132227.htm
NYU Langone Medical Center / New York University School of Medicine. "New mechanism of genomic instability revealed." ScienceDaily. www.sciencedaily.com/releases/2011/08/110818132227.htm (accessed September 3, 2014).

Share This



More Health & Medicine News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 Video provided by AFP
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