Featured Research

from universities, journals, and other organizations

Viruses Are Sneakier Than We Thought

Date:
May 27, 2009
Source:
Public Library of Science
Summary:
Of central importance for viruses is the ability to commandeer cellular gene expression machinery. Several human herpes viruses put the breaks on normal cellular gene expression to divert the associated enzymes and resources towards their own viral genes. Kaposi's sarcoma-associated herpes virus, which causes several AIDS-associated cancers, has now been shown to do this in an unexpected way, using a process that is normally protective, called polyadenylation.

Viruses are molecular marauders, plundering cells for the resources they need to multiply. Of central importance for viruses is the ability to commandeer cellular gene expression machinery. Several human herpesviruses put the breaks on normal cellular gene expression to divert the associated enzymes and resources towards their own viral genes. Kaposi's sarcoma-associated herpesvirus (KSHV), which causes several AIDS-associated cancers, has now been shown to do this in an unexpected way, using a process that is normally protective, called polyadenylation.

Related Articles


Cells decode genetic information in a process called transcription, during which the DNA is unzipped and read by enzymes. The product of this process is a piece of messenger RNA, which then emerges from the cell's nucleus (the section of the cell containing DNA) into the cell cytoplasm (the main cellular compartment) and is translated there into the protein corresponding to the DNA's message. Polyadenylation is the process whereby Poly(A) tails are added to messenger RNAs (mRNAs) in the nucleus before they are transported into the cytoplasm. These tails serve several purposes, including protecting the messages from degradation and enhancing the translation to protein. The effects of KSHV on cells was known to be caused by one of it's proteins – called SOX – but how the protein influences host cells transcription process has previously been unclear.

In a study published in this week's issue of PLoS Biology, researchers at UC Berkeley found that the presence of SOX led to an unexpected increase in the length of cellular mRNA poly(A) tails. Mutant KSHV viruses that can't make SOX protein are unable to block cellular gene expression. SOX mutants fail to increase poly(A) tail length. This suggests that the virus uses a process normally involved in enhancement of gene expression to instead inhibit gene expression.

"We suspect that by aberrantly lengthening the poly(A) tails, the virus is sending the cell a signal that something is wrong with its messages and as a consequence they are held back in the nucleus," says Dr. Britt Glaunsinger, one of the researchers involved in this study. Indeed, similar results have been observed in yeast when mRNAs are improperly made or cannot traffic appropriately.

The researchers showed that SOX has more than one trick to play on cells - as well as preventing the export of new cellular mRNAs, SOX targets the existing messages that were made in a cell before the KSHV could turn on its SOX protein. mRNA poly(A) tails are normally bound by the cell's poly(A) binding protein (PABP), which helps guard them from degradation and facilitates their translation into protein. During KSHV infection, however, SOX removes PABP from the cytoplasm and causes it to instead accumulate in the nucleus. PABP re-localization correlates with destruction of cytoplasmic mRNA in SOX-expressing cells, perhaps because these transcripts have been 'stripped' of an important protector. "I find it fascinating that this single viral protein targets a key mRNA stabilizing element from two different angles to block cellular gene expression," says Glaunsinger. "It's yet another example of how viruses have evolved to interface so exquisitely with their hosts."

This research was supported by a Howard Temin Career Development Award and a Burroughs Wellcome Fund Investigators in the Pathogenesis of Infectious Disease Award to BG. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lee et al. Aberrant Herpesvirus-Induced Polyadenylation Correlates With Cellular Messenger RNA Destruction. PLoS Biology, 2009; 7 (5): e1000107 DOI: 10.1371/journal.pbio.1000107

Cite This Page:

Public Library of Science. "Viruses Are Sneakier Than We Thought." ScienceDaily. ScienceDaily, 27 May 2009. <www.sciencedaily.com/releases/2009/05/090526202724.htm>.
Public Library of Science. (2009, May 27). Viruses Are Sneakier Than We Thought. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/2009/05/090526202724.htm
Public Library of Science. "Viruses Are Sneakier Than We Thought." ScienceDaily. www.sciencedaily.com/releases/2009/05/090526202724.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nanoscale Sensor Could Help Wine Producers and Clinical Scientists

Nanoscale Sensor Could Help Wine Producers and Clinical Scientists

Reuters - Innovations Video Online (Jan. 30, 2015) A nanosensor that mimics the oral effects and sensations of drinking wine has been developed by Danish and Portuguese researchers. Jim Drury saw it in operation. Video provided by Reuters
Powered by NewsLook.com
Dog-Loving Astronaut Wins Best Photo of 2015

Dog-Loving Astronaut Wins Best Photo of 2015

Buzz60 (Jan. 30, 2015) Retired astronaut and television host, Leland Melvin, snuck his dogs into the NASA studio so they could be in his official photo. As Mara Montalbano (@maramontalbano) shows us, the secret is out. Video provided by Buzz60
Powered by NewsLook.com
U.S. Wants to Analyze DNA from 1 Million People

U.S. Wants to Analyze DNA from 1 Million People

Reuters - US Online Video (Jan. 30, 2015) The U.S. has proposed analyzing genetic information from more than 1 million American volunteers to learn how genetic variants affect health and disease. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Rarest Cat on Planet Caught Attacking Monkeys on Camera

Rarest Cat on Planet Caught Attacking Monkeys on Camera

Buzz60 (Jan. 30, 2015) An African Golden Cat, the rarest large cat on the planet was recently caught on camera by scientists trying to study monkeys. The cat comes out of nowhere to attack those monkeys. Patrick Jones (@Patrick_E_Jones) has the rest. 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


Plants & Animals

Earth & Climate

Fossils & Ruins

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