Featured Research

from universities, journals, and other organizations

Messenger RNAs are regulated in far more ways than previously appreciated

Date:
June 27, 2010
Source:
Cold Spring Harbor Laboratory
Summary:
One way of regulating protein levels in cells is to shorten the lifespan of messenger RNAs (mRNAs), intermediary molecules that get translated into proteins. Researchers have now discovered that mRNAs can be targeted for destruction by several modes and molecules, highlighting a previously unanticipated complexity in the control and regulation of the cell's genetic messages.

One way of regulating protein levels in cells is to shorten the lifespan of messenger RNAs (mRNAs). These are intermediary molecules that are first copied from DNA in the cell's nucleus via a process called transcription and then transported into the cell's body to be translated into protein.

A team of molecular biologists from Cold Spring Harbor Laboratory (CSHL) has now discovered that mRNAs can be targeted for destruction by several modes and molecules, highlighting a previously unanticipated complexity in the control and regulation of the cell's genetic messages. Their findings are detailed in a paper that appears in Molecular Cell on June 25th.

"In addition to revealing the surprising diversity of post-transcriptional events that regulate mRNAs, our work also points to new roles for a family of proteins that mediate RNA interference or RNAi," said CSHL Professor and HHMI Investigator Gregory Hannon, Ph.D., who led the team.

In RNAi, tiny bits of RNA that are about 21 "letters" or nucleotides long latch on to longer messenger RNA strands at regions where their nucleotide sequences are complementary. The tiny RNAs, called microRNAs, serve as guides to a family of proteins called Argonautes. The binding of the microRNA-Argonaute complex to its mRNA target triggers its destruction.

In mammals, this destruction has, until now, mostly been attributed to the activation of cellular pathways that destabilize the mRNA molecule, causing it to decay. By using a method that combines computational predictions with experimental testing, Hannon's group has now detected other modes of mRNA destruction that involve cleavage of mRNAs by various catalytic, or slicing, enzymes.

The team, which profiled the entire population of cleaved mRNAs found in mouse embryonic stem cells, has found multiple mRNAs that have undergone "endonucleolytic cleavage" -- i.e. they have been sliced or cleaved (and hence destroyed) by the enzyme Ago2, one of the Argonautes. By sorting through cleaved mRNAs found in cells that lack Ago2 activity, the team has also found evidence that mRNAs also undergo cleavage by enzymes other than Ago2.

"One of these enzymes is another well known RNAi mediator called Drosha, which, like Ago2, also seems to be able to directly cleave its mRNA targets," explains Fedor Karginov, Ph.D., a postdoctoral researcher in Hannon's group. "But we're found many mRNA targets that aren't cleaved either by Ago2 or by Drosha, which suggests that there are other enzymes involved in regulating the life-spans of mRNAs."

"We've long wondered why Ago2's catalytic activity has been conserved in vertebrates -- organisms in which microRNAs can for the most part operate without enzymatic help from Ago2," explains Hannon. "Our new findings of Ago2's direct involvement in mRNA regulation now help explain some of this evolutionary pressure to maintain a catalytically active Ago2 in mammals."


Story Source:

The above story is based on materials provided by Cold Spring Harbor Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Karginov et al. Diverse Endonucleolytic Cleavage Sites in the Mammalian Transcriptome Depend upon MicroRNAs, Drosha, and Additional Nucleases. Molecular Cell, 2010; 38 (6): 781 DOI: 10.1016/j.molcel.2010.06.001

Cite This Page:

Cold Spring Harbor Laboratory. "Messenger RNAs are regulated in far more ways than previously appreciated." ScienceDaily. ScienceDaily, 27 June 2010. <www.sciencedaily.com/releases/2010/06/100625101508.htm>.
Cold Spring Harbor Laboratory. (2010, June 27). Messenger RNAs are regulated in far more ways than previously appreciated. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2010/06/100625101508.htm
Cold Spring Harbor Laboratory. "Messenger RNAs are regulated in far more ways than previously appreciated." ScienceDaily. www.sciencedaily.com/releases/2010/06/100625101508.htm (accessed August 21, 2014).

Share This




More Plants & Animals News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) — An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) — According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) — According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. Video provided by Newsy
Powered by NewsLook.com
Ramen Health Risks: The Dark Side of the Noodle

Ramen Health Risks: The Dark Side of the Noodle

AP (Aug. 21, 2014) — South Koreans eat more instant ramen noodles per capita than anywhere else in the world. But American researchers say eating too much may increase the risk of diabetes, heart disease and stroke. (Aug. 21) 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