Featured Research

from universities, journals, and other organizations

How precursors of gene-regulating small RNAs are sorted by cellular machinery

Date:
January 5, 2010
Source:
Cold Spring Harbor Laboratory
Summary:
A team of scientists has determined a hierarchical set of criteria that explain how the molecular precursors of gene-regulating small RNAs are sorted by the cellular machinery.

A team of scientists at Cold Spring Harbor Laboratory (CSHL) has determined a hierarchical set of criteria that explain how the molecular precursors of gene-regulating small RNAs are sorted by the cellular machinery.

Led by Benjamin Czech, a group working in the laboratory of CSHL Professor Gregory Hannon posed the question: can distinct patterns be observed in the process that unfolds when double-stranded RNAs enter the RNAi pathway? Shorthand for RNA interference, RNAi is a biological response to double-stranded RNA that can culminate in the regulation of gene expression. It has been observed in a vast range of organisms ranging from plants to worms to flies to man.

An enzyme called Dicer cuts double-stranded RNAs into smaller double-stranded pieces called duplexes. Czech, Hannon and colleagues propose rules governing the next step in the RNAi pathway, in which duplexes are sorted to proteins called Argonautes which are at the core of a molecular complex called RISC (the RNA-Induced Silencing Complex).

"Only one strand of each duplex is chosen," explains Czech, "and which one makes all the difference. In the fruit flies that we used as models for this series of experiments, the selection of one or another strand effectively determines whether the short RNA will seek out and regulate a gene, or whether it will perform another function such as protecting a cell against a viral invader."

The rules determining how a duplex is processed and sorted are discussed in a paper the team published recently in Molecular Cell. These include the overall arrangement of the nucleotides in the duplex; how many bases are paired; where they're paired and unpaired; and how tightly the ends of the duplex are stuck together.

"These rules for sorting are important for two reasons," according to Hannon, who is also an Investigator of the Howard Hughes Medical Institute. "One is that since small RNAs play critical biological roles in nearly every process, understanding which strands of the small RNAs entering RISC act as regulators of gene expression is critical for our fundamental understanding.

"The rules are also important because scientists are hoping to use small RNAs one day as therapeutics. By understanding the rules by which small RNAs are processed and sorted, we move closer to the goal of being able to manipulate the RNAi pathway, bend it to the purpose of addressing disease."


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. Benjamin Czech, Rui Zhou, Yaniv Erlich, Julius Brennecke, Richard Binari, Christians Villalta, Assaf gordon, Norbert Perrimon and Gregory J. Hannon. Hierarchical Rules for Argonaute Loading in Drosophila. Molecular Cell, 2009; 36 (3): 445 DOI: 10.1016/j.molcel.2009.09.028

Cite This Page:

Cold Spring Harbor Laboratory. "How precursors of gene-regulating small RNAs are sorted by cellular machinery." ScienceDaily. ScienceDaily, 5 January 2010. <www.sciencedaily.com/releases/2010/01/100104101408.htm>.
Cold Spring Harbor Laboratory. (2010, January 5). How precursors of gene-regulating small RNAs are sorted by cellular machinery. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2010/01/100104101408.htm
Cold Spring Harbor Laboratory. "How precursors of gene-regulating small RNAs are sorted by cellular machinery." ScienceDaily. www.sciencedaily.com/releases/2010/01/100104101408.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
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