Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Argonautes: A big turn-off for proteins

02.02.2010
Johns Hopkins scientists believe they may have figured out how genetic snippets called microRNAs are able to shut down the production of some proteins.

The issue, they say, is important because the more scientists know about how genes — the blueprints for proteins — are regulated, the more likely they are to figure out how to use that information in treating or preventing diseases linked to such regulation, including cancer.

In both computer and test-tube studies using fruit-fly protein, the Johns Hopkins researchers intensively studied a fairly large protein called Argonaute because it is known to bind to microRNA and ultimately shut down protein production.

"The question was how it did it," says Rachel Green, Ph.D., a Howard Hughes Medical Institute investigator and professor of molecular biology and genetics in the Johns Hopkins University School of Medicine.

Previous studies have been inconclusive about the mechanism by which microRNAs bound to Argonautes prevent the production of protein from a given gene.

In this study, the team discovered that when an Argonaute binds to a microRNA, it then binds more tightly to a messenger RNA thereby sequestering the message from the translation machine known as the ribosome where protein production happens.

Their research appeared in January in Nature Structural & Molecular Biology.

The team set out to characterize Argonautes first using computers to compare their shapes and structures with other proteins. They found striking similarities between Argonaute structures and proteins that happened to exhibit a particular kind of "cooperative binding" known as allostery.

Allostery is a condition in which the binding of one molecule stimulates the binding of a second.

By chopping up Argonaute proteins from fruit flies and testing each piece individually, the team showed that allostery stimulated tenfold the binding of the Argonaute and miRNA complex to messenger RNA.

The scientists speculate that as a result of being bound, the messenger RNA was prevented from doing its job of delivering a gene's instructions to the ribosome that translates them and manufactures proteins. These studies provide new insights into Argonaute protein function, motivating the next series of questions in the field.

"MicroRNAs are all the rage," Green says. "Suddenly, in the last 10 years, there's this whole set of genes and cellular components that we had no idea existed, and they're ubiquitous. They play roles in all manner of development, and Argonautes are the main class of protein involved in regulating them."

The research was supported by funding from the Howard Hughes Medical Institute.

In addition to Green, Sergej Djuranovic, Michelle Kim Zinchenko, Junho K. Hur, Ali Nahvi, Julie L. Brunelle, and Elizabeth J. Rogers, all of Johns Hopkins, were authors of the paper.

On the Web:

http://www.mbg.jhmi.edu/people/profile.asp?PersonID=366
http://www.hhmi.org/research/investigators/greenr_bio.html
http://www.nature.com/nsmb/index.html

Maryalice Yakutchik | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells
21.09.2018 | NMI Naturwissenschaftliches und Medizinisches Institut an der Universität Tübingen

nachricht A one-way street for salt
21.09.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Three NASA missions return first-light data

24.09.2018 | Physics and Astronomy

Brown researchers teach computers to see optical illusions

24.09.2018 | Information Technology

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>