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
Maryalice Yakutchik | EurekAlert!
The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine