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!
Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University
Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Earth Sciences
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences