Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify enzyme that turns on RNA

19.09.2002


Knowing an organism’s genome is good, but knowing what turns on its genes is even better.



Scientists have long searched for triggers that activate ribonucleic acid (RNA), a key component in gene expression. Now, in the Thursday, Sept. 19 issue of the journal Nature, scientists from the University of Wisconsin-Madison report that they have found an enzyme that activates RNA, which could lead to new ways of regulating genetic information.

"One of the big questions in molecular biology is how genes are controlled," says Judith Kimble, a Howard Hughes Medical Institute investigator, a UW-Madison professor of biochemistry and senior author of the paper. "Our finding provides an important piece of the puzzle."


Inside the nucleus of every cell are genes, which are composed of deoxyribonucleic acid (DNA). This genetic information contains all the instructions cells need to make proteins, molecules that enable cells to carry out special functions, such as the transport of oxygen by red blood cells. For these cellular activities to happen, DNA must get copied into RNA, which carry the instructions outside the nucleus to the molecular machinery that makes proteins.

But along the way, things can go awry: If an RNA isn’t activated, Kimble says, "it can get trashed or hidden away. And, if the cell doesn’t have a particular RNA, it won’t have any of the protein the RNA encodes."

Liaoteng Wang, lead author of the article and a graduate student in Kimble’s lab, adds, "a gene won’t do any good if it fails to be expressed."

By studying the embryonic development of the microscopic worm, C. elegans, Kimble and Wang, as well as Marvin Wickens and Christian Eckmann also from UW-Madison’s biochemistry department, identified two proteins - GLD-2 and GLD-3 - that, when bound together to form an enzyme, activate specific RNAs outside the nucleus. This activation would enable the RNA to carry out important steps of germ line, or reproductive, development, such as the formation of sperm or egg cells. In other words, RNA wouldn’t get "trashed."

"People had been looking for this enzyme for a long time," says Kimble. "We were incredibly lucky. We found it serendipitously."

As Kimble explains, Wang and Eckmann had been working independently on the different proteins, both of which are responsible for most stages of germ line development. Wang studied GLD-2 and found that it had a site where reactions could take place, but that it couldn’t bind to an RNA. Eckmann, who studied GLD-3, found that his protein could do just the opposite: it could bind to an RNA, but didn’t have the catalytic site.

"Wang and Eckmann started looking for binding partners for their individual proteins and, amazingly, they found that GLD-2 and GLD-3 bound to each other," says Kimble.

Binding the two proteins together created an enzyme that could not only attach itself to RNA but could also chemically modify the RNA in a specific way that turns it on. And, as Kimble says, "When regulating biologic processes, you don’t want to activate all the RNAs in a cell - you want to activate only the important RNAs at the right time and in the right place."

Researchers have found homologs, or proteins similar to GLD-2, in other organisms, ranging from yeast to humans. Little is known about these homologs, except their amino acid sequences, says Kimble. Proteins similar to GLD-3 have also been found, but only in more complex animals, ranging from worms to humans. Again, how these proteins work remains a mystery.

"More and more organisms’ genomes have been completely sequenced, but sequences don’t tell you the biochemical function of proteins," says Wang. "In this study, we identified the biochemical function of GLD-2, and, since there are proteins in other organisms that have sequences similar to this protein, we can now make more educated guesses about the function of those proteins. It is the idea of ’one stone, many birds.’"

By identifying this enzyme that regulates how genes are expressed in C. elegans, the researchers say it will now be possible for scientists to explore how similar enzymes work in humans, possibly one day leading to new therapies. Says Kimble, "I think this is a big finding for anyone interested in how genes are regulated."


Emily Carlson (608) 262-9772, emilycarlson@facstaff.wisc.edu

Judith Kimble | EurekAlert!

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>