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 Enduring cold temperatures alters fat cell epigenetics
19.04.2018 | University of Tokyo

nachricht Full of hot air and proud of it
18.04.2018 | University of Pittsburgh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
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

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>