Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dartmouth Medical School geneticists discover new role for antisense RNA

28.02.2003


Dartmouth Medical School geneticists studying the biological clock have opened yet another window into the role of an unusual form of RNA known as antisense that blocks the messages of protein-encoding genes.



They found that antisense RNA appears to regulate core timing genes in the circadaian clock that drives the 24-hour light-dark cycle of Neurospora, a model organism better known as bread mold.

The results are reported in the February 27 Nature by Drs. Jennifer Loros and Jay C. Dunlap, both DMS professors, and Susan K. Crosthwaite, formerly a postdoctoral fellow at DMS, and Cas Kramer, both of the University of Manchester, England.


Messenger RNA, which has a single-stranded sequence of nucleotides, is called "sense" because it can be decoded to produce a gene product (a protein). Like DNA, this mRNA can form duplexes with a second strand of RNA whose base sequence is complementary to the first strand. The second strand is called the antisense strand because its nucleotide sequence is the complement of "sense" message. When mRNA forms a duplex with a complementary antisense RNA sequence, the message translation is turned off so the sense strand can no longer be decoded to yield a protein product.

As scientists identify more antisense RNAs, they are beginning to realize these might affect a wide variety of processes. The recent findings, write the authors, "provide an unexpected link between antisense RNA and circadian timing."

Studying the development of spores in the bread mold Neurospora, Dunlap and Loros have teased apart the molecular gears that form the basis of most living clocks. Light and dark cycles reset the clocks, they found, the way turning the hands of a clock does. The clock mechanism, a biological oscillator, keeps time through the delicately balanced interplay of the Neurospora clock genes and proteins in a complex of feedback loops.

"We found a long RNA antisense transcript that arises from the frequency gene, known to encode factors important for the operation of the circadian clock in Neurospora," says Dunlap. "The sense transcript encodes proteins that are involved in the feedback loop that is the oscillator in the clock. The antisense transcript runs in the opposite direction, and apparently does not encode a protein, so its actual role is unknown at present. It may simply bock translation, or it may destabilize the sense message. Antisense transcripts are already known, but usually they are quite small, on the order of 20 to 25 bases. This one is quite large, nearly 5,000 bases."

In normal bread mold strains living in the dark, levels of antisense frequency transcripts cycle with respect to the amount of sense frequency transcripts, and they are inducible by light, the researchers determined. However, in strains mutated to abolish induction of antisense frequency RNA by light, the internal clock time was delayed, and resetting of the clock by light was altered.

If similar environmental factors regulate both sense and antisense transcripts, the authors suggest, a role for antisense frequency RNA might be to confer the ability to keep accurate time by limiting the clock response to extremes in the environment. Likewise other antisense RNAs might be involved in maintaining internal stability in other organisms.

DMS Communications | EurekAlert!
Further information:
http://www.dartmouth.edu/

More articles from Life Sciences:

nachricht When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie

nachricht WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

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...

Im Focus: Tracing down linear ubiquitination

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...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short

23.03.2017 | Life Sciences

Researchers use light to remotely control curvature of plastics

23.03.2017 | Power and Electrical Engineering

Sea ice extent sinks to record lows at both poles

23.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>