Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Actin muscles in on DNA transcription

01.11.2004


Overturning a scientific stereotype, researchers at the University of Illinois at Chicago have discovered a new role for a key protein involved in muscle contraction and shown it is present not just in the cytoplasm of cells but in the nucleus as well.



Actin has been pigeonholed as a molecular motor, explains Primal de Lanerolle, professor of physiology and biophysics at UIC. "Whenever cells move or divide, actin is involved, like its partner myosin." "But in the nucleus," de Lanerolle said, "actin acts instead like a binding protein. It recruits other proteins in the very complicated process our bodies use to transcribe DNA segments into messages made of RNA." These messages travel out to the cytoplasm, where they serve as templates for building proteins, including actin itself. "If actin is blocked, transcription can’t begin," de Lanerolle said.

The finding is published in the current issue of Nature Cell Biology and follows an earlier discovery by de Lanerolle and his colleagues that actin’s cohort, myosin, the other compound involved in muscle contraction, is also present in the nucleus.


Transcription occurs in the nucleus in enzyme factories composed of up to 100 proteins -- huge complexes through which lengthy segments of DNA move as each nucleotide is read off to create an RNA strand. The factories are partly rebuilt each time a gene needs to be transcribed. "If the factory were the size of Grand Central Station, then the DNA would stretch from New York to San Francisco, back to New York again, and on to Kansas City," said de Lanerolle.

Part of the factory is a group of proteins that, once assembled, jump-starts transcription. While scientists know a great deal about this pre-initiation complex, as it is called, they still have much to learn about its components and the sequence in which those components are assembled.

As de Lanerolle and his co-workers discovered, actin is one of the proteins in this complex. Its job is to recruit RNA polymerase II, the enzyme that will later detach itself from the complex and proceed on down the DNA string, stitching together the RNA message. "We were looking for a motor, but we found something completely different," de Lanerolle said. He suspects that actin does act as a motor once RNA polymerase II begins transcription, but that has yet to be proved.

"Learning about the precise components and sequence of events in DNA transcription is important because the process is essential to all cellular activity, whether in normal healthy tissues or in diseases like cancer," de Lanerolle said. "The knowledge we gain will one day open up opportunities for intervening when genetic transcription goes awry."

Other authors of the study are Wilma Hofmann, Ljuba Stojiljkovic, Beata Fuchsova, Gabriela Vargas, Evangelos Mavrommatis and Thomas Hope, from UIC; Vlada Philimonenko, Katarina Kysela, and Pavel Hozak from the Institute of Experimental Medicine in the Czech Republic; James Goodrich, from the University of Colorado; and James Lessard, from the Children’s Hospital Research Foundation in Cincinnati, Ohio.

Sharon Butler | EurekAlert!
Further information:
http://www.uic.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>