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 New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>