Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Actin muscles in on DNA transcription


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:

More articles from Life Sciences:

nachricht Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute

nachricht 'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>