Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surprising ’Remodeling’ Property of Gene Regulation Process

02.08.2004


Much like moving furniture around to create more space, cells dramatically rearrange their entire genome in order to allow the right genes to be turned on at the right time, new research at the University of North Carolina at Chapel Hill shows.

This extensive chromosomal "remodeling" is accomplished by moving DNA packaging structures called nucleosomes to different spots in the genome. Once a nucleosome is moved from a site, the appropriate gene then can be expressed much more efficiently.

The new findings appear online in the journal Nature Genetics. The study will be published in the August print edition.



The UNC researchers also discovered that when a gene needs to be turned off, the cell recruits the nucleosomes back to a particular location in the genome, thus helping to ensure that expression of the gene is stopped.

Nucleosomes are complexes of proteins that were thought to simply bind to genomic DNA and condense it into structures called chromatin that can fit inside a cell’s nucleus. It was historically assumed that nucleosomes were uniformly distributed throughout the genome and that this distribution was unchanging. The new study overturns this assumption, the UNC researchers said. "Except for at a few genes, it was traditionally thought that there was a monotonic organization of chromatin that did not vary throughout the genome," said senior author Dr. Jason Lieb, assistant professor of biology in UNC’s College of Arts and Sciences and a member of the Carolina Center for Genome Sciences. "But chromatin is a dynamic thing - much more dynamic than was once thought."

The study also suggested a new role for the nucleosome as a regulator of gene expression.

"We now know that nucleosomes mark territory," said co-author Dr. Brian Strahl, assistant professor of biochemistry and biophysics in UNC’s School of Medicine. "This chromosomal remodeling allows the work of gene expression to occur."

The study used the yeast genome as an experimental model to determine if chromosomal remodeling actually occurred. "The yeast genome is very simple compared to the human genome, but yeast are quite responsive to their environment," Lieb said.

By varying the food source given to the yeast, the authors demonstrated that the yeast genes required to process new nutrients lost their nucleosomes and were expressed.

They also showed that nucleosomes return to genes that need to be turned off when yeast are subjected to less than optimal growing conditions. This chromosomal remodeling discovered in yeast likely is directly translatable to the more complicated mammalian genome, the researchers said. "The entire machinery required to package DNA and express genes in yeast is very similar to that in humans," Lieb said. "Its application is likely the same in mammalian cells."

The study potentially paves the way for scientists to understand how chromosomal remodeling influences gene expression and regulation in human diseases such as cancer, Strahl said. "This is such a fundamental observation about the genome, but nobody had ever made it before," he added.

Support for the research came from the National Human Genome Research Institute and the National Institute of General Medical Sciences, components of the National Institutes of Health.

Co-authors with Lieb and Strahl are postdoctoral researchers Drs. Cheol-Koo Lee, department of biology; Yoichiro Shibata, biochemistry and biophysics; and Bhargavi Rao, Curriculum in Genetics and Microbiology.

| newswise
Further information:
http://www.unchealthcare.org

More articles from Life Sciences:

nachricht During HIV infection, antibody can block B cells from fighting pathogens
14.08.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht First study on physical properties of giant cancer cells may inform new treatments
14.08.2018 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>