Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

TOPLESS plants provide clues to human molecular interactions

27.07.2015

Scientists at Van Andel Research Institute (VARI) have revealed an important molecular mechanism in plants that has significant similarities to certain signaling mechanisms in humans, which are closely linked to early embryonic development and to diseases such as cancer.

In plants as in animals and humans, intricate molecular networks regulate key biological functions, such as development and stress responses. The system can be likened to a massive switchboard--when the wrong switches are flipped, genes can be inappropriately turned on or off, leading to the onset of diseases.


The tetrameric TOPLESS complex with the EAR motif peptides bound at its repressor-peptide binding grooves. The repressor peptides are shown as a ball presentation.

Credit: Karsten Melcher, Ph.D., Van Andel Research Institute

Now, VARI scientists have unraveled how an important plant protein, known as TOPLESS, interacts with other molecules responsible for turning genes off. The findings in plants provide a general model across species for this type of gene silencing, which is linked to several vital biological functions in humans. The discovery was published today in Science Advances.

"This is really a fundamental discovery--our structure shows the corepressor TOPLESS interacting with key repressor motifs, which constitutes a major component of gene silencing in plants," said Van Andel Research Institute's Karsten Melcher, Ph.D., one of the study's corresponding authors. "Understanding this interaction in plants gives us unique insight into similar pathways in humans that involve these proteins, which are notoriously tough to investigate."

Using a method called X-ray crystallography, the team determined the three- dimensional structure of TOPLESS, both on its own and when linked with other molecules responsible for turning genes off, thereby regulating gene expression. Although these interacting molecules were chosen from different signaling pathways in plants, they all linked up with TOPLESS in the same manner

"This structure will allow us to take a more targeted approach to investigating TOPLESS's counterparts in humans and significantly expands our knowledge base," said VARI's H. Eric Xu, Ph.D., who also is a corresponding author. "We're extremely excited to continue this work to better understand these proteins and how they interact with other molecules in health and disease states."

The new paper is the third in a trio of publications that unveil key components of fundamental molecular processes. Although the new study provides further insight into human molecular pathways, the work also directly describes how components of the molecular switchboard in plants interact to regulate responses to a multitude of stressors, including temperature fluctuations. The new findings follow an earlier Nature paper, which was included in the top ten list of scientific breakthroughs of 2009 by Science magazine, and an earlier Science paper, both of which describe how plants respond to drought and temperature stress. Taken together, the papers not only have implications for developing hardier plants but also for determining molecular structures for components of entire pathways.

Authors include Jiyuan Ke, Honglei Ma, and Xin Gu of VARI and VARI-Shanghai Institute of Materia Medica; Jiayang Li of the Chinese Academy of Sciences; Joseph S. Brunzelle of Northwestern University; and Adam Thelen, now at Michigan State University.

###

Additional background information on TOPLESS and gene regulation:

Gene expression is regulated by both activators and repressors. Although gene repression is thought to be equally important as gene activation for this regulation, relatively little is known about the mechanisms of gene repressors and co-repressors.

TOPLESS functions as a co-repressor and interacts with repressors containing ethylene-responsive element binding factor-associated amphiphilic repression (EAR) motifs. EAR motifs are the most common form of transcriptional repression motifs found in plants and are thought to facilitate stable epigenetic regulation of gene expression via recruitment of chromatin modifiers.

TOPLESS plays important roles in plant development; its name stems from the fact that mutations in TOPLESS can give rise to seedlings in which the shoot is transformed into a second root, hence "topless" seedlings.

In humans, similar proteins also are altered in many types of tumors, and control embryonic development and the development of neurons.

ABOUT VAN ANDEL RESEARCH INSTITUTE:

Van Andel Institute (VAI) is an independent biomedical research and science education organization committed to improving the health and enhancing the lives of current and future generations. Established by Jay and Betty Van Andel in 1996 in Grand Rapids, Michigan, VAI has grown into a premier research and educational institution that supports the work of more than 270 scientists, educators and staff. Van Andel Research Institute (VARI), VAI's research division, is dedicated to determining the epigenetic, genetic, molecular and cellular origins of cancer, Parkinson's and other diseases and translating those findings into effective therapies. The Institute's scientists work in on-site laboratories and participate in collaborative partnerships that span the globe. Learn more about Van Andel Institute or donate by visiting http://www.vai.org. 100% To Research, Discovery & Hope®

Media Contact

Beth Hinshaw Hall
Beth.HinshawHall@vai.org
616-234-5519

http://www.vai.org 

Beth Hinshaw Hall | EurekAlert!

Further reports about: Andel biological functions diseases genes humans molecular interactions motifs pathways proteins

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>