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 Lipid nanodiscs stabilize misfolding protein intermediates red-handed
18.12.2017 | Technische Universität München

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Error-free into the Quantum Computer Age

A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.

In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...

Im Focus: Search for planets with Carmenes successful

German and Spanish researchers plan, build and use modern spectrograph

Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Single-photon detector can count to 4

18.12.2017 | Information Technology

Quantum memory with record-breaking capacity based on laser-cooled atoms

18.12.2017 | Physics and Astronomy

How much soil goes down the drain -- New data on soil lost due to water

18.12.2017 | Agricultural and Forestry Science

VideoLinks
B2B-VideoLinks
More VideoLinks >>>