Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Virus rounds up enzymes, disarms plant

02.06.2014

University of Tokyo researchers have described how a plant-virus protein suppresses an important plant defense mechanism that remembers viral genetic information, providing a new target for developing the first-ever chemical against plant viruses that globally cause more than $60 billion of crop losses each year.

Invading viruses carry genetic material that hijacks the host cell's machinery, fooling it into producing proteins and new viruses. All cells from fungi to plants and mammals employ RNA silencing, a cellular process essential for the regulation of gene expression that also functions as an important defense mechanism.


This is a model depicting that plant virus proteins (TGBp1: blue) aggregate and inactivate double-stranded RNA (dsRNA) synthesizing protein complexes (yellow: SGS3/RDR6 bodies).

Credit: Shigetou Namba, The University of Tokyo

Through RNA silencing, plant cells recognize this viral genetic material, remember and copy it so that other cells in the organism can be warned and destroy the virus. Viruses are known to fight back with RNA silencing suppressors, proteins that inhibit this defense mechanism, but how they interfere with the recording of viral genetic information was unknown.

Now, a research team headed by Professor Shigetou Namba and Dr. Yukari Okano in the Graduate School of Agricultural and Life Sciences has shown for the first time that the plant virus protein TGBp1 disarms RNA silencing by causing two enzymes involved in producing copies of viral genetic information to aggregate as inactive clusters in cells surrounded by the virus protein.

The two enzymes are SGS3 and RDR6, which are involved in producing copies of viral genetic information as double-stranded RNA, an essential step in the plant defense process. The researchers demonstrated that TGBp1 interacted with and inhibited the functions of SGS3 and RDR6, and attached fluorescent markers to TGBp1 and SGS3 to show visually that SGS3, which is usually distributed throughout the cell, formed clusters surrounded by TGBp1.

These results suggest that TGBp1 causes the enzymes SGS3 and RDR6 to form clusters, impeding the formation of double-stranded RNA and inhibiting the recording of viral genetic information, thus reducing plant resistance to viral infection.

"We expected that recording viral genetic information would be the most important step in RNA silencing, because if you can't remember the virus, you can't warn the rest of the organism and stop it spreading," explains Professor Namba.

"This would also make it important for the virus to target, but no one had confirmed any viral RNA silencing suppressors targeting this step in plants. Now we are very excited to be the first to do so, and we expect that other plant viral proteins will be found to have similar functions. Recently other researchers have reported that some viruses infecting humans also have RNA silencing suppressors, so this research may also contribute to the development of medicines targeting those viruses."

###

Keywords: RNA silencing, RNA silencing suppressor, double-stranded RNA, plant virus, TGBp1, SGS3, RDR6, plantago asiatica mosaic virus

Article information

Yukari Okano, Hiroko Senshu, Masayoshi Hashimoto, Yutaro Neriya, Osamu Netsu, Nami Minato, Tetsuya Yoshida, Kensaku Maejima, Kenro Oshima, Ken Komatsu, Yasuyuki Yamaji and Shigetou Namba, "In planta recognition of a dsRNA synthesis protein complex by a potexviral RNA silencing suppressor" The Plant Cell 26 (5) May 2014. doi: 10.1105/tpc.113.120535

http://www.plantcell.org/content/early/2014/05/30/tpc.113.120535.abstract

Links

The University of Tokyo
http://www.u-tokyo.ac.jp/en/

Graduate School of Agricultural and Life Sciences
http://www.a.u-tokyo.ac.jp/english/

Laboratory of Plant Pathology
http://papilio.ab.a.u-tokyo.ac.jp/planpath/en/index-en.html

Contact information

Research contact:

Professor Shigetou Namba
Laboratory of Plant Pathology
Graduate School of Agricultural and Life Sciences
The University of Tokyo
1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657
Tel: +81 (0)3-5841-5053
Fax: +81 (0)3-5841-5054
Email: anamba@mail.ecc.u-tokyo.ac.jp

Press officer:

Yoko Takemoto
Public Relations Division
The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654
Tel: +81 (0)3-5841-2031
Fax: +81 (0)3-3816-3913
Email: kouhoukikaku@ml.adm.u-tokyo.ac.jp

Yoko Takemoto | Eurek Alert!

Further reports about: Agricultural Pathology RNA Virus clusters copies enzymes silencing suppressor viruses

More articles from Life Sciences:

nachricht Building a better battery
29.06.2016 | Texas A&M University

nachricht New way out: Researchers show how stem cells exit bloodstream
29.06.2016 | North Carolina State 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: Optical lenses, hardly larger than a human hair

3D printing enables the smalles complex micro-objectives

3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines...

Im Focus: Flexible OLED applications arrive

R2D2, a joint project to analyze and development high-TRL processes and technologies for manufacture of flexible organic light-emitting diodes (OLEDs) funded by the German Federal Ministry of Education and Research (BMBF) has been successfully completed.

In contrast to point light sources like LEDs made of inorganic semiconductor crystals, organic light-emitting diodes (OLEDs) are light-emitting surfaces. Their...

Im Focus: Unexpected flexibility found in odorant molecules

High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!

In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...

Im Focus: 3-D printing produces cartilage from strands of bioink

Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."

Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...

Im Focus: First experimental quantum simulation of particle physics phenomena

Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Conference ‘GEO BON’ Wants to Close Knowledge Gaps in Global Biodiversity

28.06.2016 | Event News

ERES 2016: The largest conference in the European real estate industry

09.06.2016 | Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

 
Latest News

Building a better battery

29.06.2016 | Life Sciences

New way out: Researchers show how stem cells exit bloodstream

29.06.2016 | Life Sciences

Crucial peatlands carbon-sink vulnerable to rising sea levels

29.06.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>