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 An evolutionary heads-up – The brain size advantage
22.05.2015 | Veterinärmedizinische Universität Wien

nachricht Endocrine disrupting chemicals in baby teethers
21.05.2015 | Goethe-Universität Frankfurt am Main

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

Im Focus: First electrical car ferry in the world in operation in Norway now

  • Siemens delivers electric propulsion system and charging stations with lithium-ion batteries charged from hydro power
  • Ferry only uses 150 kilowatt hours (kWh) per route and reduces cost of fuel by 60 percent
  • Milestone on the road to operating emission-free ferries

The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...

Im Focus: Into the ice – RV Polarstern opens the arctic season by setting course for Spitsbergen

On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.

RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...

Im Focus: Gel filled with nanosponges cleans up MRSA infections

Nanoengineers at the University of California, San Diego developed a gel filled with toxin-absorbing nanosponges that could lead to an effective treatment for skin and wound infections caused by MRSA (methicillin-resistant Staphylococcus aureus), an antibiotic-resistant bacteria. This "nanosponge-hydrogel" minimized the growth of skin lesions on mice infected with MRSA - without the use of antibiotics. The researchers recently published their findings online in Advanced Materials.

To make the nanosponge-hydrogel, the team mixed nanosponges, which are nanoparticles that absorb dangerous toxins produced by MRSA, E. coli and other...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Mesoporous Particles for the Development of Drug Delivery System Safe to Human Bodies

22.05.2015 | Materials Sciences

Computing at the Speed of Light

22.05.2015 | Information Technology

Development of Gold Nanoparticles That Control Osteogenic Differentiation of Stem Cells

22.05.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>