Featured Research

from universities, journals, and other organizations

Structural insights into inner workings of viral nanomachine

Date:
April 3, 2014
Source:
World Scientific
Summary:
Researchers are using new nanoscale imaging approaches to shed light on the dynamic activities of rotaviruses, important pathogens that cause life-threatening diarrhea in young children. Once a rotavirus enters a host cell, it sheds its outermost protein layer, leaving behind a double-layered particle (DLP). These DLPs are the form of the virus that produces messenger RNA molecules, which are critical for launching the infection.

Captured rotavirus double-layered particles (DLPs) in the midst of producing RNA. The schematic represents an EM Affinity Grid (gray square) coated with adaptor molecules (red and dark blue) that anchor active rotavirus DLPs (yellow) to the Affinity Grid. Cryo-Electron Microscopy (EM) image of actively transcribing DLPs reveals RNA strands (gray strands) emerging from the virus capsid. Three-dimensional image reconstructions of DLPs (light blue) that actively produce RNA reveal strong density within the viral core. Diameter of each reconstruction is ~80 nm.
Credit: Deborah F. Kelly, Virginia Tech Carilion Research Institute, Virginia Tech.

Researchers at the Virginia Tech Carilion Research Institute (VTCRI) are using new nanoscale imaging approaches to shed light on the dynamic activities of rotaviruses, important pathogens that cause life-threatening diarrhea in young children. Once a rotavirus enters a host cell, it sheds its outermost protein layer, leaving behind a double-layered particle (DLP). These DLPs are the form of the virus that produces messenger RNA molecules, which are critical for launching the infection.

Related Articles


Researchers, Deborah Kelly, Ph.D. and Sarah McDonald, Ph.D., both Assistant Professors at VTCRI, acquired molecular snapshots of rotavirus DLPs, in the midst of producing viral RNA, using cryo-Electron Microscopy (cryo-EM). Th e team performing the work also included third year medical students, Joanna Kam and Andrew Demmert, of the Virginia Tech Carilion School of Medicine, and post-doctoral fellow, Justin Tanner, Ph.D.

To get the best possible view of the nanoscale details of active rotavirus DLPs, Kelly developed a technique that permitted visualization of changes in the outermost shell. In conjunction with novel computational approaches, the scientists were also able to detect the internal features of the DLPs, which had not been previously observed. Interestingly, the internal DLP features changed in a manner that corresponded to observable differences in levels of viral messenger RNA production.

These findings provide new structural insights into the mechanics of rotavirus RNA synthesis, which may in turn provide information about how this viral process takes place upon host cell infection. The results appear in the latest edition of the journal Technology.

"What's remarkable about this study is that we were able to see different levels of complexity inside the DLPs that correlated with viral RNA synthesis," said Kelly. "When viruses were ac-tive, their external structures moved dynamically, in a way that became less organized. While at the same time, strong features within their internal cores become more prominent."

A key innovative approach used by the Kelly laboratory has provided a chance to view a wider spectrum of viral structures. By examining the DLPs attached to antibodies on a stable grid surface, researchers were able to view the nanomachines cycling through their natural processes.

Kelly and McDonald also used a new computer algorithm to categorize the DLPs, independently, which avoided user-bias in the experimental calculations. The statistical-based computational ap-proach classified the samples based on levels of RNA production. The results clearly showed that rotavirus DLPs with a less organized outer protein layer had more solid details in their internal cores. These DLPs were also found in the cryo-EM images to be near more RNA strands.

"For many years scientists have been concerned with higher-resolution results and have not paid close attention to the subtle diversity that exists in virus samples," said McDonald, who is also an Assistant Professor of Biomedical Sciences and Pathobiology at the Virginia-Maryland Regional College of Veterinary Medicine. "But that diversity may be indicative of how viruses actually function inside cells. They are not static, but dynamic in nature."

"It's a little counterintuitive," said Kelly, who is also an Assistant Professor of Biological Sciences in Virginia Tech's College of Sciences. "You would imagine that, if biological parts were moving around, then features would dissipate. When these rearrangements occur in such a con-fined space, however, it may potentially lead to a higher level of organization. And the coordinated changes on the outside of viruses seem to enable these processes."

According to Kelly, these results give new insight into the RNA synthetic processes of rotavirus and may prove useful in our understanding of viral biology in general. Improving our understanding of the inner workings of rotavirus, she added, might also provide new targets for the development of treatments for viral-induced diarrheal diseases.


Story Source:

The above story is based on materials provided by World Scientific. Note: Materials may be edited for content and length.


Journal Reference:

  1. Joanna Kam, Andrew C. Demmert, Justin R. Tanner, Sarah M. McDonald, Deborah F. Kelly. Structural dynamics of viral nanomachines. TECHNOLOGY, 2014; 02 (01): 44 DOI: 10.1142/S2339547814500034

Cite This Page:

World Scientific. "Structural insights into inner workings of viral nanomachine." ScienceDaily. ScienceDaily, 3 April 2014. <www.sciencedaily.com/releases/2014/04/140403095509.htm>.
World Scientific. (2014, April 3). Structural insights into inner workings of viral nanomachine. ScienceDaily. Retrieved November 1, 2014 from www.sciencedaily.com/releases/2014/04/140403095509.htm
World Scientific. "Structural insights into inner workings of viral nanomachine." ScienceDaily. www.sciencedaily.com/releases/2014/04/140403095509.htm (accessed November 1, 2014).

Share This



More Plants & Animals News

Saturday, November 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Watch Baby Goose Survive A 400-Foot Cliff Dive

Watch Baby Goose Survive A 400-Foot Cliff Dive

Buzz60 (Oct. 31, 2014) For its nature series Life Story, the BBC profiled the barnacle goose, whose chicks must make a daredevil 400-foot cliff dive from their nests to find food. Jen Markham has the astonishing video. Video provided by Buzz60
Powered by NewsLook.com
World's Salamanders At Risk From Flesh-Eating Fungus

World's Salamanders At Risk From Flesh-Eating Fungus

Newsy (Oct. 31, 2014) The import of salamanders around the globe is thought to be contributing to the spread of a deadly fungus. Video provided by Newsy
Powered by NewsLook.com
Alcoholic Drinks In The E.U. Could Get Calorie Labels

Alcoholic Drinks In The E.U. Could Get Calorie Labels

Newsy (Oct. 31, 2014) A health group in the United Kingdom has called for mandatory calorie labels on alcoholic beverages in the European Union. Video provided by Newsy
Powered by NewsLook.com
Malaria Threat in Liberia as Fight Against Ebola Rages

Malaria Threat in Liberia as Fight Against Ebola Rages

AFP (Oct. 31, 2014) Focus on treating the Ebola epidemic in Liberia means that treatment for malaria, itself a killer, is hard to come by. MSF are now undertaking the mass distribution of antimalarials in Monrovia. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins