Febrauary 2010

REPLICATION OF DOUBLE-STRANDED RNA GENOME VIRUSES

(Example: Rotavirus)

Rotavirus is a major cause of severe childhood diarrheal disease. The global scope of rotaviral disease was summarized in the first paragraph of an Ocotber 2004 "minireview" by Ramig in the Journal of Virology titled "Pathogenesis of intestinal and systemic rotavirus infection." In this article, the structure and variety of rotaviruses are summarized in the fourth paragraph, and then the complicated physiology of gastrointestinal disease production is covered in detail, with a "model of rotavirus-induced diarrhea" being shown in a figure. Summing up near the end of the review, Ramig states: "The pathophysiology of rotavirus diarrhea is clearly multifactoral. ........ We have learned a great deal of the molecular biology of rotavirus diarrheal disease components, but a great deal of work remains to be done before rotavirus diarrhea induction is completely understood."

 

1. What are the basics of how Rotavirus, with a segmented double-stranded RNA genome, replicates?

All aspects of rotavirus replication take place in the cytoplasm. Here is my basic overview diagram.

 

2. What's known about the complexities of assembly of reovirus virions?

Other reoviridae besides rotavirus have a similar replication mechanism. To get a sense of where things stand on understanding the complex assembly process, let's look at a 2004 research article in the Journal of Virology (Broering et al.) titled "Reovirus nonstructural protein µNS recruits viral core surface proteins and entering core particles to factory-like inclusions." In addition to the abstract, print out Figure 7 from this paper. We will discuss part B of this figure, the "cartoon depicting the factory of a reovirus strain".

 

3. What's known about what happens after the assembling virions emerge from the factory?

There is a minireview by Delmas et al in Virology in October 2004 titled "Different ways to reach the top of a cell. Analysis of rotavirus assembly and targeting in human intestinal cells reveals an original raft-dependent, Golgi-independent apical targeting pathway." Figure 1 in this article shows their model based on recent studies.

 

4. What is a 2010 update?

To be added duriing spring 2010.