Infection of animal cells with picornaviruses results in the accumulation of replication associated membrane bound vesicles and a cessation in the trafficking of integral membrane and secreted proteins. At present little is known about the role of Foot-and-mouth disease virus (FMDV) non-structural proteins in infection, or on trafficking events in cells. In this study we utilise state-of-the-art bioimaging technology and fluorescent protein chimeras to ascertain the effects of expressing FMDV non-structural proteins 2B, 2C, 2BC, 3A and 3AB on cellular organelles, and on the trafficking of vesicular stomatitis virus glycoprotein (VSVG). The expression of protein 2C in cells resulted in a membrane bound reticular distribution that appeared to form novel structures juxtaposing the cell nucleus. In 2C positive cells these novel structures co-distributed with the ER markers ERp60 and DsRedER. The formation of GFP-2C positive structures was visualised in live cells using wide-field microscopy showing structures forming from the peripheral reticular distribution and migrating towards the nucleus. The putative role of microtubules in the formation and movement of these structures was suggested when cells were incubated in the presence of nocodazole. The possible role of protein 2C in FMDV infection is discussed. The formation of 2C novel structures however had no effect on the trafficking of VSVG from the ER to the plasma membrane. Neither did the expression of 2B (which formed similar juxtanuclear structures to 2C), 3A or 3AB. The presence however of 2BC, the precursor of 2B and 2C in infected cells, had the effect of blocking VSVG in the ER by an unknown mechanism. FMDV hasbeen shown previously to down regulate the surface expression of MHC class I on the surface of infected cells (Sanz-Parra et al., 1998), and the results of this study implicate protein 2BC in the inhibitory effects of FMDV infection
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:273320 |
| Date | January 2002 |
| Creators | Howell, Gareth John |
| Publisher | University of Sussex |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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