IngentaConnect A vaccinia virus lacking A10L: viral core proteins accumulate on ...

Authors: Rodriguez, Dolores¹; Bárcena, Montserrat²; Möbius, Wiebke; Schleich, Sibylle; Esteban, Mariano¹; Geerts, Willie J. C.²; Koster, Abraham J.²; Griffiths, Gareth³; Locker, Jacomine Krijnse³

Source: Cellular Microbiology, Volume 8, Number 3, March 2006 , pp. 427-437(11)

Publisher: Blackwell Publishing

Abstract:

Summary

The assembly of the intracellular mature virus (IMV) of vaccinia virus (VV), the prototype member of the poxviridae, is poorly understood and controversial. We have previously proposed that the IMV is composed of a continuous double-membraned cisterna derived from the smooth ER, whereby the genome-containing core is enwrapped by a part of this cisterna. In the present study we characterize a mutant virus in which the synthesis of the major core protein A10L can be conditionally expressed. Without A10L, IMVs are not made; immature viruses (IVs) and regularly stacked membrane structures that contain viral DNA, accumulate instead. By immunolabelling of thawed cryo-sections these stacks contain most of the viral core proteins and low levels of viral membrane proteins. Importantly, the stacked membranes could be labelled with antibodies to an ER marker protein, implying that they are derived from this cellular compartment. By electron tomography (ET) on semi-thin cryo-sections we show that the membranes of the stacks are continuous with the membranes of the IVs. Direct continuities with ER cisternae, to which the stacks are tightly apposed, were, however, not unequivocally seen. Finally, ET revealed how the IV membranes separated to become two-membrane profiles. Taken together, this study shows that VV core proteins and the viral DNA can coassemble onto ER-derived membranes that are continuous with the membranes of the IVs.

Document Type: Research article

DOI: 10.1111/j.1462-5822.2005.00632.x

Affiliations: 1: Centro Nacional de Biotecnología, Campus Universidad Autónoma, 28049 Madrid, Spain. 2: Department of Molecular Cell Biology, Faculty of Biology, Padualaan 8, 3584 Utrecht, the Netherlands. 3: European Molecular Biology Laboratory, Cell Biology and Biophysics Programme, Meyerhofstrasse 1, 69117 Heidelberg, Germany.

You have access to the full text article on a website external to Ingentaconnect.

Please click here to view this article on InterScience.

You may be required to register and activate access on InterScience before you can obtain the full text. If you have any queries please contact onlinehelp@oxon.blackwellpublishing.com

A vaccinia virus lacking A10L: viral core proteins accumulate on structures derived from the endoplasmic reticulum