Membrane Permeabilization by Poliovirus Proteins 2B and 2BC

Rafael Aldabe,Angel Barco,Luis Carrasco

doi:10.1074/jbc.271.38.23134

Abstract

Poliovirus infection leads to drastic alterations in membrane permeability late during infection. Transient expression of each nonstructural protein of poliovirus by means of recombinant vaccinia virus encoding the T7 RNA polymerase indicates that proteins 2B and 2BC strongly enhance membrane permeability to hygromycin B in HeLa cells. Almost no effect on expression of proteins 2C, 3A, 3AB, and 3C was found. Deletions and point mutations in 2B and 2BC have identified sequences in 2B involved in membrane permeabilization. Regions located at both ends of 2B are necessary to bring about these permeability alterations. A deletion of 11 amino acids of 2BC at the junction between 2B and 2C, as well as long deletions in 2C encompassing the GTPase motifs of this protein, do not impair the capacity of 2BC to modify the permeability of the membrane. The release of compounds such as choline or uridine from preloaded cells is also augmented by 2B and 2BC expression.

Highlights

Infection of cells by cytolytic animal viruses leads to profound alterations in membrane permeability [1, 2]
The Golgi apparatus is not recognized in poliovirus-infected cells, and numerous membranous vesicles fill most of the cytoplasm at late times of infection [20, 21]
With regard to the picornavirus genes involved in these alterations, it was found recently that 2BC and to a much lower extent 2C induced membrane proliferation when individually expressed in mammalian cells by means of recombinant vaccinia viruses [25, 26]

Summary

Introduction

Infection of cells by cytolytic animal viruses leads to profound alterations in membrane permeability [1, 2]. The inducible expression of each poliovirus nonstructural protein in bacteria led to the suggestion that overexpression of 2B or 3A increased permeability of the bacterial membranes [28].

Results

Conclusion