MEMBRANE PERMEABILIZATION BY POLIOVIRUS PROTEINS 2B AND 2BC

Poliovirus infection leads to drastic alterations in membrane permeabi lity 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 enh ance membrane permeability to hygromycin B in HeLa cells, Almost no ef fect on expression of proteins 2C, 3A, 3AB, and 3C was found. Deletion s and point mutations in 2B and 2BC have identified sequences in 2B in volved in membrane permeabilization. Regions located at both ends of 2 B are necessary to bring about these permeability alterations. A delet ion of 11 amino acids of 2BC at the junction between 2B and 2C, as wel l as long deletions in 2C encompassing the GTPase motifs of this prote in, do not impair the capacity of 2BC to modify the permeability of th e membrane. The release of compounds such as choline or uridine from p reloaded cells is also augmented by 2B and 2BC expression.