CHARACTERIZATION OF THE ION CHANNELS FORMED BY POLIOVIRUS IN PLANAR LIPID-MEMBRANES

The steps in poliovirus infection leading to viral entry and uncoating are not well understood. Current evidence suggests that the virus fir st binds to a plasma membrane-bound receptor present in viable cells, leading to a conformational rearrangement of the viral proteins such t hat the virus crosses the membrane and releases the genomic RNA. The s tudies described in this report were undertaken to determine if poliov irus (160S) as well as one of the subviral particles (135S) could inte ract with membrane's lacking poliovirus receptors in an effort to begi n td understand the process of uncoating of the virus. We report that both forms of viral particles, 160S and 135S, interact with lipid memb ranes and induce the formation of ion-permeable channels in a manner t hat does not require acid pH. The channels induced by the viral partic les 160S have a voltage-dependent conductance which depends on the ion ic composition of the medium. Our findings raise the possibility that viral entry into cells may be mediated by direct interaction of viral surface proteins with membrane lipids.