Amiloride derivatives block ion channel activity and enhancement of virus-like particle budding caused by HIV-1 protein Vpu

The Vpu protein of human immunodeficiency virus type I forms cation-selective ion channels and enhances the process of virion budding and release. Mutagenesis studies have shown that the N-terminal transmembrane domain primarily controls both of these activities. Here we report that the Vpu ion channel is inhibited by the amiloride derivatives 5-(N,N-hexamethylene)amiloride and 5-(N,N-dimethyl)amiloride but not by amiloride itself, nor by amantadine. Hexamethyleneamiloride also inhibits budding of virus-like particles from HeLa cells expressing HIV-1 Gag and Vpu proteins. These results confirm the link between Vpu ion channel activity and the budding process and also suggest that amiloride derivatives might have useful anti-HIV-1 properties.