The ionophore monensin inhibits mouse polyomavirus DNA replication and destabilizes viral early mRNAs

Monensin is a ionophore compound with different biological activities. It r aises the intralysosomal pH, it binds the plasma membranes particularly at the level of the cisternal system of the Golgi apparatus. It causes imbalan ce in the intramembrane ion traffic and inhibits export of secretory protei ns at membrane level. Monensin blocks endocytosis and therefore impedes ent ry of toxic molecules. The drug also inhibits viral proliferation of RNA an d DNA viruses such as vesicular stomatitis, influenza and human polyomaviru ses. In this report we show that monensin effectively abolishes viral DNA r eplication of mouse polyomavirus. Results show that the half life of viral early mRNAs is significantly reduced in the presence of the drug. Therefore we suggest that the reduction of viral DNA synthesis is a consequence of t he reduced intranuclear pool of viral early antigens. (C) 2000 Societe fran caise de biochimie et biologie moleculaire/Editions scientifiques et medica les Elsevier SAS.