Merged screening for human immunodeficiency virus Tat and Rev inhibitors

In addition to "conventional" drug discovery targets used in modern; strate gies, mainly focusing on proteins, recent insights into gene regulation as a novel drug concept have begun to invite the targeting of biomolecular int eractions between proteins and RNA. Because two protein-RNA interactions (T at and trans-activation-responsive element, Rev and Rev-responsive element) are essential for any productive replication of human immunodeficiency vir us, this important human pathogen was used as a model system for our studie s. The design of a fluorescence-based high throughput assay, in which both targets were presented in the same vessel, enabled us to simultaneously int errogate two characteristics of a potential inhibitor: potency of interfere nce and selectivity toward each of the interactions. Although related syste ms have been reported for several DNA binders, an extension into interferen ce with transcription events would open a new dimension of cellular regulat ion. Here we describe the setup of the screening assay for over 110,000 com pounds as well as a primary characterization of identified hits. The assay' s characteristics demonstrate that a microwell-based dual screening system for RNA binders may add a powerful tool to modern drug discovery.