title: A small molecule screen in yeast identifies inhibitors targeting protein-protein interactions within the vaccinia virus replication complex.
abstract: Genetic and biochemical data have identified at least four viral proteins essential for vaccinia virus (VACV) DNA synthesis: the DNA polymerase E9, its processivity factor (the heterodimer A20/D4) and the primase/helicase D5. These proteins are part of the VACV replication complex in which A20 is a central subunit interacting with E9, D4 and D5. We hypothesised that molecules able to modulate protein-protein interactions within the replication complex may represent a new class of compounds with anti-orthopoxvirus activities. In this study, we adapted a forward duplex yeast two-hybrid assay to screen more than 27,000 molecules in order to identify inhibitors of A20/D4 and/or A20/D5 interactions. We identified two molecules that specifically inhibited both interactions in yeast. Interestingly, we observed that these compounds displayed a similar antiviral activity to cidofovir (CDV) against VACV in cell culture. We further showed that these molecules were able to inhibit the replication of another orthopoxvirus (i.e. cowpox virus), but not the herpes simplex virus type 1 (HSV-1), an unrelated DNA virus. We also demonstrated that the antiviral activity of both compounds correlated with an inhibition of VACV DNA synthesis. Hence, these molecules may represent a starting point for the development of new anti-orthopoxvirus drugs.
authors.affiliation: Unité de virologie, Institut de Recherche Biomédicale des Armées (IRBA), 24 avenue des Maquis du Grésivaudan, 38702 La Tronche, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Flusin
authors.forename: Laurent
authors.initials: L
authors.lastname: Saccucci
authors.forename: Céline
authors.initials: C
authors.lastname: Contesto-Richefeu
authors.forename: Amel
authors.initials: A
authors.lastname: Hamdi
authors.forename: Carine
authors.initials: C
authors.lastname: Bardou
authors.forename: Thomas
authors.initials: T
authors.lastname: Poyot
authors.forename: André
authors.initials: A
authors.lastname: Peinnequin
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Crance
authors.forename: Pierre
authors.initials: P
authors.lastname: Colas
authors.forename: Frédéric
authors.initials: F
authors.lastname: Iseni
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000302:isolation & purification* / Q000494:pharmacology; D002460:Cell Line; D015608:Cowpox virus / Q000187:drug effects; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006801:Humans; D011485:Protein Binding / Q000187:drug effects; D020798:Two-Hybrid System Techniques; D014616:Vaccinia virus / Q000187:drug effects*; D014764:Viral Proteins / Q000037:antagonists & inhibitors*; D014779:Virus Replication / Q000187:drug effects*; D015003:Yeasts / Q000235:genetics
chemical_list: D000998:Antiviral Agents; D014764:Viral Proteins