High-throughput screening of a GlaxoSmithKline protein kinase inhibitor set identifies an inhibitor of human cytomegalovirus replication that prevents CREB and histone H3 post-translational modification.

To identify new compounds with anti-human cytomegalovirus (HCMV) activity and new anti-HCMV targets, we developed a high-throughput strategy to screen a GlaxoSmithKline Published Kinase Inhibitor Set. This collection contains a range of extensively characterized compounds grouped into chemical families (chemotypes). From our screen, we identified compounds within chemotypes that impede HCMV protein production and identified kinase proteins associated with inhibition of HCMV protein production that are potential novel anti-HCMV targets. We focused our study on a top 'hit' in our screen, SB-734117, which we found inhibits productive replication of several HCMV strains. Kinase selectivity data indicated that SB-734117 exhibited polypharmacology and was an inhibitor of several proteins from the AGC and CMCG kinase groups. Using Western blotting, we found that SB-734711 inhibited accumulation of HCMV immediate-early proteins, phosphorylation of cellular proteins involved in immediate-early protein production (cAMP response element-binding protein and histone H3) and histone H3 lysine 36 trimethylation (H3K36me3). Therefore, we identified SB-734117 as a novel anti-HCMV compound and found that inhibition of AGC and CMCG kinase proteins during productive HCMV replication was associated with inhibition of viral protein production and prevented post-translational modification of cellular factors associated with viral protein production.