RT Journal Article SR Electronic T1 Proteotype profiling unmasks a viral signaling network essential for poxvirus assembly and transcriptional competence JF bioRxiv FD Cold Spring Harbor Laboratory SP 087270 DO 10.1101/087270 A1 Karel Novy A1 Samuel Kilcher A1 Ulrich Omasits A1 Christopher Karl Ernst Bleck A1 Corina Beerli A1 Mohammedyaseen Syedbasha A1 Alessio Maiolica A1 Jason Mercer A1 Bernd Wollscheid YR 2016 UL http://biorxiv.org/content/early/2016/11/11/087270.abstract AB To orchestrate context-dependent signaling programs poxviruses encode two dual-specificity enzymes, the F10 kinase and the H1 phosphatase. These signaling mediators are essential for poxvirus production, yet their substrate profiles and systems level functions remain enigmatic. Using a phosphoproteomic screen of cells infected with wildtype, F10, and H1 mutant viruses we systematically defined the viral signaling network controlled by these enzymes. Quantitative cross-comparison revealed 33 F10 and/or H1 phosphosites within 17 viral proteins. Using this proteotype dataset to inform genotype-phenotype relationships we found that H1-deficient virions harbor a hidden hyper-cleavage phenotype driven by reversible phosphorylation of the virus protease I7 (S134). Quantitative phospho-proteotyping further revealed that the phosphorylation-dependent activity of the viral early transcription factor, A7 (Y367), underlies the transcription-deficient phenotype of H1 mutant virions. Together these results highlight the utility of combining quantitative proteotype screens with mutant viruses to uncover novel proteotype-phenotype-genotype relationships that are masked by classical genetic studies.