The influenza A virus endoribonuclease PA-X usurps host mRNA processing machinery to limit host gene expression

Lea Gaucherand; Brittany K. Porter; Summer K. Schmaling; Christopher Harley Rycroft; Yuzo Kevorkian; Craig McCormick; Denys A. Khaperskyy; Marta Maria Gaglia

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/442996 doi: bioRxiv preprint Figure 6 . The X-ORF interactome is enriched for proteins involved in mRNA processing. (A) Schematic diagram of BirA* fusion baits used in BioID analysis of X-ORF interacting proteins. Numbers indicate independent runs employing each construct set, with BirA*-myc and BirA*-X61(4A)-myc as negative controls. Light, medium, and heavy refer to light, medium, or heavy isotope tags. (B) Overlap between proteins identified by mass spectrometry by at least two unique peptides in the three BioID runs. (C) Average relative abundance of 286 proteins identified in at least two BioID experiments plotted as log2 ratio of medium vs. light (x axis, X-ORF / -) and medium vs. heavy (y axis, X-ORF / X61(4A). Green dots represent proteins with >1.5-fold enrichment over both negative controls, blue dots represent proteins with >1.5-fold enrichment over BirA*-myc alone. Black and red open circles indicate proteins that were designated as high-confidence hits (>2.0-fold enriched over BirA*-myc in at least 2 experiments or >1.5-fold enriched over BirA*-myc and BirA*-X61(4A)-myc in all three experiments). Red open circles highlight the two proteins, nucleolin (NCL) and nucleophosmin (NPM1), that were consistently enriched >2.0-fold over both negative controls in all three experiments. (D) STRING protein-protein interaction network for X-ORF BioID high-confidence hits. Apparent nodes were differentially colored (annotations may overlap for individual proteins, only one grouping for each protein was shown for simplicity). (E) Gene ontology (GO) enrichment analysis of X-ORF BioID hits identified by mass spectrometry (black and red circles in C). Fold enrichment and number of proteins are plotted for GO terms with p < 0.05. See also Figure S5 .