Identification of the cardiac ISGylome during CVB3 infection. (A) The ISGylome and ubiquitylome in heart tissue of CVB3-infected wild-type (WT), USP18^C61A/C61A, and ISG15^−/− mice were analyzed by LC-MS/MS at T0, T1, and T2 (n = 3 each). (B, C) Heatmap showing non-supervised hierarchical clustering of significantly regulated di-Gly(K) sites at T1 vs. T0 (B) and T2 vs. T0 (C). The number of sites per cluster is indicated in brackets. On the right of each panel, the same heatmap is shown with missing values depicted in grey. (D) Sequence logos of ISGylated K residues and their five surrounding amino acids at T1 and T2 were drawn with iceLogo. (E and F) Gene Ontology enrichment analyses of ISGylated proteins at T1 (E) and T2 (F) was performed. Selected terms are displayed according to their fold enrichment, red meaning high and yellow low enrichment.