Figure 5.

Virotrap confirms interaction of S. Typhimurium effector SspH2 with PFN1/2 and potential interaction with other associated actin cytoskeleton components. S. Typhimurium (SL1344) effector SspH2 was subjected to MS-based Virotrap analysis. (A) Significant hits (Limma, p-value < 0.05) are shown in blue and yellow [i.e., for hits defined as “actin-binding” (keyword) or actin, i.e., ACTB]. Proteins uniquely identified in the Virotrap control samples were excluded from the statistical analysis and are not shown in the volcano plot. (B) Gag-SspH2 co-enriched proteins (Limma, p-value < 0.05) are visualized in a STRING interaction network with the known interactors of SspH2 (PFN1 and−2) lined in pink (Table 1). The protein SspH2 interaction network associated with actin (-binding) is shaded in yellow. Significantly enriched proteins disconnected from the networks were not included in the network representation. (C) The BioPlex 3.0 interaction network characterized using C-terminally FLAG-HA-tagged PFN2 by means of anti-HA affinity purification (AP)-MS in HEK293T. Corresponding log2 fold changes of GAG-SspH2 co-enriched proteins are color-coded in the network nodes. VASP did not meet the selection criteria for quantification and ACTA2 was not regulated in the Virotrap dataset.