Ehrlichia Wnt SLiM ligand mimic deactivates the Hippo pathway to engage the anti-apoptotic Yap-GLUT1-BCL-xL axis.

TRP120 effector has evolved short linear motif (SLiM) ligand mimicry to repurpose multiple evolutionarily conserved cellular signaling pathways, including Wnt, Notch, and Hedgehog. In this investigation, we demonstrate that and recombinant TRP120 deactivate Hippo signaling, resulting in the activation of Hippo transcription coactivator Yes-associated protein (Yap). Moreover, a homologous 6 amino acid (QDVASH) SLiM shared by TRP120 and Wnt3a/5a ligands phenocopied Yap and β-catenin activation induced by rTRP120, and Wnt5a. Similar Hippo gene expression profiles were also stimulated by , rTRP120, SLiM, and Wnt5a. Single siRNA knockdown of Hippo transcription co-activator/factors, Yap, and transcriptional enhanced associate domain (TEAD) significantly decreased infection. Yap activation was abolished in THP-1 Wnt Frizzled-5 (Fzd5) receptor knockout cells (KO), demonstrating Fzd5 receptor dependence. In addition, the TRP120-Wnt-SLiM antibody blocked Hippo deactivation (Yap activation). Expression of anti-apoptotic Hippo target gene (encodes glucose transporter 1; GLUT1) was upregulated by and corresponded to increased levels of GLUT1. Conversely, siRNA knockdown of significantly inhibited infection. Higher GLUT1 levels correlated with increased B cell lymphoma-extra large (BCL-xL) and decreased BCL2-associated X, apoptosis regulator (Bax) levels. Moreover, blocking Yap activation with the inhibitor Verteporfin induced apoptosis that corresponded to significant reductions in GLUT1 and BCL-xL levels and activation of Bax and Caspase-3 and -9. This study identifies a novel shared Wnt/Hippo SLiM ligand mimic and demonstrates that deactivates the Hippo pathway to engage the anti-apoptotic Yap-GLUT1-BCL-xL axis.