Jub-induced phosphorylation of Warts inhibits its activity and recruitment into biomolecular condensates

Biomolecular condensates play important roles in cellular physiology. Within the Hippo signaling pathway, a key regulator of growth and cell fate, condensates formed by upstream scaffolds recruit and promote the activation of the central kinase of the pathway, Warts (Wts)/LATS. Here, we report that the Wts inhibitor Jub also makes condensates that recruit Wts, raising the question of how partitioning of Wts to activating versus inhibitory condensates might be regulated. We address this by showing that Jub also promotes phosphorylation of the N-terminal intrinsically disordered region of Wts, and that N-terminal phosphorylation sites influence both Wts recruitment into condensates and Wts activity. We identify Minibrain and Homeodomain-interacting protein kinase as kinases that promote the phosphorylation of Wts at these sites and that modulate Wts recruitment into condensates and Wts activity in vivo. Our observations identify the modulation of condensate recruitment by phosphorylation of the Wts N terminus as a mechanism for regulating Hippo signaling.