<i>Drosophila</i> USP22/nonstop polarizes the actin cytoskeleton during collective border cell migration

Polarization of the actin cytoskeleton is vital for collective migration cells in vivo. During invasive border cell Drosophila, polarization directly controlled by Hippo signaling complex, which resides at contacts between cluster. Here, we identify, a genetic screen deubiquitinating enzymes involved migration, an essential role nonstop/USP22 expression pathway components expanded and merlin. Loss nonstop function consequently leads to redistribution F-actin polarity determinant Crumbs, loss polarized protrusions, tumbling Nonstop component Spt-Ada-Gcn5-acetyltransferase (SAGA) transcriptional coactivator but SAGA’s histone acetyltransferase module, does not bind or merlin, dispensable migration. Taken together, our results uncover novel roles SAGA-independent may help guide studies other systems where USP22 necessary motility invasion.