Membrane deformation by one-dimensional (1D) wetting, a physical process driven by the interaction of the plasma membrane with adhesive nanofibers, triggers the formation of filopodium-like plasma membrane protrusions. In these protrusions, F-actin reorganization occurs after membrane deformation. Here, we interrogate the molecular mechanisms underlying F-actin reorganization in such protrusions formed by human primary epithelial and endothelial cells. While generally assumed that filopodium-like protrusions encompass F-actin bundles, as we observed in epithelial cells, cryo-electron tomography unexpectedly revealed a branched F-actin network in 1D wetting protrusions formed by endothelial cells. Combining high resolution photonic microscopy approaches with genetic and drug perturbations, we show that Arp2/3 activity is required for the proper reorganization of F-actin in 1D wetting endothelial protrusions, a process regulated through the local activation of Cdc42 and N-WASP. Our data suggest that F-actin reorganization in response to membrane deformation by 1D wetting is differentially regulated in epithelial versus endothelial cells, possibly impacting a wide range of physiological processes, such as cell migration, adhesion, and microenvironment probing.