Rok localization is regulated positively by RhoGEF2 and negatively by MTs. Rok-YFP localization (A; black/green) in wild-type (wt) and adjacent cells expressing RhoGEF2, RhoGEF2-RNAi, EB1-DN, or Spas marked with Cherry (magenta), and quantitation of Rok-YFP junctional levels (B). Bar, 5 µm. ***, P < 0.0001.