• Video 1 Localization of activated Rac1 in anaphase cells expressing wild-type CYK4.
• Video 2 Localization of activated Rac1 and early cytokinesis failure in cells expressing GAP mutant CYK4.
• Video 3 Localization of activated Rac1 and late cytokinesis failure in cells expressing GAP mutant CYK4.