The transcription factor NF-κB is maintained as an inactive complex with IκB, which masks its nuclear localization sequence (NLS), in the cytoplasm. In response to appropriate extracellular signals, IκB is phosphorylated and degraded by proteolysis, allowing the import of NF-κB to the nucleus. In contrast, the yeast transcription factor SWI5 is maintained in the cytoplasm by phosphorylation in the vicinity of its nuclear localization sequence. Regulated dephosphorylation exposes the NLS and allows SWI5 to be transported to the nucleus at the appropriate stage of the cell cycle.