Confocal laser scanning microscopy of cells transfected with GFP-EBNA1 mutants with Ser-to-Ala or Ser-to-Asp substitutions in the NLS or with Ser-to-Ala substitutions in the C-terminal flanking sequence. (A) GFP-EBNA1, (B) GFP-EBNA1(383DPDD), (C) GFP-EBNA1(383APAA), (D) GFP-EBNA1(S383A), (E) GFP-EBNA1(S385A), (F) GFP-EBNA1(S386A), (G) GFP-EBNA1(388AAAAGA). Chromosomal DNA was stained using Hoechst dye 33258. Localization profiles of GFP-EBNA1 mutants along straight lines drawn through the nucleus and cytoplasm are shown to the right of the photographs of transfected cells.