Fig. 2. Intracellular localization of GFP-tagged Pin1 and GFP-tagged mutant proteins and their localization in nuclear speckles. A, HeLa cells transiently transfected with GFP, GFP-Pin1 (Pin1), GFP-Pin-C113A (C113A), GFP-Pin1-isomerase domain (PPIase), GFP-Pin1-WW domain (WW), and GFP-Pin1-R68,69L (R68,69L) were analyzed for the localization of the tagged proteins. B, colocalization of Pin1 and the Pin1-WW domain with the spliceosome assembly factor, SC-35. HeLa cells transiently transfected with GFP-Pin1 (Pin1), or GFP-WW domain (WW), were inspected for the intracellular localization of GFP, the SC-35 staining (Anti SC-35), and the superimposition of the individual images (Merge).