Cellular localization of GFP-tagged Tim50a and Tim50. HeLa cells were transfected with GFP-Tim50a (top row) or GFP-Tim50 (bottom row) and the cells were stained with DAPI to define the nucleus. The right panels show the overlay of the GFP signal (green) with the DAPI signal (blue). Note that GFP-Tim50 has extensive cytoplasmic staining but Tim50a is exclusively nuclear. The nuclear signal for GFP-Tim50 was not reported by  and may be caused by overexpression and/or fusion of GFP to the N-terminus of the protein.
Xu et al. BMC Cell Biology 2005 6:29 doi:10.1186/1471-2121-6-29