Gasz localizes to mitochondria when expressed in somatic cells. (a) Gasz fused on its N-terminus with EGFP was transfected into HeLa cells which were then cultured overnight, fixed, permeabilized, and immunostained to visualize mitochondria using mouse anti-cytochrome c primary antibody and Alexa 647-conjugated goat anti-mouse secondary antibody. Confocal images were obtained using a Leica TCS5 instrument at 63x magnification. All cells expressing Gasz exhibited the same pattern of  localization in multiple experiments, and identical findings were obtained using HA-epitope-tagged Gasz and after transfection into primary mouse embryo fibroblasts and HEK293 and NIH3T3 cell lines (unpublished data). Arrows, transfected cells; asterisk, a nontransfected cell. The insets show a digitally magnified region both merged and with the channels separated. Bar, 7.5 μm. (b) Cartoon schematic for the Gasz protein domain structure. The number scheme indicates the boundaries for the truncated proteins shown in panels (c) and (d). (c, d) Expression and imaging of EGFP-fused Gasz truncated protein fragments shown in panel (b) as described for full-length Gasz in panel (a). Images are ones typical of at least 3 experiments.