Fig. 6. Wild-type Sbf1 and myotubularin are cytoplasmic proteins. (A) Western blot analyses of Sbf1, G6PD and c-Myb performed on nuclear (N) and cytoplasmic (C) fractions prepared from Raji cells show Sbf1 predominantly in the cyoplasmic fraction. (B) Immunohistochemical analysis of Sbf1 in tissue sections using an anti-Sbf1 monoclonal antibody shows specific cytoplasmic staining for Sbf1 in the cerebellum from wild-type (left) but not Sbf1^-/- (right) mice. (C) NIH 3T3 cells were examined by immunofluorescence 48 hours after co-transfection of constructs expressing FLAG-tagged Sbf1 or MTM1. Green fluorescence corresponds to FLAG-tagged Sbf1 or MTM1 staining, which was revealed using primary anti-FLAG and secondary fluorescein isothiocyanate-conjugated antibodies.