Figure 7
Identification of novel Bach2 protein isoforms. (A) Amino acid sequence of the Bach2 protein isoforms resulting from translation of Bach2 mRNA including exon 5A, 5B, or 4 L. BTB domain sequences are underlined and the sequences different from the canonical BTB domain are in bold letters. (B) Sub-cellular localization of the Bach2 132 aa (encoded by exon 5A including transcript) and 83 aa (encoded by exon 4 L including transcript) isoforms. NIH-3T3 cells were transfected with expression vectors encoding N-terminal FLAG-tagged open reading frames of the Bach2 isoforms. 48 hours after transfection cells were immunostained with anti-FLAG antibody and a TRITC-conjugated secondary antibody. Fluorescence was monitored by epi-fluorescence microscopy. DAPI staining was used to localize the nuclei. Non-transfected NIH3T3 cells served as negative control. (C) Western blot analysis of the Bach2 proteins. HEK-293 cells were transfected with the FLAG-tagged Bach2 expression constructs described in (B) and cellular extracts analyzed by western blotting using an anti-FLAG antibody. Molecular weight markers are indicated to the left.