Subcellular localization of the BAL protein.

(A) Fluorescence microscopy of NIH3T3 fibroblasts transfected with an expression vector encoding GFP alone (left) or GFP-BAL (right). Whereas fibroblasts transfected with GFP alone exhibit diffuse primarily cytoplasmic GFP (left), cells transfected with GFP-BAL exhibit mainly nuclear fluorescence. (B) Western blot analysis of subcellular fractions from aggressive B-cell lymphoma transfectants expressing either GFP alone or GFP-BAL. Cytoplasmic and nuclear cell fractions were blotted and probed with GFP antiserum (left panel) or control antibodies directed against known cytoplasmic (αtubulin, right lower panel) and nuclear (retinoblastoma [Rb], right upper panel) proteins. In these B-cell transfectants, GFP alone (approximately 26 kd) was primarily detected in the cytoplasm whereas GFP-BAL (approximately 114 kd) was predominantly found in the nucleus.