FIGURE 1.

Overexpression and subcellular distribution of HA-Bcl-xL. A, extracts from untransfected (–) or two clones of HA-Bcl-xL stably transfected cell lines (+) were subjected to immunoblotting with Bcl-xL or HA antibody. GAPDH was used as the loading control. Molecular mass standards are indicated. B, KB-3 and KB-3/HA-Bcl-xL cells were untreated or treated with 30 nm or 200 nm vinblastine (VBL), respectively, for the times indicated. Cytosolic and mitochondrial fractions were prepared and subject to immunoblotting for Bcl-xL. Immunoblotting of procaspase 3 and Cox II (Complex IV) were used as markers for cytosolic and mitochondrial subcellular fractions. C, cytosolic extracts, as in panel B, were probed for expression of active caspase-3.