FIG. 1.

Characterization of CBFα2, CBFβ, CBFβ-SMMHC, and the deletion mutants. (A) Generation of protein products by in vitro translation. [³⁵S]methionine-labeled proteins were produced by in vitro translation, separated by gel electrophoresis, and detected by autoradiography. The intense bands at the bottom of the gel are the free [³⁵S]methionine. (B) Interactions between CBFα2 and the deletion mutants. The protein products shown in panel A were immunoprecipitated with polyclonal antibody α3043, in the presence or absence of cold in vitro-translated CBFα2. (C) Expression of cDNA constructs after transient transfection into NIH 3T3 cells. The Western blot with extracts derived from transiently transfected NIH 3T3 cells was probed with α3043 to detect CBFα2 and EGFP-CBFα2 (lanes 1 to 4). The relevant proteins are shown by arrowheads in lanes 2 and 4. Similarly, the antibody β141.2 was used to identify CBFβ, CBFβ-SMMHC, the deletion proteins, and their GFP fusions by Western blotting of cellular extracts (lanes 5 to 17). Protein molecular mass markers are shown on the right sides of panels B and C.