Fig. 1. Expression of full-length 34 kDa-myc and CT-myc proteins in Dictyostelium. (A,B) Lysates of CT-myc expressing cells (lane 1), wild-type AX-2 (lane 2), and cells expressing full-length 34 kDa-myc (lane 3) were resolved by SDS-PAGE, blotted to nitrocellulose, and probed with monoclonal antibody B2C, which is reactive to native 34 kDa protein (A), or monoclonal antibody 9E10, which is reactive to the myc epitope tag (B). Note that 34 kDa-myc and CT-myc proteins are expressed at levels roughly equivalent to and significantly less than the endogenous 34 kDa protein, respectively. (C) Nucleotide and amino acid sequence at the translational start site of the CT protein. The wild-type sequence (WT), the frame shift (FS) resulting from deletion of an adenosine (arrow), and the alternative ATG methionine codon presumed to initiate synthesis of the CT-myc protein are shown.