Expression and characterization of a protein encoded by the human c-myc exon 1 in Escherichia coli

Our previously reported data from DNA sequence studies of the c-myc locus show that the human c-myc exon 1 has an open reading frame capable of encoding a protein of 188 amino acid residues. To confirm the presence of the open reading frame, we constructed a recombinant vector (pMCP60) that contains a segment of the lambda cII translational initiation region, a portion of the N-terminus of the v-mos gene, and 639 base pairs of the first exon of the human c-myc gene. pMCP60 expresses a 38 kilodalton tripartate protein (cII-mos-myc), which was purified by high-pressure liquid chromatography. The presence of myc exon 1 sequences in the cII-mos-myc fusion protein was confirmed by partial amino acid sequence analysis. These experiments further establish that the first exon of the human c-myc gene contains an open reading frame capable of expressing a protein in Escherichia coli.