Characterization of a gene coamplified with Ki-ras in Y1 murine adrenal carcinoma cells that codes for a putative membrane protein.

We report the sequence and genomic organization of a gene linked to Ki-ras in the mouse and coamplified in Y1 murine adrenal carcinoma cells. The entire 4.4-kb cDNA sequence as well as promoter and splice sites for each of the three exons was determined. The gene, designated KRAG (Ki-ras-associated gene) has a CG-rich first exon and promoter region and a long 3' untranslated region and encodes 216 amino acids. The putative 23.9-kDa protein has four potential transmembrane hydrophobic domains. The hydropathy plot resembles that of certain tumor-associated antigens, including CO-029 and ME491. A potential human homologue, EST05985, was identified and provisionally mapped to human chromosome 12, a chromosome syntenic to mouse chromosome 6, the previously mapped location of KRAG.