Sequence, topography and protein coding potential of mouse int-2: a putative oncogene activated by mouse mammary tumour virus.

Abstract

A major proportion of carcinomas induced by mouse mammary tumour virus (MMTV) show evidence for proviral activation of a cellular gene, int‐2, on chromosome 7. The sequence of 7869 bp of DNA spanning the transcription unit of int‐2 was determined and compared with that of a series of int‐2‐specific cDNA clones derived from mammary tumour RNA. The predicted positions of intron‐exon boundaries, established by alignment of cDNA and chromosomal DNA sequences, indicate that the gene comprises at least three exons. An open reading frame capable of encoding a protein of 245 amino acids with an estimated mol. wt of 27 kd, is flanked by substantial non‐coding segments at both 5′ and 3′ ends. Comparison of the chromosomal DNA sequence and the predicted amino acid sequence with available data‐bases has revealed no homology to other known genes. These results are discussed in relation to the status of int‐2 as a candidate proto‐oncogene.