We have constructed retroviral expression vectors by manipulation of the Moloney murine leukemia virus genome such that an exogenous DNA sequence may be inserted and subsequently expressed when introduced into mammalian cells. A series of N-terminal deletions of the v-mos oncogene was constructed and asssayed for biological activity with these retroviral expression vectors. The results of the deletion analysis demonstrate that the region of p37(mos) coding region upstream of the third methionine codon is dispensable with respect to transformation. However, deletion mutants of v-mos which allow initiation of translation at the fourth methionine codon have lost the biological activity of the parental v-mos gene. Furthermore, experiments were also carried out to define the C-terminal limit of the active region of p37(mos) by the construction of premature termination mutants by the insertion of a termination oligonucleotide. Insertion of the oligonucleotide just 69 base pairs upstream from the wild-type termination site abolished the focus-forming ability of v-mos. Thus, we have shown the N-terminal limit of the active region of p37(mos) to be between the third and fourth methionines, while the C-terminal limit is within the last 23 amino acids of the protein.
|Original language||English (US)|
|Number of pages||8|
|Journal||Molecular and Cellular Biology|
|State||Published - 1985|
ASJC Scopus subject areas
- Cell Biology
- Molecular Biology