Eukaryotic Translation Initiation Factor 3E (EIF3E)

By searching an EST database with the partial protein sequence of the rabbit eIF3-p48 subunit, Asano et al. (1997) identified cDNAs encoding human p48. The predicted human p48 protein contains 445 amino acids. Recombinant p48 coimmunoprecipitated with eIF3 and with the eIF3-p170 subunit. Northern blot analysis revealed that p48 is expressed as a 1.6-kb mRNA in HeLa cells. Asano et al. found that human p48 is identical to the mouse int6 gene product. The mouse int6 gene is a site where mouse mammary tumor virus (MMTV) frequently integrates, which may result in the expression of a truncated int6 protein. These authors also noted that int6 has been identified as a human protein that binds to the human T-cell leukemia virus type I Tax protein, leading to the translocation of int6 from the nucleus to the cytoplasm.