Association of v-Mos with soluble vimentin in vitro and in transformed cells

Our previous studies have shown that vimentin can serve as a substrate for the v-Mos protein kinase in vitro. Furthermore, the amount of vimentin molecules in Moloney murine sarcoma virus (Mo-MuSV) transformed cells is decreased relative to uninfected cells and a lower molecular weight form is observed in these v-mos transformed cells (Singh & Arlinghaus, Virology 173: 144-156, 1989). Vimentin filaments are hyperphosphorylated and disassemble when cells enter mitosis. Here, we show that vimentin was coprecipitated with p85gag-mos from mitotic cell extracts by two different anti-Mos antibodies that do not crossreact with vimentin. However, we were unable to detect vimentin/v-Mos complexes interphase extracts, possibly due to lack of soluble vimentin. p37env-mos was also found to associate with purified bovine lens vimentin in vitro. The significance of these findings with regard to v-mos-induced cellular transformation is discussed.