BINDING OF MURINE LEUKEMIA-VIRUS GAG POLYPROTEINS TO KIF4, A MICROTUBULE-BASED MOTOR PROTEIN

A cDNA clone encoding a cellular protein that interacts with murine le ukemia virus (MuLV) Gag proteins was isolated from a T-cell lymphoma l ibrary. The sequence of the clone is identical to the C terminus of a cellular protein, KIF4, a microtubule-assoclated motor protein that be longs to the kinesin superfamily. KTF4-MuLV Gag associations have been detected in vitro and in vivo in mammalian cells. We suggest that KIF 4 could be involved in Gag polyprotein translocation from the cytoplas m to the cell membrane.