Pleiotropic effects of HTLV type 1 Tax protein on cellular metabolism: Mitotic checkpoint abrogation and NF-κB activation

Tax protein expressed by human T cell leukemia virus type 1 (HTLV-1) is a strong trans-activator of its own LTR promoter; it also affects the function of multiple cellular genes involved in cell cycle control and transcription. One way in which Tax exerts its pleiotropic effects is through protein-protein interaction with cellular cofactors. By using yeast two-hybrid technology, we have isolated several cellular proteins that bind to Tax. Two of these are MAD1, a mitotic checkpoint control protein, and TXBP151, a suppressor of tumor necrosis factor α-induced apoptosis. Here we discuss findings describing the role of MAD1 in exit of cells from mitosis and TXBP151 in NF-κB activation.