Identification of a protein interacting with apoptin from human leucocyte cDNA library by using yeast two-hybrid screening

To screen the protein interacting with apoptin from human leucocyte cDNA library by using yeast two-hybrid system, four clones interacting with apoptin were identified. One of them was homologous with Nmi (N-Myc interaction protein). Cell co-immunoprecipitation showed that apoptin could bind to Nmi in mammalian cells. Apoptin mutants T1, T2 and T3 lacked the C-terminal 11 AA, 33-46 AA and both, respectively. Apoptin mutants T2 and T3 failed to interact with Nmi, suggesting that its 33-46 AA was pivotal for the interaction. Apoptin mutant T1 still interacted with Nmi, suggesting that its C-terminal 11 AA was not essential for the interaction.