Screening of protein interacting with apoptin by yeast two-hybrid from human leucocyte cDNA library

Using yeast two-hybrid system to screen the protein interacting with apoptin from human leucocyte cDNA library, four clones interacting with apoptin were identified. One of them was homologue with ABP280 (actin-binding protein), ABP280 is a dimeric actin crossing protein and plays a key role in stabilizing the membrane-cytoskeleton. Cell co-immunoprecipitation showed that apoptin could bind to ABP280 in mammalian cells. Apoptin mutants T1, T2 and T3 lack the C-terminal 11 amino acid, 33-46 amino acid and both respectively. Apoptin mutants T2 and T3 failed to interact with ABP280, which revealed that its 33-46 amino acid was pivotal for the interaction. Apoptin mutant T1 still interacted with ABP280, which revealed that its C-terminal 11 amino acid was not essential for the interaction.