Characterisation of agrobacterium VirD2 interacting protein DIP and its homologues

Abstract

When A. tumefaciens VirD2-interacting protein, DIP, was transiently a??knocked downa?? by RNA interference (RNAi) in plant cells and tissues, these cells and tissues became less receptive to transformation by A. tumefaciens. The transgenic a??knock downa?? cell lines grew slower and were less efficiently transformed by A. tumefaciens. Moreover, homozygous Arabidopsis DIP -/- a??knock outa?? mutants could not be generated. These demonstrate that DIP plays a crucial role in the basic biological process(es) and it is important for Agrobacterium-mediated transformation of plant cells. In addition, the nuclear localization sequences of VirD2 were found to be not required for its interaction with DIP. Subsequent study of the human homologue of DIP, hDIP, which is part of a highly conserved exocyst complex, indicated that antibody against hDIP could not be raised in either rabbits or mice. These imply that the exocyst complex might be manipulated by A. tumefaciens to transform its host cell.