A BAR homology domain containing protein, EhABP is the novel interactor of EhAK7, an aurora kinase homolog in E. histolytica

Biomolecular interactions among proteins are fundamental for all cellular functions. The chromosome segregation proteins are the key regulators of inherent functions in the living cells. Aurora kinases have drawn much interest as possible drug targets in higher eukaryotes. The human pathogen, E. histolytica is the causative agent of amoebiasis, and a major health concern in developing countries. However, there is no vaccine against it and the popular drugs- metronidazole, tinidazole etc. show significant side effects in humans. To identify new controlling agents, we must have a thorough knowledge about the cell cycle regulatory proteins of E. histolytica, as many unusual cell cycle events can be found in this parasite, that do not happen in human cells. This study describes the first comprehensive analysis of the interaction between an aurora kinase protein and a BAR homology domain containing protein. Fes/CIP4 and EFC/F-BAR homology domain (FCH) containing protein, EhABP has been identified as a novel interactor of EhAK7, an aurora kinase homolog from E. histolytica by yeast two-hybrid screening against the cDNA library of E. histolytica and their interaction has been proved by in vitro binding assay. Both the N and C-terminus of EhAK7 are responsible for this interaction. We found the reduced expression of EhAK7 and EhABP genes, defects in actin filament organization and irregular-shaped nucleus in the trophozoites treated with an aurora kinase inhibitor VX-680. This indicates that EhAK7 play an important role in the cytokinesis of E. histolytica through the interaction with a BAR homology domain containing protein, EhABP.