In this paper, we reported the identification of KKT4 as the first microtubule-binding kinetochore component in Trypanosoma brucei. We found that its microtubule-binding domain lacks similarity to any known microtubule-binding protein. In collaboration with Chip Asbury’s lab (University of Washington, Seattle, USA), we used single molecule assays (TIRF microscopy and optical tweezers) to reveal that KKT4 tracks dynamic microtubule tips even in the presence of external force. This means that KKT4 is capable of coupling chromosomes to dynamic microtubule ends. Our next goal is to obtain structural information of how KKT4 interacts with microtubules as well as to understand its regulation.
The kinetoplastid kinetochore protein KKT4 is an unconventional microtubule tip–coupling protein.
Aida Llauró, Hanako Hayashi, Megan E. Bailey, Alex Wilson, Patryk Ludzia, Charles L. Asbury, Bungo Akiyoshi