Authors

Discussion

Kinetochores assemble at centromeric DNA to interact with spindle microtubules. In many eukaryotes, a centromeric histone H3 variant CENP-A epigenetically specifies kinetochore assembly sites within centromeres. However, Trypanosoma brucei lacks CENP-A and conventional kinetochore proteins, instead relying on a unique set of proteins (KKTs). KKT2 and KKT3 form the base of trypanosome kinetochores and recruit other KKTs to assemble kinetochores. However, it remains unknown how they specifically localise at centromeres. Here, we show that the centromere localization (CL) domain of KKT2 interacts with the unmodified N-terminus of histone H3 in vitro. Using custom monoclonal antibody, we also show that the histone H3 N-terminus is unmodified specifically at centromeres in a subset of G1 cells. These results suggest that the N-terminus of histone H3 is unmodified at centromeres, which helps to determine kinetochores assembly sites in trypanosomes.