Centromere targeting of alien CENH3s in Arabidopsis and tobacco cells.

The centromere is a region utilized for spindle attachment on a eukaryotic chromosome and essential for accurate chromatid segregation. In most eukaryotes, centromeres have specific DNA sequences and are capable of assembling specific proteins to form a complex called the kinetochore. Among these proteins, centromeric histone H3 (CENH3) is one of the most fundamental, since CENH3s have been found in all investigated functional centromeres and recruits other centromeric proteins. In this study, the localization of alien CENH3s were analyzed in Arabidopsis and tobacco-cultured cells to determine the interaction between species-specific centromeric DNA and CENH3. Results showed that CENH3 of Arabidopsis and tobacco were localized on centromeres in the tobacco-cultured cells, unlike the case with CENH3 of rice and Luzula. In addition to these CENH3s, CENH3 of Luzula was partially localized in the Arabidopsis cultured cells. These data suggest that only evolutionally close CENH3s are able to target centromeres in alien species. Furthermore, the ability to target alien centromeres of histone fold domains was investigated using amino-terminal deleted CENH3s.