Searching for Drosophila Dsn1 kinetochore protein.

The Mis12/MIND kinetochore complex is composed of 4 subunits of which the Dsn1 protein is a crucial component in all organisms where it has been identified. In Caenorhabditis elegans, depletion of Dsn1 results in a so-called "kinetochore null" phenotype, hence Dsn1's alternative name KNL3. In human, Dsn1 is required to shape an interface between the Mis12 complex and Blinkin, the counterpart of Spc105. In Drosophila however, despite many efforts using sequence comparisons and proteomics-based studies, a Dsn1 ortholog has not been found. Here we speculate that Drosophila Spc105R, a protein very much diverged from its counterparts in other species, might not only be playing the role of Spc105 itself but also of Dsn1.