CENP-meta, an essential kinetochore kinesin required for the maintenance of metaphase chromosome alignment in Drosophila

CENP-meta has been identified as an essential, kinesin-like motor protein i n Drosophila. The 257-kD CENP-meta protein is most similar to the vertebrat e kinetochore-associated kinesin-like protein CENP-E, and like CENP-E, is s hown to be a component of centromeric/kinetochore regions of Drosophila chr omosomes. However, unlike CENP-E, which leaves the centromere/kinetochore r egion at the end of anaphase A, the CENP-meta protein remains associated wi th the centromeric/kinetochore region of the chromosome during all stages o f the Drosophila cell cycle. P-element-mediated disruption of the CENP-meta gene leads to late larval/pupal stage lethality with incomplete chromosome alignment at metaphase. Complete removal of CENP-meta from the female germ line leads to lethality in early embryos resulting from defects in metaphas e chromosome alignment. Real-time imaging of these mutants with GFP-labeled chromosomes demonstrates that CENP-meta is required for the maintenance of chromosomes at the metaphase plate, demonstrating that the functions requi red to establish and maintain chromosome congression have distinguishable r equirements.