We discovered a conserved kinase, Bub1p, that acts at an early step in the generation of the signal indicating spindle damage. Recently, another lab has linked mutant forms of human BUB1 to the transformed growth properties of cancerous human cells. Proposed roles for four mitotic spindle motor proteins. Prior to the onset of anaphase, Cin8p an Kip1p are opposed by the actions of kinesin-related Kar3p, although the mechanism of this motor is not clear. Dynein is proposed to contribute to pole separation from outside the poles at the cell cortex.
Arrows indicate motor movement relative to microtubule substrate.
S. cerevisiae Genes Required for Cell Cycle Arrest in Response to Loss of Microtubule Function. J. Cell Biol. Kinesin-related Proteins Required for Structural Integrity of the Mitotic Spindle. The Saccharomyces cerevisiae Checkpoint Gene BUB1 Encodes a Novel Protein Kinase. Dynein-related Proteins Required for Anaphase Chromosome Segregation J. Cell Biol.