Besides, its middle domains contain two heterodimers of Ndc80-NUF2 Spc24-Spc25pc25, whave have been suggested to be necessary in formation of stable microtubule kinetochore attachment, chromosome alignment, and spindle checkpoint activation in mitosis [ 10].
The easiest to appreciate is the "spindle checkpoint".
hSPC105 is required for correct mitotic timing and spindle checkpoint activity.
As control strains, wild-type (checkpoint proficient) and checkpoint mutants for DNA damage/DNA replication mec1 sml1 and spindle checkpoint mutant bub1 were used.
We propose that this N-terminal KEN box, which is conserved from yeast Mad3p to human BubR1, is a critical link required for MCC formation and spindle checkpoint inhibition of Cdc20p.
In addition to their roles in cell cycle arrest, some spindle checkpoint components also actively promote the formation of correct microtubule-chromosome attachments (4).
These data suggest that MK2 most likely contributes to meiotic bipolar spindle assembly, similar to mitosis where MK2 functions in bipolar spindle formation shown by MK2 depletion which induced mitotic defects in bipolar spindle formation and subsequent activation of the spindle checkpoint [47].
Mad1p Bub1p Bub3p complex formation is essential for proper spindle checkpoint function in yeast (Brady and Hardwick 2000).
This interaction causes abnormal spindle formation and activation of the spindle checkpoint, which leads to metaphase arrest, inhibition of further cell proliferation and the induction of cell death [ 6, 10, 11, 19].
Several antimitotic drugs including the taxanes and the vinca alkaloids, via their effects on microtubules, prevent the formation of a normal mitotic spindle, resulting in spindle checkpoint activation.
Brady, D. M. & Hardwick, K. G. Complex formation between Mad1p, Bub1p and Bub3p is crucial for spindle checkpoint function.
