Survivin is a component of the Chromosomal Passenger Complex (CPC) that plays a
role in maintenance of an active spindle checkpoint and in cytokinesis. To study if
these different functions can be attributed to distinct domains within the Survivin
protein, we complemented Survivin-depleted cells with a variety of point- and
deletion-mutants of Survivin. We show that an intact BIR domain is required for
proper spindle checkpoint functioning, but dispensable for cytokinesis. In line with
this, mutants lacking an intact BIR domain localized normally to the central spindle,
but their localization to inner centromeres was severely perturbed. Consequently,
these mutants failed to recruit Aurora B, Borealin/Dasra B and BubR1 to centromeres
and kinetochores, but had retained the ability to recruit Aurora B and Borealin/Dasra
B to the midzone and midbody. Thus the C-terminus of Survivin is sufficient for
central spindle localization and execution of cytokinesis, but the additional presence
of a functional BIR domain is essential for centromere targeting and spindle
checkpoint function. Importantly, our data show that the function of the CPC at the
centromere can be separated from its function at the central spindle, and that
execution of cytokinesis does not require prior concentration of the CPC at
centromeres.
Is data on this page outdated, violates copyrights or anything else? Report the problem now and we will take corresponding actions after reviewing your request.