The MEN mediates the effects of the spindle assembly checkpoint on Kar9-dependent spindle pole body inheritance in budding yeast

 Abstract

Many asymmetrically dividing cells segregate the poles of the mitotic spindle non-randomly between their two daughters. In budding yeast, the protein Kar9 localizes almost exclusively to the astral microtubules emanating from the old spindle pole body (SPB) and promotes its movement toward the bud. Thereby, Kar9 orients the spindle relative to the division axis. Here, we show that beyond perturbing Kar9 distribution, activation of the spindle assembly checkpoint (SAC) randomizes SPB inheritance. Inactivation of the B-type cyclin Clb5 led to a SAC-dependent defect in Kar9 orientation and SPB segregation. Furthermore, unlike the Clb4-dependent pathway, the Clb5- and SAC-dependent pathways functioned genetically upstream of the mitotic exit network (MEN) in SPB specification and Kar9-dependent SPB inheritance. Together, our study indicates that Clb5 functions in spindle assembly and that the SAC controls the specification and inheritance of yeast SPBs through inhibition of the MEN.

Full Text Options
Article
Metrics
 Share
 Full Text
 Supplemental Material
 Info
Pages
3109 - 3116
doi
10.4161/cc.21504
Type
Report
 Metrics
 Cite This Article
 Permissions
 Permissions
 Reprints
The MEN mediates the effects of the spindle assembly checkpoint on Kar9-dependent spindle pole body inheritance in budding yeast