In @entity375 , the spindle position checkpoint ensures that cells do not exit mitosis until the mitotic spindle moves into the mother/bud neck and thus guarantees that each cell receives one nucleus [1-6]. Mitotic exit is controlled by the small G protein @entity42526 . @entity42526 and its GTPase activating protein (GAP) @entity45548 / @entity16256 are located on the daughter-bound spindle pole body. The GEF @entity42527 is located in the bud. This segregation helps keep @entity42526 in its inactive @entity3006 state until the spindle enters the neck. However, the checkpoint functions without @entity42527 and apparently senses cytoplasmic microtubules in the mother/bud neck [7-9]. To investigate this mechanism, we examined mutants defective for septins, which compose a ring at the neck [10]. We found that the septin mutants sep7Delta and @entity43080 Delta are defective in the checkpoint. When movement of the spindle into the neck was delayed, mitotic exit occurred, inappropriately leaving both nuclei in the mother. In sep7Delta and cdc10Delta mutants, @entity42527 is mislocalized to the mother. In sep7Delta, but not cdc10Delta, mutants, inappropriate mitotic exit depends on @entity42527 . These results suggest that septins serve as a diffusion barrier for @entity42527 , and that @entity43080 is needed for the septin ring to serve as a scaffold for a putative microtubule sensor.

Septins have a dual role in controlling mitotic exit in budding XXXX .

@entity43080 :: ('850358(Tax:4932)', 'Gene') :: ['cdc10', 'Cdc10p'] @entity16256 :: ('853513(Tax:4932)', 'Gene') :: ['Bfa1p'] @entity42526 :: ('854938(Tax:4932)', 'Gene') :: ['Tem1p'] @entity3006 :: ('MESH:D006153', 'Chemical') :: ['GDP'] @entity45548 :: ('855077(Tax:4932)', 'Gene') :: ['Bub2p'] @entity42527 :: ('851209(Tax:4932)', 'Gene') :: ['Lte1p'] @entity375 :: ('4932', 'Species') :: ['Saccharomyces cerevisiae']
@entity375 :: (4932,Species) :: ['yeast']
