A novel pathway that coordinates mitotic exit with spindle position.
In budding yeast, the spindle position checkpoint (SPC) delays mitotic exit until the mitotic spindle moves into the neck between the mother and bud. This checkpoint works by inhibiting the mitotic exit network (MEN), a signaling cascade initiated and controlled by Tem1, a small GTPase. Tem1 is regulated by a putative guanine exchange factor, Lte1, but the function and regulation of Lte1 remains poorly understood. Here, we identify novel components of the checkpoint that operate upstream of Lte1. We present genetic evidence in agreement with existing biochemical evidence for the molecular mechanism of a pathway that links microtubule-cortex interactions with Lte1 and mitotic exit. Each component of this pathway is required for the spindle position checkpoint to delay mitotic exit until the spindle is positioned correctly.
Nelson
Scott A
SA
Department of Cell Biology, Washington University in St. Louis, St. Louis, MO 63110, USA.
Cooper
John A
JA
D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism*; D013489:Suppression, Genetic
D020662:Guanine Nucleotide Exchange Factors; C089357:LTE1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins