The spindle position checkpoint is coordinated by the Elm1 kinase

How dividing cells monitor the effective transmission of genomes during mitosis is poorly understood Budding yeast use a signaling pathway known as the spindle position checkpoint (SPC) to ensure the arrival of one end of the mitotic spindle in the nascent daughter cell An important question is how SPC activity is coordinated with mother-daughter polarity We sought to identify factors at the bud neck, the junction between mother and bud, which contribute to checkpoint signaling In this paper, we show that the protein kinase Elm1 is an obligate regulator of the SPC, and this function re quires localization of Elm1 to the bud neck Furthermore, we show that Elm1 promotes the activity of the checkpoint kinase Kin4 These findings reveal a novel function for Elm1 in the SPC and suggest how checkpoint activity may be linked to cellular organization