000001567 001__ 1567 000001567 005__ 20240523045449.0 000001567 0247_ $$2doi$$a10.6082/uchicago.1567 000001567 041__ $$aen 000001567 245__ $$aTaxol-Stabilized Yeast Microtubules Reveal that a Subset of Spindle Checkpoint Proteins Delay Anaphase Onset in Response to Low Tension 000001567 260__ $$bThe University of Chicago 000001567 269__ $$a2017-12 000001567 300__ $$a158 000001567 336__ $$aDissertation 000001567 502__ $$bPh.D. 000001567 520__ $$aTo ensure genome stability during mitosis, the mitotic spindle must segregate sister chromosomes accurately. Multiple surveillance mechanisms, collectively referred to as the mitotic checkpoint, function to delay anaphase onset if sister chromosomes are not bound to microtubules from opposite spindle poles. Dominant signaling pathways within the mitotic checkpoint are the Spindle Assembly Checkpoint (SAC), which delays anaphase when kinetochores are not stably attached to microtubules, and the error correction mechanism, which induces detachment when microtubule-kinetochore attachments are not under tension. Together, these mechanisms promote stable, bipolar attachments in which dynamic microtubules can generate tension across sister kinetochores. However, the interdependency of kinetochore-microtubule attachment and tension has proved challenging to understanding whether this model fully explains how the mitotic checkpoint responds to the tension status at kinetochores. Unlike higher eukaryotes, budding yeast kinetochores bind only one microtubule, simplifying the relationship between attachment and tension. To address the role of tension in the mitotic checkpoint, we developed a Taxol-sensitive yeast model to reduce tension by stabilizing microtubules in fully assembled spindles. Our results show that reducing tension on bipolar, attached kinetochores delays anaphase onset. The tension-mediated delay is transient relative to the SAC delay imposed by unattached kinetochores. Furthermore, it requires the SAC proteins Bub1 and Bub3, but persists without Mad1, Mad2 and Mad3 (yeast BubR1). Together, our results demonstrate that reduced tension generates a ‘wait-anaphase’ signal during the mitotic checkpoint that is temporally and mechanistically distinct from that of unattached kinetochores. 000001567 542__ $$fUniversity of Chicago dissertations are covered by copyright. 000001567 650__ $$aMolecular biology 000001567 653__ $$abudding yeast 000001567 653__ $$akinetochore 000001567 653__ $$ametaphase 000001567 653__ $$amitosis 000001567 653__ $$aspindle assembly checkpoint 000001567 653__ $$atension 000001567 690__ $$aBiological Sciences Division 000001567 690__ $$aPritzker School of Medicine 000001567 691__ $$aCell and Molecular Biology 000001567 7001_ $$aProudfoot, Kathleen Grant$$uUniversity of Chicago 000001567 72012 $$aMohan Gupta 000001567 72012 $$aMichael Glotzer 000001567 72014 $$aDouglas Bishop 000001567 72014 $$aAllan Drummond 000001567 8564_ $$99a140625-ff6e-4a32-8bed-5fa4d29c47a8$$eEmbargo (2018-06-13)$$s18829437$$uhttps://knowledge.uchicago.edu/record/1567/files/Proudfoot_uchicago_0330D_14091.pdf 000001567 909CO $$ooai:uchicago.tind.io:1567$$pDissertations$$pGLOBAL_SET 000001567 983__ $$aDissertation