Kinetochore-dependent microtubule rescue ensures their efficient and sustained interactions in early mitosis.
Bottom Line: Meanwhile, microtubule rescue distal to the kinetochore is also promoted by Stu2, which is transported by a kinesin-8 motor Kip3 along the microtubule from the kinetochore.Microtubule extension following rescue facilitates interaction with other widely scattered kinetochores, diminishing long delays in collecting the complete set of kinetochores by microtubules.Thus, kinetochore-dependent microtubule rescue ensures efficient and sustained kinetochore-microtubule interactions in early mitosis.
Affiliation: Wellcome Trust Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.Show MeSH
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Mentions: Is MT rescue distal to the KT also dependent on Stu2, similar to rescue that occurs at the KT? Indeed, as we reported previously, MT rescue distal to CEN3 always happened coincidentally (24 out of 24 events) with arrival of Stu2 at the MT plus end after it had been transported from CEN3 along the MT lateral surface (Tanaka et al., 2005) (Figure 3Ai). Stu2 transport along a MT was not a misinterpretation of the Stu2 signal at the end of an overlapping, growing MT, which could be discerned by a partly thicker MT signal (Figure 3Aii, 75–165 s) and a prior Stu2 movement from a spindle pole to CEN3 (Figure 3Aii, 75–90 s). This conclusion was also confirmed by a separate experiment, using photobleaching of a MT region (Figure S2A). It appeared that Stu2 transport from a KT occurred and led to MT rescue distal to the KT not only in the engineered assay system (Figure 3Ai), but also in physiological conditions (Figure S2B). Stu2 transport from CEN3 along a MT was observed with similar frequency during MT growth and shrinkage in the engineered assay (data not shown). If Stu2 arrived at the end of a growing MT, there was no obvious effect.
Affiliation: Wellcome Trust Centre for Gene Regulation & Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.