XB-IMG-122922
Xenbase Image ID: 122922
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Figure 5. A model for CENP-E as a motile, flexible tether for kinetochore microtubule capture and maintenance of linkage to dynamic spindle microtubules. (A) Using its slow processive motor activity and a weak diffusive binding mode to microtubules, CENP-E walks toward the plus ends of kinetochore microtubules or diffuses along the lattice without dissociating for extended periods. (B) The 230-nm-long coiled coil of CENP-E functions as a safety catch for disassembling microtubules detached from the core kinetochore attachment components, thereby stabilizing the microtubule and enabling rescue. (C) CENP-E is likely to be a part of the kinetochore slip clutch that is engaged on fluxing kinetochore microtubules with its slow plus end–directed motility (Maddox et al., 2003a). CENP-E bound to the microtubule surface may affect kinetochore microtubule plus ends, thereby promoting growth and allowing recapture. (D) Unlike other shorter and more rigidly structured kinetochore capture components, multiple CENP-E molecules are likely to work together by allowing the simultaneous attachment at many different microtubule orientations relative to the kinetochore axis without forcing each other into unproductive conformations. (E) The highly flexible extended coiled coil of CENP-E mediates the initial capture of microtubules by searching a large volume in cells. (F) Its slow, processive motility powers monooriented chromosomes to congress using an adjacent kinetochore fiber (Kapoor et al., 2006). Image published in: Kim Y et al. (2008) © 2008 Kim et al. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike license Larger Image Printer Friendly View |