Spindle-kinetochore attachment requires the combined action of Kin I-like Klp5/6 and Alp14/Dis1-MAPs in fission yeast.
Fission yeast Klp5 and Klp6 belong to the microtubule-destabilizing Kin I family. In klp5 mutants, spindle checkpoint proteins Mad2 and Bub1 are recruited to mitotic kinetochores for a prolonged duration, indicating that these kinetochores are unattached. Further analysis shows that there are kinetochores to which only Bub1, but not Mad2, localizes. These kinetochores are likely to have been captured, yet lack tension. Thus Klp5 and Klp6 play a role in a spindle- kinetochore interaction at dual steps, capture and generation of tension. The TOG/XMAP215 family, Alp14 and Dis1 are known to stabilize microtubules and be required for the bivalent attachment of the kinetochore to the spindle. Despite apparent opposing activities towards microtubule stability, Klp5/Klp6 and Alp14/Dis1 share an essential function, as either dis1klp or alp14klp mutants are synthetically lethal, like alp14dis1. Defective phenotypes are similar to each other, characteristic of attachment defects and chromosome mis-segregation. Furthermore Alp14 is of significance for kinetochore localization of Klp5. We propose that Klp5/Klp6 and Alp14/Dis1 play a collaborative role in bipolar spindle formation during prometaphase through producing spindle dynamism.
Garcia
Miguel Angel
MA
Laboratory of Cell Regulation, Cancer Research UK, London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
Koonrugsa
Nirada
N
Toda
Takashi
T
D015825:Chromosomes, Fungal / Q000502:physiology*; D016547:Kinesins / Q000235:genetics / Q000502:physiology*; D018386:Kinetochores / Q000502:physiology* / Q000648:ultrastructure; D046911:Macromolecular Substances; D008677:Metaphase; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000502:physiology*; D008870:Microtubules / Q000737:chemistry / Q000648:ultrastructure; D010641:Phenotype; D025941:Protein Interaction Mapping; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000502:physiology*; D008941:Spindle Apparatus / Q000502:physiology*
D046911:Macromolecular Substances; D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins; C432090:alp14 protein, S pombe; C094879:dis1 protein, S pombe; C469734:Klp5 protein, S pombe; C459102:Klp6 protein, S pombe; D016547:Kinesins