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Citation
Althoff, F., Karess, R.E., Lehner, C.F. (2012). Spindle checkpoint-independent inhibition of mitotic chromosome segregation by Drosophila Mps1.  Mol. Biol. Cell 23(12): 2275--2291.
FlyBase ID
FBrf0218626
Publication Type
Research paper
Abstract

Monopolar spindle 1 (Mps1) is essential for the spindle assembly checkpoint (SAC), which prevents anaphase onset in the presence of misaligned chromosomes. Moreover, Mps1 kinase contributes in a SAC-independent manner to the correction of erroneous initial attachments of chromosomes to the spindle. Our characterization of the Drosophila homologue reveals yet another SAC-independent role. As in yeast, modest overexpression of Drosophila Mps1 is sufficient to delay progression through mitosis during metaphase, even though chromosome congression and metaphase alignment do not appear to be affected. This delay in metaphase depends on the SAC component Mad2. Although Mps1 overexpression in mad2 mutants no longer causes a metaphase delay, it perturbs anaphase. Sister kinetochores barely move apart toward spindle poles. However, kinetochore movements can be restored experimentally by separase-independent resolution of sister chromatid cohesion. We propose therefore that Mps1 inhibits sister chromatid separation in a SAC-independent manner. Moreover, we report unexpected results concerning the requirement of Mps1 dimerization and kinase activity for its kinetochore localization in Drosophila. These findings further expand Mps1's significance for faithful mitotic chromosome segregation and emphasize the importance of its careful regulation.

PubMed ID
PubMed Central ID
PMC3374747 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Mol. Biol. Cell
    Title
    Molecular Biology of the Cell
    Publication Year
    1992-
    ISBN/ISSN
    1059-1524
    Data From Reference
    Aberrations (1)
    Alleles (45)
    Genes (14)
    Physical Interactions (5)
    Cell Lines (1)
    Natural transposons (1)
    Insertions (2)
    Experimental Tools (6)
    Transgenic Constructs (37)