The chromokinesin Kid is required for maintenance of proper metaphase spindle size

The human chromokinesin Kid/kinesin-10, a plus end-directed microtubule (MT)-based motor with both microtubule- and DNA-binding domains, is required for proper chromosome alignment at the metaphase plate. Here, we performed RNA interference experiments to deplete endogenous Kid from HeLa cells and c...

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Bibliographic Details
Published inMolecular biology of the cell Vol. 16; no. 11; pp. 5455 - 5463
Main Authors Tokai-Nishizumi, Noriko, Ohsugi, Miho, Suzuki, Emiko, Yamamoto, Tadashi
Format Journal Article
LanguageEnglish
Published United States 01.11.2005
Subjects
Cell Nucleus - ultrastructure
DNA-Binding Proteins - genetics
DNA-Binding Proteins - physiology
HeLa Cells
Humans
In Vitro Techniques
Kinesin - genetics
Kinesin - physiology
Metaphase
Microtubules - metabolism
Models, Biological
RNA Interference
Spindle Apparatus - metabolism
Spindle Apparatus - ultrastructure
Transfection
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Summary:The human chromokinesin Kid/kinesin-10, a plus end-directed microtubule (MT)-based motor with both microtubule- and DNA-binding domains, is required for proper chromosome alignment at the metaphase plate. Here, we performed RNA interference experiments to deplete endogenous Kid from HeLa cells and confirmed defects in metaphase chromosome arm alignment in Kid-depleted cells. In addition, we noted a shortening of the spindle length, resulting in a pole-to-pole distance only 80% of wild type. The spindle microtubule-bundles with which Kid normally colocalize became less robust. Rescue of the two Kid deficiency phenotypes-imprecise chromosome alignment at metaphase and shortened spindles- exhibited distinct requirements. Mutants lacking either the DNA-binding domain or the MT motor ATPase failed to rescue the former defect, whereas rescue of the shortened spindle phenotype required neither activity. Kid also exhibits microtubule bundling activity in vitro, and rescue of the shortened spindle phenotype and the bundling activity displayed similar domain requirements, except that rescue required a coiled-coil domain not needed for bundling. These results suggest that distinct from its role in chromosome movement, Kid contributes to spindle morphogenesis by mediating spindle microtubules stabilization.
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ISSN:1059-1524
1939-4586
DOI:10.1091/mbc.e05-03-0244