Spatiotemporal control of spindle midzone formation by PRC1 in human cells
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Edited by Tony Hunter, The Salk Institute for Biological Studies, La Jolla, CA, and approved March 1, 2006 (received for review August 10, 2005)
Abstract
We have examined the role of PRC1, a midzone-associated, microtubule bundling, Cdk substrate protein, in regulating the spatiotemporal formation of the midzone in HeLa cells. Cdk-mediated phosphorylation of PRC1 in early mitosis holds PRC1 in an inactive monomeric state. During the metaphase-to-anaphase transition, PRC1 is dephosphorylated, promoting PRC1 oligomerization. Using time-lapse video microscopy, RNA interference, 3D immunofluorescence reconstruction imaging, and rescue experiments, we demonstrate that the dephosphorylated form of PRC1 is essential for bundling antiparallel, nonkinetochore, interdigitating microtubules to establish the midzone that is necessary for cytokinesis. Our results thus indicate that PRC1 is an essential factor in controlling the spatiotemporal formation of the midzone in human cells.
Footnotes
- †To whom correspondence should be addressed. E-mail: wjiang{at}burnham.org
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Author contributions: C.Z. and W.J. designed research; C.Z. and E.L. performed research; R.S. and E.B.-W. contributed new reagents/analytic tools; C.Z. and W.J. analyzed data; and C.Z. and W.J. wrote the paper.
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Conflict of interest statement: No conflicts declared.
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This paper was submitted directly (Track II) to the PNAS office.
- Abbreviations:
- ECFP,
- enhanced cyan fluorescent protein;
- EYFP,
- enhanced yellow fluorescent protein;
- MT,
- microtubule;
- siRNA,
- small interfering RNA
Abbreviations:
- © 2006 by The National Academy of Sciences of the USA
