Michael Glotzer

..Cytokinesis involves additional proteins, but they, or their requirement in cytokinesis, are not conserved among animal cells...

..Although the mechanism of cleavage furrow positioning is not understood at a molecular level, recent results suggest that it might be mediated by local relief from the inhibitory effects of microtubules...

..Thus, central spindle localization of ECT2 assists division plane positioning and the CYK-4 subunit of centralspindlin acts upstream of RhoA to promote furrow assembly...

..Thus, phosphoregulation of the motor domain of MKLP1 kinesin ensures that central spindle assembly occurs at the appropriate time in the cell cycle and maintains genomic stability...

..We propose that late mitotic Plk1 activity promotes recruitment of Ect2 to the central spindle, triggering the initiation of cytokinesis and contributing to cleavage plane specification in human cells...

..Inhibition of aurora B in late anaphase causes cytokinesis defects without disrupting the central spindle. These data indicate a conserved role for aurora-B-mediated phosphorylation of ZEN-4/MKLP1 in the completion of cytokinesis...

..New results have provided some initial clues as to how furrow positioning is achieved. Particularly notable is the discovery that a protein activated by RhoA, formin, has actin nucleation activity...

..Scc1 interacts with SMC proteins through N- and C-terminal domains to form a ring-like structure. Since these are the only domains conserved among kleisins, we suggest that ring formation with SMC proteins may define this family...

..ICP-1 dramatically stimulates AIR-2 kinase activity. This activity is not stimulated by CSC-1/BIR-1, suggesting that these two subunits function as targeting subunits for AIR-2 kinase...

..Important transitions in the cell cycle are regulated by ubiquitin-dependent degradation of specific proteins. Recent data indicate that cytokinesis is also regulated by proteolysis...

..Aurora B kinase is known to regulate localization of centralspindlin and may regulate the activity of the RhoGAP component of centralspindlin...

..The mechanisms responsible for orienting kinetochores in mitosis and for causing asynchronous loss of cohesion during meiosis are not well understood...

..Biochemical studies indicate that this complex, named centralspindlin, is a heterotetramer. Centralspindlin, but not its individual components, strongly promotes microtubule bundling in vitro...

..If the properties of Xl Sept2 filaments reflect those of native septin complexes, these results imply that the growth or stability of septin filaments, or both, is regulated by the state of bound nucleotide...

..These data suggest that reduced microtubule density triggers cleavage furrow initiation and demonstrate that redundant mechanisms direct efficient formation of the cleavage furrow...

..We review our current understanding of the molecular mechanisms of furrow formation, with particular emphasis on the central spindle-independent pathway...

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..This unexpected plasticity explains the lack of primary sequence conservation of the regions critical for this essential protein-protein interaction...

..In both C. elegans embryos and human cells, the central spindle regulates division-plane positioning in parallel with a second pathway that involves astral microtubules...

..These data indicate that the deubiquitination of certain substrates by CYK-3 is crucial for cellular osmoregulation. Defects in osmoregulation appear to indirectly affect actin-dependent processes...

..Furthermore, we investigated the location, structure, and function of a highly conserved extension of approximately 50 residues unique to the Kinesin-6 subfamily, located in the motor core loop6/beta4 region...

..Advances in detecting the active pool of RhoA have allowed insights into the mechanisms and the molecules that promote the accumulation of active RhoA at the correct time and place in the cell...

..These findings identify the CDC14 phosphatase as an important regulator of central spindle formation and cytokinesis in a metazoan organism...

..To evaluate the overall evolutionary conservation of cytokinesis, it will be necessary to include representatives of these divergent branches. Nevertheless, the three species discussed here provide substantial mechanistic diversity...

..Thus, we propose that centralspindlin complex not only regulates acto-myosin ring contraction but also endocytic vesicle transport to the cleavage furrow and it does so through sequential interactions with ECT2 and FIP3...

..The human and mouse septin genes will be named SEPT1-SEPT10 and Sept1-Sept10, respectively. Splice variants will be designated by an underscore followed by a lowercase "v" and a number, e.g., SEPT4_v1...

..These data suggest that PRC1 is a dose-dependent regulator of the central spindle in vertebrate embryos and demonstrate unexpected plasticity to fundamental mechanisms of cell division...