scholarly journals Contractile Ring-independent Localization of DdINCENP, a Protein Important for Spindle Stability and Cytokinesis

2006 ◽  
Vol 17 (2) ◽  
pp. 779-788 ◽  
Author(s):  
Qian Chen ◽  
Hui Li ◽  
Arturo De Lozanne

Dictyostelium DdINCENP is a chromosomal passenger protein associated with centromeres, the spindle midzone, and poles during mitosis and the cleavage furrow during cytokinesis. Disruption of the single DdINCENP gene revealed important roles for this protein in mitosis and cytokinesis. DdINCENP null cells lack a robust spindle midzone and are hypersensitive to microtubule-depolymerizing drugs, suggesting that their spindles may not be stable. Furthermore DdCP224, a protein homologous to the microtubule-stabilizing protein TOGp/XMAP215, was absent from the spindle midzone of DdINCENP null cells. Overexpression of DdCP224 rescued the weak spindle midzone defect of DdINCENP null cells. Although not required for the localization of the myosin II contractile ring and subsequent formation of a cleavage furrow, DdINCENP is important for the abscission of daughter cells at the end of cytokinesis. Finally, we show that the localization of DdINCENP at the cleavage furrow is modulated by myosin II but it occurs by a mechanism different from that controlling the formation of the contractile ring.

Biology ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 55 ◽  
Author(s):  
Vikash Verma ◽  
Alex Mogilner ◽  
Thomas J. Maresca

The primary goal of cytokinesis is to produce two daughter cells, each having a full set of chromosomes. To achieve this, cells assemble a dynamic structure between segregated sister chromatids called the contractile ring, which is made up of filamentous actin, myosin-II, and other regulatory proteins. Constriction of the actomyosin ring generates a cleavage furrow that divides the cytoplasm to produce two daughter cells. Decades of research have identified key regulators and underlying molecular mechanisms; however, many fundamental questions remain unanswered and are still being actively investigated. This review summarizes the key findings, computational modeling, and recent advances in understanding of the molecular mechanisms that control the formation of the cleavage furrow and cytokinesis.


2000 ◽  
Vol 149 (6) ◽  
pp. 1215-1224 ◽  
Author(s):  
Kazuo Emoto ◽  
Masato Umeda

Phosphatidylethanolamine (PE) is a major membrane phospholipid that is mainly localized in the inner leaflet of the plasma membrane. We previously demonstrated that PE was exposed on the cell surface of the cleavage furrow during cytokinesis. Immobilization of cell surface PE by a PE-binding peptide inhibited disassembly of the contractile ring components, including myosin II and radixin, resulting in formation of a long cytoplasmic bridge between the daughter cells. This blockade of contractile ring disassembly was reversed by removal of the surface-bound peptide, suggesting that the PE exposure plays a crucial role in cytokinesis. To further examine the role of PE in cytokinesis, we established a mutant cell line with a specific decrease in the cellular PE level. On the culture condition in which the cell surface PE level was significantly reduced, the mutant ceased cell growth in cytokinesis, and the contractile ring remained in the cleavage furrow. Addition of PE or ethanolamine, a precursor of PE synthesis, restored the cell surface PE on the cleavage furrow and normal cytokinesis. These findings provide the first evidence that PE is required for completion of cytokinesis in mammalian cells, and suggest that redistribution of PE on the cleavage furrow may contribute to regulation of contractile ring disassembly.


2005 ◽  
Vol 83 (6) ◽  
pp. 696-702 ◽  
Author(s):  
David Bouck ◽  
Kerry Bloom

The spindle midzone is critical for spindle stability and cytokinesis. Chromosomal passenger proteins relocalize from chromosomes to the spindle midzone after anaphase onset. The recent localization of the inner-kinetochore, centromere-binding factor 3 (CBF3) complex to the spindle midzone in budding yeast has led to the discovery of novel functions for this complex in addition to its essential role at kinetochores. In G1/S cells, CBF3 components are detected along dynamic microtubules, where they can "search-and-capture" newly replicated centromeres. During anaphase, CBF3 is transported to the microtubule plus-ends of the spindle midzone. Consistent with this localization, cells containing a mutation in the CBF3 subunit Ndc10p show defects in spindle stability during anaphase. In addition, ndc10-1 cells show defects during cytokinesis, resulting in a defect in cell abscission. These results highlight the importance of midzone-targeted proteins in coordinating mitosis with cell division. Here we discuss these findings and explore the significance of CBF3 transport to microtubule plus-ends at the spindle midzone.Key words: spindle midzone, passenger protein, inner centromere protein (INCENP), microtubule plus-end.


2019 ◽  
Vol 88 (1) ◽  
pp. 661-689 ◽  
Author(s):  
Thomas D. Pollard ◽  
Ben O'Shaughnessy

Division of amoebas, fungi, and animal cells into two daughter cells at the end of the cell cycle depends on a common set of ancient proteins, principally actin filaments and myosin-II motors. Anillin, formins, IQGAPs, and many other proteins regulate the assembly of the actin filaments into a contractile ring positioned between the daughter nuclei by different mechanisms in fungi and animal cells. Interactions of myosin-II with actin filaments produce force to assemble and then constrict the contractile ring to form a cleavage furrow. Contractile rings disassemble as they constrict. In some cases, knowledge about the numbers of participating proteins and their biochemical mechanisms has made it possible to formulate molecularly explicit mathematical models that reproduce the observed physical events during cytokinesis by computer simulations.


2002 ◽  
Vol 13 (12) ◽  
pp. 4333-4342 ◽  
Author(s):  
Akira Nagasaki ◽  
Go Itoh ◽  
Shigehiko Yumura ◽  
Taro Q.P. Uyeda

We have cloned a full-length cDNA encoding a novel myosin II heavy chain kinase (mhckC) from Dictyostelium. Like other members of the myosin heavy chain kinase family, themhckC gene product, MHCK C, has a kinase domain in its N-terminal half and six WD repeats in the C-terminal half. GFP-MHCK C fusion protein localized to the cortex of interphase cells, to the cleavage furrow of mitotic cells, and to the posterior of migrating cells. These distributions of GFP-MHCK C always corresponded with that of myosin II filaments and were not observed in myosin II-null cells, where GFP-MHCK C was diffusely distributed in the cytoplasm. Thus, localization of MHCK C seems to be myosin II-dependent. Cells lacking the mhckC gene exhibited excessive aggregation of myosin II filaments in the cleavage furrows and in the posteriors of the daughter cells once cleavage was complete. The cleavage process of these cells took longer than that of wild-type cells. Taken together, these findings suggest MHCK C drives the disassembly of myosin II filaments for efficient cytokinesis and recycling of myosin II that occurs during cytokinesis.


2020 ◽  
Vol 219 (8) ◽  
Author(s):  
Bernardo Chapa-y-Lazo ◽  
Motonari Hamanaka ◽  
Alexander Wray ◽  
Mohan K. Balasubramanian ◽  
Masanori Mishima

Nearly six decades ago, Lewis Wolpert proposed the relaxation of the polar cell cortex by the radial arrays of astral microtubules as a mechanism for cleavage furrow induction. While this mechanism has remained controversial, recent work has provided evidence for polar relaxation by astral microtubules, although its molecular mechanisms remain elusive. Here, using C. elegans embryos, we show that polar relaxation is achieved through dynein-mediated removal of myosin II from the polar cortexes. Mutants that position centrosomes closer to the polar cortex accelerated furrow induction, whereas suppression of dynein activity delayed furrowing. We show that dynein-mediated removal of myosin II from the polar cortexes triggers a bidirectional cortical flow toward the cell equator, which induces the assembly of the actomyosin contractile ring. These results provide a molecular mechanism for the aster-dependent polar relaxation, which works in parallel with equatorial stimulation to promote robust cytokinesis.


2011 ◽  
Vol 193 (1) ◽  
pp. 155-169 ◽  
Author(s):  
Lindsay Lewellyn ◽  
Ana Carvalho ◽  
Arshad Desai ◽  
Amy S. Maddox ◽  
Karen Oegema

The chromosomal passenger complex (CPC) and centralspindlin are conserved cytokinesis regulators that localize to the spindle midzone, which forms between the separating chromosomes. Previous work placed the CPC and centralspindlin in a linear pathway that governs midzone formation. Using Caenorhabditis elegans embryos, we test whether there is a similar linear relationship between centralspindlin and the CPC in contractile ring constriction during cytokinesis. We show that simultaneous inhibition of the CPC kinase Aurora BAIR-2 and the centralspindlin component MKLP1ZEN-4 causes an additive constriction defect. Consistent with distinct roles for the proteins, inhibition of filamentous septin guanosine triphosphatases alleviates constriction defects in Aurora BAIR-2–inhibited embryos, whereas inhibition of Rac does so in MKLP1ZEN-4-inhibited embryos. Centralspindlin and the CPC are not required to enrich ring proteins at the cell equator but instead regulate formation of a compact mature ring. Therefore, in contrast to the linear midzone assembly pathway, centralspindlin and the CPC make independent contributions to control transformation of the sheet-like equatorial band into a ribbon-like contractile ring at the furrow tip.


2019 ◽  
Vol 218 (4) ◽  
pp. 1250-1264 ◽  
Author(s):  
Ingrid E. Adriaans ◽  
Angika Basant ◽  
Bas Ponsioen ◽  
Michael Glotzer ◽  
Susanne M.A. Lens

Cytokinesis begins upon anaphase onset. An early step involves local activation of the small GTPase RhoA, which triggers assembly of an actomyosin-based contractile ring at the equatorial cortex. Here, we delineated the contributions of PLK1 and Aurora B to RhoA activation and cytokinesis initiation in human cells. Knock-down of PRC1, which disrupts the spindle midzone, revealed the existence of two pathways that can initiate cleavage furrow ingression. One pathway depends on a well-organized spindle midzone and PLK1, while the other depends on Aurora B activity and centralspindlin at the equatorial cortex and can operate independently of PLK1. We further show that PLK1 inhibition sequesters centralspindlin onto the spindle midzone, making it unavailable for Aurora B at the equatorial cortex. We propose that PLK1 activity promotes the release of centralspindlin from the spindle midzone through inhibition of PRC1, allowing centralspindlin to function as a regulator of spindle midzone formation and as an activator of RhoA at the equatorial cortex.


2018 ◽  
Author(s):  
Ingrid E. Adriaans ◽  
Angika Basant ◽  
Bas Ponsioen ◽  
Michael Glotzer ◽  
Susanne M. A. Lens

AbstractCytokinesis starts in anaphase with the formation of an actomyosin-based contractile ring at the equatorial cortex, which is governed by the local activation of the small GTPase RhoA. Here we delineated the contributions of PLK1 and Aurora B to RhoA activation and cytokinesis initiation in human cells. Knock-down of PRC1, which disrupts the spindle midzone, revealed the existence of two pathways that can initiate cleavage furrow ingression. One pathway depends on a well-organized spindle midzone and PLK1, while the other depends on Aurora B activity and centralspindlin oligomerization at the equatorial cortex and can operate independently of PLK1. We further show that PLK1 inhibition sequesters centralspindlin onto the spindle midzone making it unavailable for Aurora B-dependent oligomerization at the equatorial cortex. We propose that PLK1 activity promotes the release of centralspindlin from the spindle midzone through inhibition of PRC1, allowing centralspindlin to function as a regulator of spindle midzone formation and as an activator of RhoA at the equatorial cortex.


2020 ◽  
Author(s):  
Alexandre Thomas ◽  
Emmanuel Gallaud ◽  
Aude Pascal ◽  
Laurence Serre ◽  
Isabelle Arnal ◽  
...  

AbstractNeuroblast (NB) cell division is characterized by a basal positioning of the cleavage furrow resulting in a large difference in size between the future daughter cells. In animal cells, furrow placement and assembly is governed by centralspindlin, a highly conserved complex that accumulates at the equatorial cell cortex of the future cleavage site and at the spindle midzone. In contrast to model systems studied so far, these two centralspindlin populations are spatially and temporally separated in NBs. A cortical leading pool is located at the basal cleavage furrow site and a second pool accumulates at the midzone before travelling to the site of the basal cleavage furrow during cytokinesis completion. By manipulating microtubule (MT) dynamics, we show that the cortical centralspindlin population requires peripheral astral microtubules and the Chromosome Passenger Complex (CPC) for efficient recruitment. Loss of this pool does not prevent cytokinesis but enhances centralspindlin levels at the midzone leading to furrow repositioning towards the equator and decreased size asymmetry between daughter cells. Together these data reveal that the asymmetrical furrow placement characteristic of NBs results from a competition between spatially and functionally separate centralspindlin pools in which the cortical pool is dominant and requires peripheral astral microtubules.


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