Dynein and dynactin are localized to astral microtubules and at cortical sites in mitotic epithelial cells

Busson, Sylvie; Dujardin, Denis; Moreau, Anne; Dompierre, Jim; Mey, Jan R. De

doi:10.1016/s0960-9822(98)70208-8

Cited by 237 publications

(210 citation statements)

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“…This is in agreement with the observation that astral microtubules organized from mitotic centrosomes are required for spindle positioning and determination of the cleavage furrow (Rieder et al, 2001). This is accomplished through interactions of microtubule tips with cortical dynein/dynactin (Busson et al, 1998). Because DdCP224-elicited supernumerary centrosomes behaved like fully competent MTOCs, they could also participate in cleavage furrow formation.…”

Section: Control Of Supernumerary Centrosome Numbersupporting

confidence: 90%

Regulated Expression of the Centrosomal Protein DdCP224 Affects Microtubule Dynamics and Reveals Mechanisms for the Control of Supernumerary Centrosome Number

Gräf

Euteneuer

et al. 2003

MBoC

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The Dictyostelium XMAP215 family member DdCP224 is involved in centrosome duplication and cytokinesis and is concentrated at the centrosome and microtubule tips. Herein, we have created a DdCP224 promoter replacement mutant that allows both over-and underexpression. Overexpression led to supernumerary microtubule-organizing centers and, independently, an increase of the number of multinuclear cells. Electron microscopy demonstrated that supernumerary microtubule-organizing centers represented bona fide centrosomes. Live cell imaging of DdCP224-green fluorescent protein mutants also expressing green fluorescent protein-histone2B as a DNA label revealed that supernumerary centrosomes were also competent of cell cycle-dependent duplication. In contrast, underexpression of DdCP224 inhibited cell growth, reduced the number and length of astral microtubules, and caused nocodazole hypersensitivity. Moreover, microtubule regrowth after nocodazole removal was dependent on DdCP224. Underexpression also resulted in a striking disappearance of supernumerary centrosomes and multinuclear cells caused by previous overexpression. We show for the first time by live cell observation that the number of supernumerary centrosomes can be reduced either by centrosome fusion (coalescence) or by the formation of cytoplasts containing supernumerary centrosomes during cytokinesis. INTRODUCTIONIn dividing cells, control of centrosome number is essential for the fidelity of mitosis and maintenance of euploidy. Supernumerary centrosomes are a hallmark of tumor cells, although it is still a matter of discussion whether their appearance is a cause or a consequence of carcinogenesis (Lingle et al., 2002;Nigg, 2002). However, it is widely accepted that supernumerary centrosomes contribute to the formation of multipolar spindles and thus to defective chromosome segregation. Although most of the daughter cells resulting from such mitotic chaos will die, some of them will acquire the potential for neoplastic growth in spite of supernumerary centrosomes and aneuploidy, as they regain the ability to form a bipolar spindle. Brinkley (2001) suggested two mechanisms how this can be achieved: first, "deamplification" of supernumerary centrosomes by elimination or inactivation, and second, fusion or "coalescence" of supernumerary centrosomes resulting in one or two compound microtubule-organizing centers (MTOCs).Herein, we have studied the fate of supernumerary centrosomes in a simple model system. In Dictyostelium amoebae, one molecular component involved in the formation of supernumerary centrosomes is DdCP224, a member of the XMAP215 family of microtubule-associated proteins (Gräf et al., 2000). In most species, these proteins are long, thin, monomeric molecules with a size of ϳ 230 kDa (Cassimeris et al., 2001). Their ubiquitous occurrence, even in plants, suggests indispensible functions (Ohkura et al., 2001). XMAP215, for instance, is a promoter of microtubule elongation due to a suppression of catastrophe events induced by the Kin I family kinesin ...

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Section: Control Of Supernumerary Centrosome Numbersupporting

confidence: 90%

Regulated Expression of the Centrosomal Protein DdCP224 Affects Microtubule Dynamics and Reveals Mechanisms for the Control of Supernumerary Centrosome Number

Gräf

Euteneuer

et al. 2003

MBoC

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“…Diffuse staining is also seen on the central spindle but not at the poles after NEB ( Figure 2C). For unknown reasons, this localization for the dynein heavy chain in Drosophila early embryos is different than that reported previously , although similar cortical staining has been observed in vertebrate epithelial cells (Busson et al, 1998). Possible explanations for this observation include that anti-DHC is specific for a distinct dynein isoform or recognizes a site on the same dynein isoform that is masked unless the motor is bound to specific cellular targets such as the cortex.…”

Section: Antagonistic Microtubule Motors Involved In Spindle Pole Migcontrasting

confidence: 63%

Functional Coordination of Three Mitotic Motors inDrosophilaEmbryos

Sharp

Brown

Kwon

et al. 2000

MBoC

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It is well established that multiple microtubule-based motors contribute to the formation and function of the mitotic spindle, but how the activities of these motors interrelate remains unclear.Here we visualize spindle formation in living Drosophila embryos to show that spindle pole movements are directed by a temporally coordinated balance of forces generated by three mitotic motors, cytoplasmic dynein, KLP61F, and Ncd. Specifically, our findings suggest that dynein acts to move the poles apart throughout mitosis and that this activity is augmented by KLP61F after the fenestration of the nuclear envelope, a process analogous to nuclear envelope breakdown, which occurs at the onset of prometaphase. Conversely, we find that Ncd generates forces that pull the poles together between interphase and metaphase, antagonizing the activity of both dynein and KLP61F and serving as a brake for spindle assembly. During anaphase, however, Ncd appears to have no effect on spindle pole movements, suggesting that its activity is downregulated at this time, allowing dynein and KLP61F to drive spindle elongation during anaphase B. INTRODUCTIONThe segregation of chromosomes during mitosis depends on the action of a self-organizing, bipolar machine called the mitotic spindle. It is now established that the formation and function of the mitotic spindle requires numerous microtubule (MT)-based motor proteins (Hoyt and Geiser, 1996;Vale and Fletterick, 1997). Although the identities of many of these mitotic motors are becoming clear, their specific functional interrelationships have been extremely difficult to ascertain.Among all mitotic movements, the positioning of spindle poles during the assembly and elongation of the bipolar mitotic spindle may require the greatest degree of cooperation between different motors. This process is particularly complex because it occurs in a pathway consisting of several, temporally distinct stages, during which the organization of spindle microtubules and the general environment of the cell change dramatically (McIntosh and McDonald, 1989). The members of at least three families of MT motors are thought to play important roles in this pathway. These are the bipolar kinesins, the C-terminal kinesins, and cytoplasmic dynein.The bipolar (or BimC) kinesins (Vale and Fletterick, 1997) comprise a family of plus-end-directed motors, which have a bipolar morphology with motor domains at both ends of a central rod (Cole et al., 1994; Kashina et al., 1996a,b; Gordon and Roof, 2000). Functionally, these motors are thought to play a role in either the assembly or maintenance of spindle bipolarity, because their inhibition results in the formation of monopolar mitotic spindles (Enos and Morris, 1990;Hagan and Yanagida, 1990;Roof et al., 1991;Hoyt et al., 1992;Sawin et al., 1992;Heck et al., 1993;Blangy et al., 1995;Sharp et al., 1999b). Support for a role for bipolar kinesins in spindle maintenance but not assembly comes from the recent findings that inhibiting the Drosophila bipolar kinesin KLP61F does not pr...

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“…The cortical localization of dynein-dynactin in mammalian cells, which plays an important role in spindle positioning, requires F-actin (Busson et al, 1998;Dujardin and Vallee, 2002). It is involved in attaching spindle body to the cortical actin through dynactin, which facilitates nuclear movement along the microtubule into the daughter cell in S. cerevisiae and in several other fungi (Yamamoto and Hiraoka, 2003;for review).…”

Section: Dlc1 Regulates Dynein-dynactin Function Involved In Nuclear mentioning

confidence: 99%

Dynein Light Chain 1 Regulates Dynamin-mediated F-Actin Assembly during Sperm Individualization inDrosophila

Ghosh-Roy

Desai

Ray

2005

MBoC

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Toward the end of spermiogenesis, spermatid nuclei are compacted and the clonally related spermatids individualize to become mature and active sperm. Studies in Drosophila showed that caudal end-directed movement of a microfilamentrich structure, called investment cone, expels the cytoplasmic contents of individual spermatids. F-actin dynamics plays an important role in this process. Here we report that the dynein light chain 1 (DLC1) of Drosophila is involved in two separate cellular processes during sperm individualization. It is enriched around spermatid nuclei during postelongation stages and plays an important role in the dynein-dynactin-dependent rostral retention of the nuclei during this period. In addition, DDLC1 colocalizes with dynamin along investment cones and regulates F-actin assembly at this organelle by retaining dynamin along the cones. Interestingly, we found that this process does not require the other subunits of cytoplasmic dynein-dynactin complex. Altogether, these observations suggest that DLC1 could independently regulate multiple cellular functions and established a novel role of this protein in F-actin assembly in Drosophila. INTRODUCTIONSperm elongation and maturation involves complex choreography of a range of different cytoskeletal events leading to a large-scale alteration of cell shape and bulk membrane movement. One of the unique features of sperm differentiation is the clearing of cytoplasmic contents of spermatids after elongation, which also separates them as individual sperm. It is a key step to form mature and active sperm. Morphogenetic changes associated with sperm individualization have been studied in detail in Drosophila (reviewed by Lindsley and Tokuyasu, 1980). It involves compaction of the nuclei, formation of the microfilament rich investment cones around the nucleus, and extrusion of cytoplasmic contents of each spermatid by a caudal end-directed movement of the investment cone. In comparison, the molecular mechanisms underlying these processes are not so well understood.F-actin and Lamin are the two known cytoskeleton components of investment cone, also known as F-actin cone (Fabrizio et al., 1998;Arama et al., 2003). Pharmacological treatments of isolated cysts established that F-actin dynamics plays a critical role in membrane extraction and F-actin cone movement and that both these processes are microtubule independent (Noguchi and Miller, 2003). F-actin-associated proteins, such as capping protein, cortactin, Arp2/3 complex, and myosin VI, are enriched at the leading edges of F-actin cones, whereas dynamin is localized throughout (Rogat and Miller, 2002), indicating that F-actin assembly would be initiated at the leading edges. Although, a later study showed that the F-actin assembly occurs throughout the cone (Noguchi and Miller, 2003). The F-actin cone bundles appeared disrupted in myosin VI homozygous testes (Hicks et al., 1999) and genetic interaction studies showed that myosin VI (jar 1 ) and dynamin (shi ts1 ) could act in parallel pathways to maintain t...

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Dynein and dynactin are localized to astral microtubules and at cortical sites in mitotic epithelial cells

Cited by 237 publications

References 19 publications

Regulated Expression of the Centrosomal Protein DdCP224 Affects Microtubule Dynamics and Reveals Mechanisms for the Control of Supernumerary Centrosome Number

Regulated Expression of the Centrosomal Protein DdCP224 Affects Microtubule Dynamics and Reveals Mechanisms for the Control of Supernumerary Centrosome Number

Functional Coordination of Three Mitotic Motors inDrosophilaEmbryos

Dynein Light Chain 1 Regulates Dynamin-mediated F-Actin Assembly during Sperm Individualization inDrosophila

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