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Herman H W Sillje - One of the best experts on this subject based on the ideXlab platform.
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the plk1 dependent phosphoproteome of the early Mitotic Spindle
Molecular & Cellular Proteomics, 2011Co-Authors: Anna Santamaria, Herman H W Sillje, Roman Korner, Bin Wang, Sabine Elowe, Rainer Malik, Feng Zhang, Manuel Bauer, Alexander Schmidt, Erich A NiggAbstract:Polo-like kinases regulate many aspects of Mitotic and meiotic progression from yeast to man. In early mitosis, mammalian Polo-like kinase 1 (Plk1) controls centrosome maturation, Spindle assembly, and microtubule attachment to kinetochores. However, despite the essential and diverse functions of Plk1, the full range of Plk1 substrates remains to be explored. To investigate the Plk1-dependent phosphoproteome of the human Mitotic Spindle, we combined stable isotope labeling by amino acids in cell culture with Plk1 inactivation or depletion followed by Spindle isolation and mass spectrometry. Our study identified 358 unique Plk1-dependent phosphorylation sites on Spindle proteins, including novel substrates, illustrating the complexity of the Plk1-dependent signaling network. Over 100 sites were validated by in vitro phosphorylation of peptide arrays, resulting in a broadening of the Plk1 consensus motif. Collectively, our data provide a rich source of information on Plk1-dependent phosphorylation, Plk1 docking to substrates, the influence of phosphorylation on protein localization, and the functional interaction between Plk1 and Aurora A on the early Mitotic Spindle.
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phosphoproteome analysis of the human Mitotic Spindle
Proceedings of the National Academy of Sciences of the United States of America, 2006Co-Authors: Marjaana Nousiainen, Herman H W Sillje, Guido Sauer, Erich A Nigg, Roman KornerAbstract:During cell division, the Mitotic Spindle segregates the sister chromatids into two nascent cells, such that each daughter cell inherits one complete set of chromosomes. Errors in Spindle formation can result in both chromosome missegregation and cytokinesis defects and hence lead to genomic instability. To ensure the correct function of the Spindle, the activity and localization of Spindle associated proteins has to be tightly regulated in time and space. Reversible phosphorylation has been shown to be one of the key regulatory mechanisms for the organization of the Mitotic Spindle. The relatively low number of identified in vivo phosphorylation sites of Spindle components, however, has hampered functional analysis of regulatory Spindle networks. A more complete inventory of the phosphorylation sites of Spindle-associated proteins would therefore constitute an important advance. Here, we describe the mass spectrometry-based identification of in vivo phosphorylation sites from purified human Mitotic Spindles. In total, 736 phosphorylation sites were identified, of which 312 could be attributed to known Spindle proteins. Among these are phosphorylation sites that were previously shown to be important for the regulation of Spindle-associated proteins. Importantly, this data set also comprises 279 novel phosphorylation sites of known Spindle proteins for future functional studies. This inventory of Spindle phosphorylation sites should thus make an important contribution to a better understanding of the molecular mechanisms that regulate the formation, function, and integrity of the Mitotic Spindle.
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Phosphoproteome analysis of the human Mitotic Spindle
Proceedings of the National Academy of Sciences, 2006Co-Authors: Marjaana Nousiainen, Herman H W Sillje, Guido Sauer, Erich A Nigg, Roman KornerAbstract:During cell division, the Mitotic Spindle segregates the sister chromatids into two nascent cells, such that each daughter cell inherits one complete set of chromosomes. Errors in Spindle formation can result in both chromosome missegregation and cytokinesis defects and hence lead to genomic instability. To ensure the correct function of the Spindle, the activity and localization of Spindle associated proteins has to be tightly regulated in time and space. Reversible phosphorylation has been shown to be one of the key regulatory mechanisms for the organization of the Mitotic Spindle. The relatively low number of identified in vivo phosphorylation sites of Spindle components, however, has hampered functional analysis of regulatory Spindle networks. A more complete inventory of the phosphorylation sites of Spindle-associated proteins would therefore constitute an important advance. Here, we describe the mass spectrometry-based identification of in vivo phosphorylation sites from purified human Mitotic Spindles. In total, 736 phosphorylation sites were identified, of which 312 could be attributed to known Spindle proteins. Among these are phosphorylation sites that were previously shown to be important for the regulation of Spindle-associated proteins. Importantly, this data set also comprises 279 novel phosphorylation sites of known Spindle proteins for future functional studies. This inventory of Spindle phosphorylation sites should thus make an important contribution to a better understanding of the molecular mechanisms that regulate the formation, function, and integrity of the Mitotic Spindle.
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proteome analysis of the human Mitotic Spindle
Molecular & Cellular Proteomics, 2005Co-Authors: Guido Sauer, Erich A Nigg, Roman Korner, Anja Hanisch, Albert Ries, Herman H W SilljeAbstract:The accurate distribution of sister chromatids during cell division is crucial for the generation of two cells with the same complement of genetic information. A highly dynamic microtubule-based structure, the Mitotic Spindle, carries out the physical separation of the chromosomes to opposite poles of the cells and, moreover, determines the cell division cleavage plane. In animal cells, the Spindle comprises microtubules that radiate from the microtubule organizing centers, the centrosomes, and interact with kinetochores on the chromosomes. Malfunctioning of the Spindle can lead to chromosome missegregation and hence result in aneuploidy, a hallmark of most human cancers. Despite major progress in deciphering the temporal and spatial regulation of the Mitotic Spindle, its composition and function are not fully understood. A more complete inventory of Spindle components would therefore constitute an important advance. Here we describe the purification of human Mitotic Spindles and their analysis by MS/MS. We identified 151 proteins previously known to associate with the Spindle apparatus, centrosomes, and/or kinetochores and 644 other proteins, including 154 uncharacterized components that did not show obvious homologies to known proteins and did not contain motifs indicative of a particular localization. Of these uncharacterized proteins, 17 were tagged and localized in transfected Mitotic cells, resulting in the identification of six genuine Spindle components (KIAA0008, CdcA8, KIAA1187, FLJ12649, FLJ90806, and C20Orf129). This study illustrates the strength of a proteomic approach for the analysis of isolated human Spindles and identifies several novel Spindle components for future functional studies.
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Regulation of Aurora-A kinase on the Mitotic Spindle
Chromosoma, 2003Co-Authors: Thomas A. Kufer, Erich A Nigg, Herman H W SilljeAbstract:The error-free segregation of duplicated chromosomes during cell division is essential for the maintenance of an intact genome. This process is brought about by a highly dynamic bipolar array of microtubules, the Mitotic Spindle. The formation and function of the Mitotic Spindle during M-phase of the cell cycle is regulated by protein phosphorylation, involving multiple protein kinases and phosphatases. Prominent among the enzymes implicated in Spindle assembly is the serine/threonine-specific protein kinase Aurora-A. In several common human tumors, Aurora-A is overexpressed, and deregulation of this kinase was shown to result in Mitotic defects and aneuploidy. Moreover, recent genetic evidence directly links the human Aurora-A gene to cancer susceptibility. Several of the physiological substrates of Aurora-A presumably await identification, but recent studies are beginning to shed light on the regulation of this critical Mitotic kinase. Here, we review these findings with particular emphasis on the role of TPX2, a prominent Spindle component implicated in a Ran-GTP-mediated Spindle assembly pathway.
Erich A Nigg - One of the best experts on this subject based on the ideXlab platform.
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the plk1 dependent phosphoproteome of the early Mitotic Spindle
Molecular & Cellular Proteomics, 2011Co-Authors: Anna Santamaria, Herman H W Sillje, Roman Korner, Bin Wang, Sabine Elowe, Rainer Malik, Feng Zhang, Manuel Bauer, Alexander Schmidt, Erich A NiggAbstract:Polo-like kinases regulate many aspects of Mitotic and meiotic progression from yeast to man. In early mitosis, mammalian Polo-like kinase 1 (Plk1) controls centrosome maturation, Spindle assembly, and microtubule attachment to kinetochores. However, despite the essential and diverse functions of Plk1, the full range of Plk1 substrates remains to be explored. To investigate the Plk1-dependent phosphoproteome of the human Mitotic Spindle, we combined stable isotope labeling by amino acids in cell culture with Plk1 inactivation or depletion followed by Spindle isolation and mass spectrometry. Our study identified 358 unique Plk1-dependent phosphorylation sites on Spindle proteins, including novel substrates, illustrating the complexity of the Plk1-dependent signaling network. Over 100 sites were validated by in vitro phosphorylation of peptide arrays, resulting in a broadening of the Plk1 consensus motif. Collectively, our data provide a rich source of information on Plk1-dependent phosphorylation, Plk1 docking to substrates, the influence of phosphorylation on protein localization, and the functional interaction between Plk1 and Aurora A on the early Mitotic Spindle.
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phosphoproteome analysis of the human Mitotic Spindle
Proceedings of the National Academy of Sciences of the United States of America, 2006Co-Authors: Marjaana Nousiainen, Herman H W Sillje, Guido Sauer, Erich A Nigg, Roman KornerAbstract:During cell division, the Mitotic Spindle segregates the sister chromatids into two nascent cells, such that each daughter cell inherits one complete set of chromosomes. Errors in Spindle formation can result in both chromosome missegregation and cytokinesis defects and hence lead to genomic instability. To ensure the correct function of the Spindle, the activity and localization of Spindle associated proteins has to be tightly regulated in time and space. Reversible phosphorylation has been shown to be one of the key regulatory mechanisms for the organization of the Mitotic Spindle. The relatively low number of identified in vivo phosphorylation sites of Spindle components, however, has hampered functional analysis of regulatory Spindle networks. A more complete inventory of the phosphorylation sites of Spindle-associated proteins would therefore constitute an important advance. Here, we describe the mass spectrometry-based identification of in vivo phosphorylation sites from purified human Mitotic Spindles. In total, 736 phosphorylation sites were identified, of which 312 could be attributed to known Spindle proteins. Among these are phosphorylation sites that were previously shown to be important for the regulation of Spindle-associated proteins. Importantly, this data set also comprises 279 novel phosphorylation sites of known Spindle proteins for future functional studies. This inventory of Spindle phosphorylation sites should thus make an important contribution to a better understanding of the molecular mechanisms that regulate the formation, function, and integrity of the Mitotic Spindle.
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Phosphoproteome analysis of the human Mitotic Spindle
Proceedings of the National Academy of Sciences, 2006Co-Authors: Marjaana Nousiainen, Herman H W Sillje, Guido Sauer, Erich A Nigg, Roman KornerAbstract:During cell division, the Mitotic Spindle segregates the sister chromatids into two nascent cells, such that each daughter cell inherits one complete set of chromosomes. Errors in Spindle formation can result in both chromosome missegregation and cytokinesis defects and hence lead to genomic instability. To ensure the correct function of the Spindle, the activity and localization of Spindle associated proteins has to be tightly regulated in time and space. Reversible phosphorylation has been shown to be one of the key regulatory mechanisms for the organization of the Mitotic Spindle. The relatively low number of identified in vivo phosphorylation sites of Spindle components, however, has hampered functional analysis of regulatory Spindle networks. A more complete inventory of the phosphorylation sites of Spindle-associated proteins would therefore constitute an important advance. Here, we describe the mass spectrometry-based identification of in vivo phosphorylation sites from purified human Mitotic Spindles. In total, 736 phosphorylation sites were identified, of which 312 could be attributed to known Spindle proteins. Among these are phosphorylation sites that were previously shown to be important for the regulation of Spindle-associated proteins. Importantly, this data set also comprises 279 novel phosphorylation sites of known Spindle proteins for future functional studies. This inventory of Spindle phosphorylation sites should thus make an important contribution to a better understanding of the molecular mechanisms that regulate the formation, function, and integrity of the Mitotic Spindle.
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proteome analysis of the human Mitotic Spindle
Molecular & Cellular Proteomics, 2005Co-Authors: Guido Sauer, Erich A Nigg, Roman Korner, Anja Hanisch, Albert Ries, Herman H W SilljeAbstract:The accurate distribution of sister chromatids during cell division is crucial for the generation of two cells with the same complement of genetic information. A highly dynamic microtubule-based structure, the Mitotic Spindle, carries out the physical separation of the chromosomes to opposite poles of the cells and, moreover, determines the cell division cleavage plane. In animal cells, the Spindle comprises microtubules that radiate from the microtubule organizing centers, the centrosomes, and interact with kinetochores on the chromosomes. Malfunctioning of the Spindle can lead to chromosome missegregation and hence result in aneuploidy, a hallmark of most human cancers. Despite major progress in deciphering the temporal and spatial regulation of the Mitotic Spindle, its composition and function are not fully understood. A more complete inventory of Spindle components would therefore constitute an important advance. Here we describe the purification of human Mitotic Spindles and their analysis by MS/MS. We identified 151 proteins previously known to associate with the Spindle apparatus, centrosomes, and/or kinetochores and 644 other proteins, including 154 uncharacterized components that did not show obvious homologies to known proteins and did not contain motifs indicative of a particular localization. Of these uncharacterized proteins, 17 were tagged and localized in transfected Mitotic cells, resulting in the identification of six genuine Spindle components (KIAA0008, CdcA8, KIAA1187, FLJ12649, FLJ90806, and C20Orf129). This study illustrates the strength of a proteomic approach for the analysis of isolated human Spindles and identifies several novel Spindle components for future functional studies.
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Regulation of Aurora-A kinase on the Mitotic Spindle
Chromosoma, 2003Co-Authors: Thomas A. Kufer, Erich A Nigg, Herman H W SilljeAbstract:The error-free segregation of duplicated chromosomes during cell division is essential for the maintenance of an intact genome. This process is brought about by a highly dynamic bipolar array of microtubules, the Mitotic Spindle. The formation and function of the Mitotic Spindle during M-phase of the cell cycle is regulated by protein phosphorylation, involving multiple protein kinases and phosphatases. Prominent among the enzymes implicated in Spindle assembly is the serine/threonine-specific protein kinase Aurora-A. In several common human tumors, Aurora-A is overexpressed, and deregulation of this kinase was shown to result in Mitotic defects and aneuploidy. Moreover, recent genetic evidence directly links the human Aurora-A gene to cancer susceptibility. Several of the physiological substrates of Aurora-A presumably await identification, but recent studies are beginning to shed light on the regulation of this critical Mitotic kinase. Here, we review these findings with particular emphasis on the role of TPX2, a prominent Spindle component implicated in a Ran-GTP-mediated Spindle assembly pathway.
Roman Korner - One of the best experts on this subject based on the ideXlab platform.
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the plk1 dependent phosphoproteome of the early Mitotic Spindle
Molecular & Cellular Proteomics, 2011Co-Authors: Anna Santamaria, Herman H W Sillje, Roman Korner, Bin Wang, Sabine Elowe, Rainer Malik, Feng Zhang, Manuel Bauer, Alexander Schmidt, Erich A NiggAbstract:Polo-like kinases regulate many aspects of Mitotic and meiotic progression from yeast to man. In early mitosis, mammalian Polo-like kinase 1 (Plk1) controls centrosome maturation, Spindle assembly, and microtubule attachment to kinetochores. However, despite the essential and diverse functions of Plk1, the full range of Plk1 substrates remains to be explored. To investigate the Plk1-dependent phosphoproteome of the human Mitotic Spindle, we combined stable isotope labeling by amino acids in cell culture with Plk1 inactivation or depletion followed by Spindle isolation and mass spectrometry. Our study identified 358 unique Plk1-dependent phosphorylation sites on Spindle proteins, including novel substrates, illustrating the complexity of the Plk1-dependent signaling network. Over 100 sites were validated by in vitro phosphorylation of peptide arrays, resulting in a broadening of the Plk1 consensus motif. Collectively, our data provide a rich source of information on Plk1-dependent phosphorylation, Plk1 docking to substrates, the influence of phosphorylation on protein localization, and the functional interaction between Plk1 and Aurora A on the early Mitotic Spindle.
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phosphoproteome analysis of the human Mitotic Spindle
Proceedings of the National Academy of Sciences of the United States of America, 2006Co-Authors: Marjaana Nousiainen, Herman H W Sillje, Guido Sauer, Erich A Nigg, Roman KornerAbstract:During cell division, the Mitotic Spindle segregates the sister chromatids into two nascent cells, such that each daughter cell inherits one complete set of chromosomes. Errors in Spindle formation can result in both chromosome missegregation and cytokinesis defects and hence lead to genomic instability. To ensure the correct function of the Spindle, the activity and localization of Spindle associated proteins has to be tightly regulated in time and space. Reversible phosphorylation has been shown to be one of the key regulatory mechanisms for the organization of the Mitotic Spindle. The relatively low number of identified in vivo phosphorylation sites of Spindle components, however, has hampered functional analysis of regulatory Spindle networks. A more complete inventory of the phosphorylation sites of Spindle-associated proteins would therefore constitute an important advance. Here, we describe the mass spectrometry-based identification of in vivo phosphorylation sites from purified human Mitotic Spindles. In total, 736 phosphorylation sites were identified, of which 312 could be attributed to known Spindle proteins. Among these are phosphorylation sites that were previously shown to be important for the regulation of Spindle-associated proteins. Importantly, this data set also comprises 279 novel phosphorylation sites of known Spindle proteins for future functional studies. This inventory of Spindle phosphorylation sites should thus make an important contribution to a better understanding of the molecular mechanisms that regulate the formation, function, and integrity of the Mitotic Spindle.
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Phosphoproteome analysis of the human Mitotic Spindle
Proceedings of the National Academy of Sciences, 2006Co-Authors: Marjaana Nousiainen, Herman H W Sillje, Guido Sauer, Erich A Nigg, Roman KornerAbstract:During cell division, the Mitotic Spindle segregates the sister chromatids into two nascent cells, such that each daughter cell inherits one complete set of chromosomes. Errors in Spindle formation can result in both chromosome missegregation and cytokinesis defects and hence lead to genomic instability. To ensure the correct function of the Spindle, the activity and localization of Spindle associated proteins has to be tightly regulated in time and space. Reversible phosphorylation has been shown to be one of the key regulatory mechanisms for the organization of the Mitotic Spindle. The relatively low number of identified in vivo phosphorylation sites of Spindle components, however, has hampered functional analysis of regulatory Spindle networks. A more complete inventory of the phosphorylation sites of Spindle-associated proteins would therefore constitute an important advance. Here, we describe the mass spectrometry-based identification of in vivo phosphorylation sites from purified human Mitotic Spindles. In total, 736 phosphorylation sites were identified, of which 312 could be attributed to known Spindle proteins. Among these are phosphorylation sites that were previously shown to be important for the regulation of Spindle-associated proteins. Importantly, this data set also comprises 279 novel phosphorylation sites of known Spindle proteins for future functional studies. This inventory of Spindle phosphorylation sites should thus make an important contribution to a better understanding of the molecular mechanisms that regulate the formation, function, and integrity of the Mitotic Spindle.
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proteome analysis of the human Mitotic Spindle
Molecular & Cellular Proteomics, 2005Co-Authors: Guido Sauer, Erich A Nigg, Roman Korner, Anja Hanisch, Albert Ries, Herman H W SilljeAbstract:The accurate distribution of sister chromatids during cell division is crucial for the generation of two cells with the same complement of genetic information. A highly dynamic microtubule-based structure, the Mitotic Spindle, carries out the physical separation of the chromosomes to opposite poles of the cells and, moreover, determines the cell division cleavage plane. In animal cells, the Spindle comprises microtubules that radiate from the microtubule organizing centers, the centrosomes, and interact with kinetochores on the chromosomes. Malfunctioning of the Spindle can lead to chromosome missegregation and hence result in aneuploidy, a hallmark of most human cancers. Despite major progress in deciphering the temporal and spatial regulation of the Mitotic Spindle, its composition and function are not fully understood. A more complete inventory of Spindle components would therefore constitute an important advance. Here we describe the purification of human Mitotic Spindles and their analysis by MS/MS. We identified 151 proteins previously known to associate with the Spindle apparatus, centrosomes, and/or kinetochores and 644 other proteins, including 154 uncharacterized components that did not show obvious homologies to known proteins and did not contain motifs indicative of a particular localization. Of these uncharacterized proteins, 17 were tagged and localized in transfected Mitotic cells, resulting in the identification of six genuine Spindle components (KIAA0008, CdcA8, KIAA1187, FLJ12649, FLJ90806, and C20Orf129). This study illustrates the strength of a proteomic approach for the analysis of isolated human Spindles and identifies several novel Spindle components for future functional studies.
Rebecca Heald - One of the best experts on this subject based on the ideXlab platform.
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RanGTP and CLASP1 cooperate to position the Mitotic Spindle.
Molecular Biology of the Cell, 2013Co-Authors: Stephen L. Bird, Rebecca Heald, Karsten WeisAbstract:Accurate positioning of the Mitotic Spindle is critical to ensure proper distribution of chromosomes during cell division. The small GTPase Ran, which regulates a variety of processes throughout the cell cycle, including interphase nucleocytoplasmic transport and Mitotic Spindle assembly, was recently shown to also control Spindle alignment. Ran is required for the correct cortical localization of LGN and nuclear-Mitotic apparatus protein (NuMA), proteins that generate pulling forces on astral microtubules (MTs) through cytoplasmic dynein. Here we use importazole, a small-molecule inhibitor of RanGTP/importin-β function, to study the role of Ran in Spindle positioning in human cells. We find that importazole treatment results in defects in astral MT dynamics, as well as in mislocalization of LGN and NuMA, leading to misoriented Spindles. Of interest, importazole-induced Spindle-centering defects can be rescued by nocodazole treatment, which depolymerizes astral MTs, or by overexpression of CLASP1, which does not restore proper LGN and NuMA localization but stabilizes astral MT interactions with the cortex. Together our data suggest a model for Mitotic Spindle positioning in which RanGTP and CLASP1 cooperate to align the Spindle along the long axis of the dividing cell.
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Mitotic Spindle Assembly Mechanisms
The Kinetochore:, 2008Co-Authors: Rebecca Heald, Claire E. WalczakAbstract:The Mitotic Spindle consists of dynamic microtubules and many associated factors that form an antiparallel, bipolar array. Duplicated chromosomes are attached to microtubules of the Spindle and then are physically separated by the Spindle to opposite ends of the dividing cell. Spindles vary in their morphology and assembly pathway depending on the cell type and organism, but common underlying mechanisms derive from the dynamics of the microtubules and microtubule-based motor proteins, and the activities of chromosomes themselves. In this chapter, we describe the multiple mechanisms that promote assembly of the dynamic Mitotic Spindle.
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the rangtp gradient a gps for the Mitotic Spindle
Journal of Cell Science, 2008Co-Authors: Petr Kalab, Rebecca HealdAbstract:The GTPase Ran has a key role in nuclear import and export, Mitotic Spindle assembly and nuclear envelope formation. The cycling of Ran between its GTP- and GDP-bound forms is catalyzed by the chromatin-bound guanine nucleotide exchange factor RCC1 and the cytoplasmic Ran GTPase-activating protein RanGAP. The result is an intracellular concentration gradient of RanGTP that equips eukaryotic cells with a `genome-positioning system9 (GPS). The binding of RanGTP to nuclear transport receptors (NTRs) of the importin β superfamily mediates the effects of the gradient and generates further downstream gradients, which have been elucidated by fluorescence resonance energy transfer (FRET) imaging and computational modeling. The Ran-dependent GPS spatially directs many functions required for genome segregation by the Mitotic Spindle during mitosis. Through exportin 1, RanGTP recruits essential centrosome and kinetochore components, whereas the RanGTP-induced release of Spindle assembly factors (SAFs) from importins activates SAFs to nucleate, bind and organize nascent Spindle microtubules. Although a considerable fraction of cytoplasmic SAFs is active and RanGTP induces only partial further activation near chromatin, bipolar Spindle assembly is robustly induced by cooperativity and positive-feedback mechanisms within the network of Ran-activated SAFs. The RanGTP gradient is conserved, although its roles vary among different cell types and species, and much remains to be learned regarding its functions.
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a rae1 containing ribonucleoprotein complex is required for Mitotic Spindle assembly
Cell, 2005Co-Authors: Michael D Blower, Rebecca Heald, Maxence V Nachury, Karsten WeisAbstract:Summary Centrosome-independent microtubule polymerization around chromosomes has been shown to require a local gradient of RanGTP, which discharges Mitotic cargoes from the nuclear import receptor importin β. Here, we have used an activity-based assay in Xenopus egg extracts to purify the mRNA export protein Rae1 as a Spindle assembly factor regulated by this pathway. Rae1 is a microtubule-associated protein that binds directly to importin β. Depletion of Rae1 from extracts or cells severely inhibits Mitotic Spindle assembly. A purified Rae1 complex stabilizes microtubules in egg extracts in a RanGTP/importin β-regulated manner. Interestingly, Rae1 exists in a large ribonucleoprotein complex, which requires RNA for its activity to control microtubule dynamics in vitro. Furthermore, we provide evidence that RNA associates with the Mitotic Spindle and that it plays a direct, translation-independent role in Spindle assembly. Our studies reveal an unexpected function for RNA in Spindle morphogenesis.
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Mitotic Spindle assembly in vitro.
Current protocols in cell biology editorial board Juan S. Bonifacino ... [et al.], 2001Co-Authors: J Merlie, Rebecca HealdAbstract:The protocols in this unit describe the preparation of materials for an in vitro assay of Mitotic Spindle assembly in Xenopus egg extracts. Fluorochrome-labeled tubulin is used to visualize microtubule asters and Spindles.
Jonathan M. Scholey - One of the best experts on this subject based on the ideXlab platform.
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Sliding filaments and Mitotic Spindle organization
Nature Cell Biology, 2014Co-Authors: Haifeng Wang, Ingrid Brust-mascher, Jonathan M. ScholeyAbstract:Mitosis depends upon the action of the Mitotic Spindle, a subcellular machine that uses microtubules (MTs) and motors to assemble itself and to coordinate chromosome segregation. Recent work illuminates how the motor-driven poleward sliding of MTs — nucleated at centrosomes, chromosomes and on pre-existing MTs — contributes to Spindle assembly and length control.
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Control of Mitotic Spindle Length
Annual Review of Cell and Developmental Biology, 2010Co-Authors: Gohta Goshima, Jonathan M. ScholeyAbstract:The Mitotic Spindle accurately segregates genetic instructions by moving chromosomes to Spindle poles (anaphase A) and separating the poles (anaphase B) so that, in general, the chromosomes and poles are positioned near the centers of the nascent daughter cell products of each cell division. Because the size of different types of dividing cells, and thus the spacing of their daughter cell centers, can vary significantly, the length of the metaphase or postanaphase B Spindle often scales with cell size. However, significant exceptions to this scaling rule occur, revealing the existence of cell size–independent, Spindle-associated mechanisms of Spindle length control. The control of Spindle length reflects the action of Mitotic force-generating mechanisms, and its study may illuminate general principles by which cells regulate the size of internal structures. Here we review molecules and mechanisms that control Spindle length, how these mechanisms are deployed in different systems, and some quantitative models that describe the control of Spindle length.