The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Reinhard Fischer - One of the best experts on this subject based on the ideXlab platform.
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role of the spindle pole body protein apsb and the cortex protein apsa in Microtubule organization and nuclear migration in aspergillus nidulans
Journal of Cell Science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation ΔkinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
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Role of the spindle-pole-body protein ApsB and the cortex protein ApsA in Microtubule organization and nuclear migration in Aspergillus nidulans.
Journal of cell science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation DeltakinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
Daniel Veith - One of the best experts on this subject based on the ideXlab platform.
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role of the spindle pole body protein apsb and the cortex protein apsa in Microtubule organization and nuclear migration in aspergillus nidulans
Journal of Cell Science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation ΔkinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
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Role of the spindle-pole-body protein ApsB and the cortex protein ApsA in Microtubule organization and nuclear migration in Aspergillus nidulans.
Journal of cell science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation DeltakinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
Bungo Akiyoshi - One of the best experts on this subject based on the ideXlab platform.
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the kinetoplastid kinetochore protein kkt4 is an unconventional Microtubule tip coupling protein
Journal of Cell Biology, 2018Co-Authors: Aida Llauro, Hanako Hayashi, Megan E Bailey, Alexander C Wilson, Patryk Ludzia, Charles L Asbury, Bungo AkiyoshiAbstract:: Kinetochores are multiprotein machines that drive chromosome segregation by maintaining persistent, load-bearing linkages between chromosomes and dynamic Microtubule tips. Kinetochores in commonly studied eukaryotes bind Microtubules through widely conserved components like the Ndc80 complex. However, in evolutionarily divergent kinetoplastid species such as Trypanosoma brucei, which causes sleeping sickness, the kinetochores assemble from a unique set of proteins lacking homology to any known Microtubule-binding domains. Here, we show that the T. brucei kinetochore protein KKT4 binds directly to Microtubules and maintains load-bearing attachments to both growing and shortening Microtubule tips. The protein localizes both to kinetochores and to spindle Microtubules in vivo, and its depletion causes defects in chromosome segregation. We define a Microtubule-binding domain within KKT4 and identify several charged residues important for its Microtubule-binding activity. Thus, despite its lack of significant similarity to other known Microtubule-binding proteins, KKT4 has key functions required for driving chromosome segregation. We propose that it represents a primary element of the kinetochore-Microtubule interface in kinetoplastids.
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the unconventional kinetoplastid kinetochore protein kkt4 tracks with dynamic Microtubule tips
bioRxiv, 2017Co-Authors: Aida Llauro, Hanako Hayashi, Megan E Bailey, Alexander C Wilson, Patryk Ludzia, Charles L Asbury, Bungo AkiyoshiAbstract:Kinetochores are multiprotein machines that drive chromosome segregation in all eukaryotes by maintaining persistent, load-bearing linkages between the chromosomes and the tips of dynamic spindle Microtubules. Kinetochores in commonly studied eukaryotes are assembled from widely conserved components like the Ndc80 complex that directly binds Microtubules. However, in evolutionarily-divergent kinetoplastid species such as Trypanosoma brucei, which causes sleeping sickness, the kinetochores assemble from a unique set of proteins lacking homology to any known Microtubule-binding domains. Here we show that a kinetochore protein from T. brucei called KKT4 binds directly to Microtubules, diffuses along the Microtubule lattice, and tracks with disassembling Microtubule tips. The protein localizes both to kinetochores and to spindle Microtubules in vivo, and its depletion causes defects in chromosome segregation. We define a minimal Microtubule-binding domain within KKT4 and identify several charged residues important for its Microtubule-binding activity. Laser trapping experiments show that KKT4 can maintain load-bearing attachments to both growing and shortening Microtubule tips. Thus, despite its lack of similarity to other known Microtubule-binding proteins, KKT4 has key functions required for harnessing Microtubule dynamics to drive chromosome segregation. We propose that it represents a primary element of the kinetochore-Microtubule interface in kinetoplastids.
Vladimir P Efimov - One of the best experts on this subject based on the ideXlab platform.
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role of the spindle pole body protein apsb and the cortex protein apsa in Microtubule organization and nuclear migration in aspergillus nidulans
Journal of Cell Science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation ΔkinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
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Role of the spindle-pole-body protein ApsB and the cortex protein ApsA in Microtubule organization and nuclear migration in Aspergillus nidulans.
Journal of cell science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation DeltakinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
Nicole Scherr - One of the best experts on this subject based on the ideXlab platform.
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role of the spindle pole body protein apsb and the cortex protein apsa in Microtubule organization and nuclear migration in aspergillus nidulans
Journal of Cell Science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation ΔkinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
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Role of the spindle-pole-body protein ApsB and the cortex protein ApsA in Microtubule organization and nuclear migration in Aspergillus nidulans.
Journal of cell science, 2005Co-Authors: Daniel Veith, Nicole Scherr, Vladimir P Efimov, Reinhard FischerAbstract:Nuclear migration and positioning in Aspergillus nidulans depend on Microtubules, the Microtubule-dependent motor protein dynein, and auxiliary proteins, two of which are ApsA and ApsB. In apsA and apsB mutants nuclei are clustered and show various kinds of nuclear navigation defects, although nuclear migration itself is still possible. We studied the role of several components involved in nuclear migration through in vivo fluorescence microscopy using fluorescent-protein tagging. Because ApsA localizes to the cell cortex and mitotic spindles were immobile in apsA mutants, we suggest that astral Microtubule-cortex interactions are necessary for oscillation and movement of mitotic spindles along hyphae, but not for post-mitotic nuclear migration. Mutation of apsA resulted in longer and curved Microtubules and displayed synthetic lethality in combination with the conventional kinesin mutation DeltakinA. By contrast, ApsB localized to spindle-pole bodies (the fungal centrosome), to septa and to spots moving rapidly along Microtubules. The number of cytoplasmic Microtubules was reduced in apsB mutants in comparison to the wild type, indicating that cytoplasmic Microtubule nucleation was affected, whereas mitotic spindle formation appeared normal. Mutation of apsB suppressed dynein null mutants, whereas apsA mutation had no effect. We suggest that nuclear positioning defects in the apsA and apsB mutants are due to different effects on microtbule organisation. A model of spindle-pole body led nuclear migration and the roles of dynein and Microtubules are discussed.
