Limits...
The Drosophila gene abnormal spindle encodes a novel microtubule-associated protein that associates with the polar regions of the mitotic spindle.

Saunders RD, Avides MC, Howard T, Gonzalez C, Glover DM - J. Cell Biol. (1997)

Bottom Line: Wild-type Asp protein copurifies with microtubules and is not released by salt concentrations known to dissociate most other microtubule-associated proteins.The central 579-amino acid segment of the molecule contains one short motif homologous to sequences in a number of actin bundling proteins and a second motif present at the calmodulin binding sites of several proteins.Immunofluorescence studies show that the wild-type Asp protein is localized to the polar regions of the spindle immediately surrounding the centrosome.

View Article: PubMed Central - PubMed

Affiliation: Cancer Research Campaign, Cell Cycle Genetics Group, Department of Anatomy and Physiology, University of Dundee, Dundee DD1 4HN, Scotland.

ABSTRACT
abnormal spindle, a gene required for normal spindle structure and function in Drosophila melanogaster, lies immediately adjacent the gene tolloid at 96A/B. It encodes a 220-kD polypeptide with a predicted pI of 10.8. The recessive mutant allele asp1 directs the synthesis of a COOH terminally truncated or internally deleted peptide of approximately 124 kD. Wild-type Asp protein copurifies with microtubules and is not released by salt concentrations known to dissociate most other microtubule-associated proteins. The bacterially expressed NH2-terminal 512-amino acid peptide, which has a number of potential phosphorylation sites for p34(cdc2) and MAP kinases, strongly binds to microtubules. The central 579-amino acid segment of the molecule contains one short motif homologous to sequences in a number of actin bundling proteins and a second motif present at the calmodulin binding sites of several proteins. Immunofluorescence studies show that the wild-type Asp protein is localized to the polar regions of the spindle immediately surrounding the centrosome. These findings are discussed in relation to the known spindle abnormalities in asp mutants.

Show MeSH

Related in: MedlinePlus

Immunolocalization of Asp in the mitotic cycle in syncytial embryos. Simultaneous staining for DNA with propidium iodide  and tubulin with YL1/2 primary antibody and rhodamine-conjugated goat anti–rat IgG are shown in the first column and subsequent red  channel of the merged image. Staining of Asp using Rb3133 primary antibody and FITC-conjugated goat anti–rabbit IgG is shown in the  middle column and subsequent green channel in the merged image. The mitotic phases are (a) interphase, (b) prophase, (c) metaphase,  (d) anaphase, and (e) telophase. The scale bar refers to the main set of panels. Single mitotic figures have been selected for the inset at a  fourfold greater magnification. Bar, 25 μm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2139842&req=5

Figure 8: Immunolocalization of Asp in the mitotic cycle in syncytial embryos. Simultaneous staining for DNA with propidium iodide and tubulin with YL1/2 primary antibody and rhodamine-conjugated goat anti–rat IgG are shown in the first column and subsequent red channel of the merged image. Staining of Asp using Rb3133 primary antibody and FITC-conjugated goat anti–rabbit IgG is shown in the middle column and subsequent green channel in the merged image. The mitotic phases are (a) interphase, (b) prophase, (c) metaphase, (d) anaphase, and (e) telophase. The scale bar refers to the main set of panels. Single mitotic figures have been selected for the inset at a fourfold greater magnification. Bar, 25 μm.

Mentions: Mutations in asp affect the morphology of both the mitotic spindle at several developmental stages and the meiotic spindle. At all stages mutant spindle microtubules may be described as having a long and wavy appearance, and it is not uncommon to see the loss of bipolarity in the form of hemispindle structures. To determine whether Asp protein is a constituent of the wild-type spindle we used the Rb3133 antibody to localize the Asp protein with respect to microtubules in mitosis in syncytial embryos (Fig. 8). During interphase, Asp protein appears to be distributed throughout the cytoplasm (Fig. 8 a), but as the syncytium enters mitosis and the bipolar spindle is formed, Asp is seen in association with the polar regions (Fig. 8 b). This polar association becomes tighter throughout metaphase and anaphase (Fig. 8, c and d), but at telophase, as the chromatin is decondensing and the spindle begins to disassemble, the Asp protein appears to move away from the region occupied by the centrosome onto the central region of the spindle microtubules.


The Drosophila gene abnormal spindle encodes a novel microtubule-associated protein that associates with the polar regions of the mitotic spindle.

Saunders RD, Avides MC, Howard T, Gonzalez C, Glover DM - J. Cell Biol. (1997)

Immunolocalization of Asp in the mitotic cycle in syncytial embryos. Simultaneous staining for DNA with propidium iodide  and tubulin with YL1/2 primary antibody and rhodamine-conjugated goat anti–rat IgG are shown in the first column and subsequent red  channel of the merged image. Staining of Asp using Rb3133 primary antibody and FITC-conjugated goat anti–rabbit IgG is shown in the  middle column and subsequent green channel in the merged image. The mitotic phases are (a) interphase, (b) prophase, (c) metaphase,  (d) anaphase, and (e) telophase. The scale bar refers to the main set of panels. Single mitotic figures have been selected for the inset at a  fourfold greater magnification. Bar, 25 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2139842&req=5

Figure 8: Immunolocalization of Asp in the mitotic cycle in syncytial embryos. Simultaneous staining for DNA with propidium iodide and tubulin with YL1/2 primary antibody and rhodamine-conjugated goat anti–rat IgG are shown in the first column and subsequent red channel of the merged image. Staining of Asp using Rb3133 primary antibody and FITC-conjugated goat anti–rabbit IgG is shown in the middle column and subsequent green channel in the merged image. The mitotic phases are (a) interphase, (b) prophase, (c) metaphase, (d) anaphase, and (e) telophase. The scale bar refers to the main set of panels. Single mitotic figures have been selected for the inset at a fourfold greater magnification. Bar, 25 μm.
Mentions: Mutations in asp affect the morphology of both the mitotic spindle at several developmental stages and the meiotic spindle. At all stages mutant spindle microtubules may be described as having a long and wavy appearance, and it is not uncommon to see the loss of bipolarity in the form of hemispindle structures. To determine whether Asp protein is a constituent of the wild-type spindle we used the Rb3133 antibody to localize the Asp protein with respect to microtubules in mitosis in syncytial embryos (Fig. 8). During interphase, Asp protein appears to be distributed throughout the cytoplasm (Fig. 8 a), but as the syncytium enters mitosis and the bipolar spindle is formed, Asp is seen in association with the polar regions (Fig. 8 b). This polar association becomes tighter throughout metaphase and anaphase (Fig. 8, c and d), but at telophase, as the chromatin is decondensing and the spindle begins to disassemble, the Asp protein appears to move away from the region occupied by the centrosome onto the central region of the spindle microtubules.

Bottom Line: Wild-type Asp protein copurifies with microtubules and is not released by salt concentrations known to dissociate most other microtubule-associated proteins.The central 579-amino acid segment of the molecule contains one short motif homologous to sequences in a number of actin bundling proteins and a second motif present at the calmodulin binding sites of several proteins.Immunofluorescence studies show that the wild-type Asp protein is localized to the polar regions of the spindle immediately surrounding the centrosome.

View Article: PubMed Central - PubMed

Affiliation: Cancer Research Campaign, Cell Cycle Genetics Group, Department of Anatomy and Physiology, University of Dundee, Dundee DD1 4HN, Scotland.

ABSTRACT
abnormal spindle, a gene required for normal spindle structure and function in Drosophila melanogaster, lies immediately adjacent the gene tolloid at 96A/B. It encodes a 220-kD polypeptide with a predicted pI of 10.8. The recessive mutant allele asp1 directs the synthesis of a COOH terminally truncated or internally deleted peptide of approximately 124 kD. Wild-type Asp protein copurifies with microtubules and is not released by salt concentrations known to dissociate most other microtubule-associated proteins. The bacterially expressed NH2-terminal 512-amino acid peptide, which has a number of potential phosphorylation sites for p34(cdc2) and MAP kinases, strongly binds to microtubules. The central 579-amino acid segment of the molecule contains one short motif homologous to sequences in a number of actin bundling proteins and a second motif present at the calmodulin binding sites of several proteins. Immunofluorescence studies show that the wild-type Asp protein is localized to the polar regions of the spindle immediately surrounding the centrosome. These findings are discussed in relation to the known spindle abnormalities in asp mutants.

Show MeSH
Related in: MedlinePlus