Focusing-in on microtubules

Amos, Linda

doi:10.1016/s0959-440x(00)00070-1

Cited by 64 publications

(33 citation statements)

References 58 publications

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“…Microtubules are hollow tubes consisting of ␣-and ␤-tubulin heterodimers that polymerize parallel to a cylindrical axis (1). Microtubules are critical elements in a variety of fundamental cell functions, including sustained shape, transportation of vesicles and protein complexes, and regulation of motility and cell division (2).…”

Section: Introductionmentioning

confidence: 99%

BPR0L075, a Novel Synthetic Indole Compound with Antimitotic Activity in Human Cancer Cells, Exerts Effective Antitumoral Activityin Vivo

Kuo¹,

Hsieh

Pan³

et al. 2004

Cancer Research

192

187

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Section: Introductionmentioning

confidence: 99%

BPR0L075, a Novel Synthetic Indole Compound with Antimitotic Activity in Human Cancer Cells, Exerts Effective Antitumoral Activityin Vivo

Kuo¹,

Hsieh

Pan³

et al. 2004

Cancer Research

192

187

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“…3). Peptide ␤408-418 (H12) is located at the surface of the microtubule and participates in the binding of MAPs (microtubule-associated proteins) (27). In this instance, despite the high purity of our tubulin preparation, we cannot exclude the possible presence of trace amounts of contaminating MAPs that could protect this region from HDX.…”

mentioning

confidence: 99%

Insights into the mechanism of microtubule stabilization by Taxol

Xiao

Verdier-Pinard²,

Fernández-Fuentes³

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

276

250

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The antitumor drug Taxol stabilizes microtubules and reduces their dynamicity, promoting mitotic arrest and cell death. Upon assembly of the ␣͞␤-tubulin heterodimer, GTP bound to ␤-tubulin is hydrolyzed to GDP reaching a steady-state equilibrium between free tubulin dimers and microtubules. The binding of Taxol to ␤-tubulin in the polymer results in cold-stable microtubules at the expense of tubulin dimers, even in the absence of exogenous GTP. However, there is little biochemical insight into the mechanism(s) by which Taxol stabilizes microtubules. Here, we analyze the structural changes occurring in both ␤-and ␣-tubulin upon microtubule stabilization by Taxol. Hydrogen͞deuterium exchange (HDX) coupled to liquid chromatography-electrospray ionization MS demonstrated a marked reduction in deuterium incorporation in both ␤-and ␣-tubulin when Taxol was present. Decreased local HDX in peptic peptides was mapped on the tubulin structure and revealed both expected and new dimer-dimer interactions. The increased rigidity in Taxol microtubules was distinct from and complementary to that due to GTP-induced polymerization. The Taxol-induced changes in tubulin conformation act against microtubule depolymerization in a precise directional way. These results demonstrate that HDX coupled to liquid chromatography-electrospray ionization MS can be effectively used to study conformational effects induced by small ligands on microtubules. The present study also opens avenues for locating drug and protein binding sites and for deciphering the mechanisms by which their interactions alter the conformation of microtubules and tubulin dimers.hydrogen͞deuterium exchange

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“…52 Such studies now reveal that dimeric Klps interact primarily to β-tubulin near paired helices 11 and 12 on the surface. [53][54][55][56] The recent structure of γ-tubulin indicates similarly oriented helices. 57 By comparative analysis of tubulins from nine model eukaryotes, we identified a subset of conserved residues in helix 11 of γ-tubulins that is shared with β-tubulins and distinct from α-tubulins.…”

Section: Discussionmentioning

confidence: 99%

Protein complexes at the microtubule organizing center regulate bipolar spindle assembly

Rodriguez¹,

Batac²,

Killilea³

et al. 2008

Cell Cycle

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Bipolar spindle assembly is essential to genomic stability in dividing cells. Centrosomes or spindle pole bodies duplicated earlier at G 1 /S remain adjacent until triggered at mitotic onset to become bipolar. Pole reorientation is stabilized by microtubule interdigitation but mechanistic details for bipolarity remain incomplete. To investigate the contribution of spindle pole microtubule organizing center (MTOC) proteins in bipolarity, we applied genetic, structural and molecular biochemical analysis along with timelapse microscopy. Spindle formation was followed by an in vivo growth assay with the conditional allele cut7-22 ts , encoding fission yeast mitotic Kinesin-5, essential for bipolarity. By analysis of double and triple mutant strains of MTOC alleles and cut7-22 ts we found that stabilized microtubules or increased bundling can rescue cut7-22 ts associated bipolarity defects. These changes to microtubule dynamics and organization occurred through two surface domains on γ-tubulin, a helix 11 domain and an adjacent site for binding MTOC protein Alp4. We demonstrate that Kinesin-14 Pkl1, known to oppose bipolarity, can bind to γ-tubulin at helix 11 and that mutation of either of two conserved residues in helix 11 can impair Kinesin-14 binding. Altering the Alp4/γ-tubulin interaction, conserved residues in helix 11 or deletion of pkl1 each are sufficient to rescue bipolarity in our cut7-22 ts strain. Our findings provide novel insights into regulation of the bipolar mechanism through the MTOC complex.

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Focusing-in on microtubules

Cited by 64 publications

References 58 publications

BPR0L075, a Novel Synthetic Indole Compound with Antimitotic Activity in Human Cancer Cells, Exerts Effective Antitumoral Activityin Vivo

BPR0L075, a Novel Synthetic Indole Compound with Antimitotic Activity in Human Cancer Cells, Exerts Effective Antitumoral Activityin Vivo

Insights into the mechanism of microtubule stabilization by Taxol

Protein complexes at the microtubule organizing center regulate bipolar spindle assembly

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