Transformation of taxol-stabilized microtubules into inverted tubulin tubules triggered by a tubulin conformation switch.

ABSTRACT: Bundles of taxol-stabilized microtubules (MTs)--hollow tubules comprised of assembled αβ-tubulin heterodimers--spontaneously assemble above a critical concentration of tetravalent spermine and are stable over long times at room temperature. Here we report that at concentrations of spermine several-fold higher the MT bundles (B(MT)) quickly become unstable and undergo a shape transformation to bundles of inverted tubulin tubules (B(ITT)), the outside surface of which corresponds to the inner surface of the B(MT) tubules. Using transmission electron microscopy and synchrotron small-angle X-ray scattering, we quantitatively determined both the nature of the B(MT)-to-B(ITT) transformation pathway, which results from a spermine-triggered conformation switch from straight to curved in the consti

SUBMITTER: Ojeda-Lopez MA 

PROVIDER: S-EPMC3946914 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature