Microtubule Formation in vitro in Solutions Containing Low Calcium Concentrations

  title={Microtubule Formation in vitro in Solutions Containing Low Calcium Concentrations},
  author={Richard C. Weisenberg},
  pages={1104 - 1105}
  • R. Weisenberg
  • Published 22 September 1972
  • Chemistry, Medicine
  • Science
Isolated rat brain tubulin can be repolymerized in vitro in solutions containing adenosine triphosphate or guanosine triphosphate, magnesium ions, and a good calcium chelator. The extreme sensitivity of tubulin to calcium ions explains the failure of previous efforts to obtain polymerization and suggests a possible mechanism for regulation of microtubule polymerization in vivo. 
Microtubule formation and the initial association of tubulin dimers
Tubulin after isolation showed an association equilibrium in the presence of glutamate (or other zwitterions), but not in phosphate buffers, suggesting that this association to tetramers is probably the initial step in the mechanism of microtubule formation.
The in vitro assembly of microtubules from purified brain tubulin
Abstract Purified calf brain tubulin can assemble into microtubules according to a nucleated polymerization mechanism. This reaction is enhanced by proteins copurfied with tubulin, various
Microtubule formation by pure brain tubulin in vitro. The influence of dextran and poly(ethylene glycol).
Homogeneous brain tubulin, free of microtubule associated proteins, forms microtubules in polymerization buffers containing 7.5--15% dextran T10 or 2--4.5% poly(ethylene glycol) type 6000, which are sensitive to colchicine and low temperature.
Calcium binding to bovine brain tubulin
Microtubules are present in a wide variety of eucaryotic cells and it was recently shown that the reassembly in vitro of brain microtubular protein (tubulin) can be reversibly controlled by calcium
Alterations in number of protofilaments in microtubules assembled in vitro
Tubulin from bovine brain was polymerized in vitro using a variety of assembly conditions. Many of the formed microtubules were shown to contain 14 wall protofilaments. The number of microtubules
Pressure-induced depolymerization of brain microtubules in vitro.
Brain microtubules assembled in vitro from tubulin extracted from rabbit brain were subjected to changes in hydrostatic pressure and temperature, and the characteristic response of brain micro Tubulin in vitro to pressure is similar to that of mitotic spindle microtubule in vivo.
Magnesium stimulation of calcium binding to tubulin and calcium induced depolymerization of microtubules
The inhibition of polymerization by Ca is a function of the concentrations of Mg ions present, and data has been obtained indicating that Ca binds directly to tubulin, and that binding is enhanced by Mg.
Purification of brain tubulin through two cycles of polymerization-depolymerization in a high-molarity buffer.
It is shown that only two cycles of polymerization-depolymerization of pig brain tubulin in the presence of a high-molarity PIPES buffer allow the efficient removal of contaminating proteins and production of ahigh-concentration tubulin solution.
In vitro formation of filaments from calf brain microtubule protein.
Abstract Electron micrographs of filaments formed by purified calf brain tubulin show structures with a uniform cross-section diameter of 29 ± 3 nm, similar to that of native microtubules. Exposure
Interaction of Calcium-Calmodulin in Microtubule Assembly in Vitro
In most eukaryotic cells, microtubules, intermediate filaments, and microfilaments constitute a fibrous network that is termed the cytoskeleton. Microtubules have been implicated in a number of cell


  • R. Kane
  • Biology, Medicine
    The Journal of cell biology
  • 1962
The isolation of the mitotic apparatus (MA) from the echinoderm egg was studied in detail, with particular attention given to the factors governing its stability. Successful isolation depends mainly