Induction of a sheet polymer of tubulin by Zn2+

Larsson, Håkan; Wallin, Margareta; Edström, Anders

doi:10.1016/0014-4827(76)90332-3

Cited by 158 publications

(60 citation statements)

References 17 publications

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“…The structure and arrangement of the protofilaments in the sheets, and their relation to other microtubular structures, are not obvious from inspection of the unprocessed images. The patterns confirm the observations of Larsson et al (1976) and Crepeau et al (1977) that the subunit lattice is different from the surface lattice of opened out microtubules. Although the major intensities lie on layer-lines with a fundamental meridional repeat of about 40 A in both cases, the positions of the peaks along the layer-lines are different.…”

Section: Resultssupporting

confidence: 87%

“…However, the possibility of extending the resolution beyond about 20 A with such specimens is severely limited by the size of the sheets, which are seldom more than 10 to 13 protofilaments wide. The assembly of tub&n into much wider sheets, in the presence of low (less than millimolar) levels of zinc ions was first reported by Larsson et al (1976). Similar concentrations of magnesium ions appear to be essential for the assembly of normal microtubules : when magnesium is replaced by zinc, abnormally wide sheets, usually consisting of 20 to 50 protofilaments, are formed.…”

Section: Introductionmentioning

confidence: 90%

“…the minimum zinc concentrations required for the formation of Zn-induced sheets (see Larsson et al, 1976 and also Materials and Methods, section (a)) it is likely that a zinc ion is needed to bind to each tubulin monomer in order to directly or indirectly form the interprotofilament bonds. The fact that apparently similar protofilaments are common elements in such different structures reinforces the concept of the protofilament as an entity, supporting the idea that the protofilament is an intermediate structure in tubulin polymerization (Erickson, 1974b;Kirschner et al, 1974) and that the rings produced by disassembly consist of rolled-up protofilaments.…”

Section: Fig 4 (A) Images Of the Averagedmentioning

confidence: 99%

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Structure of the tubulin dimer in zinc-induced sheets

Baker

Amos

1978

Journal of Molecular Biology

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Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 90%

Section: Fig 4 (A) Images Of the Averagedmentioning

confidence: 99%

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Structure of the tubulin dimer in zinc-induced sheets

Baker

Amos

1978

Journal of Molecular Biology

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“…The amino acid composition of the mitochondrial crystal is also different from that of tubulin in having a higher content of glycine, alanine, cysteine, and particularly proline. The recently described tubulin aggregates (10) show a clearly different organization.…”

Section: Discussionmentioning

confidence: 90%

Protein of insect sperm mitochondrial crystals. Crystallomitin.

Baccetti¹,

Dallai²,

Pallini³

et al. 1977

The Journal of Cell Biology

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Mitochondrial derivatives of insect sperm usually contain a crystalline protein that shows a 45-nm main period, made up of 20-nm subperiods, determined by the coiling of filament bundles. Filaments are 2 nm thick and have a globular appearance. The crystals contain two main polypeptides, 52,000 and 55,000 daltons. These polypeptides are closely related, contain a high percentage of proline, and are insoluble in sodium dodecyl sulfate due to disulfide cross links. We suggest for this class of protein the name crystallomitin.Most insect spermatozoa are characterized by a prominent crystal (or crystalloid) in the matrix of their modified mitochondria. In some species the crystal may be of truly enormous dimensions, approaching or even exceeding 1 cm, and it may make up most of the volume of the spermatozoon (2, 15). It plays a particular role, therefore, in tail movement, and other functions for it have been suggested as well (2).It occurred to us that it should be possible to isolate these crystals and to characterize their contents by using standard chemical procedures. The obtained data could provide some information on the functional role and the evolution of insect sperm mitochondria. The present report shows the crystals to contain two main polypeptides, for which we propose the term "crystallomitin". MATERIALS AND METHODS Electron MicroscopyAdult backswimmers (Notonecta glauca L.) were caught in local ponds in the neighbourhood of Siena. Males were dissected in Hoyle's medium (0.375 g KC1, 3.750 g NaC1, 0.110 g CaCI2, 0.205 g MgCI2, 0.170 g NaHCO,~, 0.415 g NaH~PO4, 500 cm 3 H20), and spermatozoa from vasa deferentia were prepared in the following ways: (a) Spermatozoa were fixed in 4% paraformaldehyde and 5% glutaraldehyde at pH 7.2 in cacodylate buffer according to Karnovsky's method (8) for 1 h at 4~ The material was then rinsed overnight in cacodylate buffer, post-fixed in 1% osmium tetroxide for 1 h, dehydrated in a graded ethanol series, and embedded in Epon. Thin sections were stained with uranyl acetate and lead citrate. (b) Spermatozoa were treated with 0.5 M EDTA for 5 h. After centrifugation, the material was rinsed in distilled water and fixed in 2.5% glutaraldehyde in Hoyle's medium, dehydrated, and embedded in Epon. (c) Spermatozoa were treated with 1% sodium dodecyl sulfate (SDS) in 0.75 M Tris HCI, pH 8.8, for 30 min, fixed as in (a), rinsed overnight in cacodylate buffer, postfixed, and embedded as in (a). (d) Spermatozoa were treated with EDTA as in (b), and subsequently with 0.1% SDS for 40 min. Fixation and embedding were carded out as in (c). For making negatively stained preparations, a drop of sperm dispersion was placed on a coated grid and washed with distilled water. A drop of 1.5% uranyl acetate or 1% phosphotungstic acid (PTA) at pH 6-7.2 was then added to the grid, the excess fluid was removed, and the preparation was allowed to air dry.For freeze-etching the vasa deferentia were incubated for 1 h at 4~ in 25% glycerol in Hoyle's medium, transferred to small gold disks, a...

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“…It is well known that Zn2+ interferes with brain microtubules both in vitro [7] and in situ [8]. Tubulin has one high affinity site for Zn2+ [9].…”

Section: Introductionmentioning

confidence: 99%

The effect of S‐100a and S‐100b proteins and Zn²⁺ on the assembly of brain microtubule proteins in vitro

Deinum¹,

Baudier²,

Briving³

et al. 1983

FEBS Letters

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The homologous proteins S-1OOa and S-1OOb affect the microtubule system in a distinctly different way in the presence of low molar ratios of Zn a+ Assembly of brain microtubule proteins can be almost . completely inhibited and rapid disassembly can be induced by low molar amounts of S-1OOb in the presence of low molar ratios 12-41 of Zn". Higher molar ratios per S-1OOb (>4) potentiate the general Zn*+ effect, promoting the formation of sheets of microtubules. However, the effect of S-1OOa is quite different, no inhibition of assembly can be observed and the presence of S-1OOa seems to protect the microtubule proteins against the effect of Zn2" by chelating the Zn2+ and decreasing the free metal-ion concentration. S-1OOa or S-iOOb cannot bind to the microtubule polymer-form, either in the absence or in the presence of Zn2+. Microtubule assemblyTub&in S-100 protein Calmodulin Zn2+ regulation

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Induction of a sheet polymer of tubulin by Zn2+

Cited by 158 publications

References 17 publications

Structure of the tubulin dimer in zinc-induced sheets

Structure of the tubulin dimer in zinc-induced sheets

Protein of insect sperm mitochondrial crystals. Crystallomitin.

The effect of S‐100a and S‐100b proteins and Zn²⁺ on the assembly of brain microtubule proteins in vitro

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Induction of a sheet polymer of tubulin by Zn2+

Cited by 158 publications

References 17 publications

Structure of the tubulin dimer in zinc-induced sheets

Structure of the tubulin dimer in zinc-induced sheets

Protein of insect sperm mitochondrial crystals. Crystallomitin.

The effect of S‐100a and S‐100b proteins and Zn2+ on the assembly of brain microtubule proteins in vitro

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The effect of S‐100a and S‐100b proteins and Zn²⁺ on the assembly of brain microtubule proteins in vitro