Tubulins from Plants, Fungi, and Protists

Morejohn, Louis C.; Fosket, Donald E.

doi:10.1007/978-1-4613-2151-4_11

Cited by 39 publications

(25 citation statements)

References 376 publications

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“…Indeed, the functional consequences of these substitutions cannot be predicted a priori, so information must also be derived from direct examination of plant microtubule protein function. Although few studies exist on the regulation of plant microbutule polymerization, methods to isolate, purify, and polymerize plant tubulin (Morejohn and Fosket, 1982;Bokros et al, 1993) have facilitated studies showing that plant and mammalian tubulins are structurally, immunologically, and pharmacologically distinct (Morejohn et al, 1984;Morejohn and Fosket, 1986;Fosket and Morejohn, 1992;Hugdahl and Morejohn, 1993). We have recently shown that taxol-induced polymerization of plant tubulin proceeds more effectively, even at low temperature, and has a lower critical concentration than mammalian tubulin (Bokros et al, 1993).…”

Section: Polymerization Depends Upon a Critical Concentration (C) Ofmentioning

confidence: 99%

Unique functional characteristics of the polymerization and MAP binding regulatory domains of plant tubulin.

et al. 1993

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An understanding of the regulation of microtubule polymerization and dynamics in plant cells requires biochemical information on the structures, functions, and molecular interactions of plant tubulin and microtubule-associated proteins (MAPs) that regulate microtubule function. We have probed the regulatory domain and polymerization domain of purified maize tubulin using MAP2, an extensively characterized mammalian neumnal MAP. MAP2 bound to the surface of preformed, taxol-stabilized maize microtubules, with binding saturation occurring with one MAP2 molecule per five to six tubulin dimers, as it does with mammalian microtubules. MAP2 binding and dissociation analyses revealed two affinity classes of binding sites on maize microtubules: a high-affinity site 12 dimers apart that may be homologous to the cognate mammalian MAP2 binding site and an additional low-affinity site also 12 dimers apart that may be homologous to the mammalian tau binding site. MAPS corrected in vitro folding errors in taxol-stabilized maize microtubules and reduced the critical concentration of maize tubulin polymerization eightfold, from 8.3 to 1.0 pM. However, MAPS dissociated much more readily from maize microtubules than from mammalian microtubules and induced the assembly of maize tubulin into aberrant helical ribbon polymers that remained stable for prolonged periods. Our results indicated that MAPS binds to maize tubulin via a partially specific, low-fidelity interaction that reflects unique structural and functional properties of the polymerization and regulatory domains of plant tubulin and possibly of the tubulin binding domains of undocumented MAPs that regulate microtubule function in plant cells.

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Section: Polymerization Depends Upon a Critical Concentration (C) Ofmentioning

confidence: 99%

Unique functional characteristics of the polymerization and MAP binding regulatory domains of plant tubulin.

et al. 1993

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“…Most recently, oryzalin was used to study the regulation of tubulin synthesis after depolymerization of microtubules in the ciliated protoctistan Tetrahymena thermophila (Stargell et al, 1992). In these different groups of organisms, millimolar colchicine concentrations are required to produce antimicrotubule effects similar to those obtained with low micromolar or nanomolar levels of oryzalin, apparently because their tubulins have a low affinity for colchicine (Morejohn and Fosket, 1986).…”

mentioning

confidence: 99%

Rapid and Reversible High-Affinity Binding of the Dinitroaniline Herbicide Oryzalin to Tubulin from Zea mays L

1993

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“…Several agents that affect microtubule integrity were assayed for inhibition of nuclear fusion. Amiprophos-methyl and oryzalin cause depolymerization of microtubules in higher plants (27)(28)(29). Gametic cells were treated with 5 uM amiprophos-methyl and 10luM oryzalin for 4 hr before mating and for 5 hr after mixing gametic cells.…”

Section: Methodsmentioning

confidence: 99%

Nuclear fusion-defective phenocopies in Chlamydomonas reinhardtii: mating-type functions for meiosis can act through the cytoplasm.

Dutcher

1988

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

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Nuclear fusion in newly formed Chlamydomonas reinhardtii zygotes can be inhibited by drugs that affect microtubule stability, which include colchicine, amiprophosmethyl, oryzalin, and taxol. This inhibition can be monitored genetically by the production of haploid meiotic products from conjugations between haploid and diploid parents. Such zygotes would normally produce aneuploid progeny. Inhibition of nuclear fusion by colchicine requires treatment of gametic cells both before conjugation and after formation of the zygotes.These results suggest that nuclear fusion requires dynamic microtubules. Treated zygotes formed from a haploid-diploid mating can produce six spores, but only four spores germinate to form viable haploid colonies. No contribution from the nuclear genome of the haploid parent is recovered, whereas all loci from the diploid parent are recovered. The four viable products from the diploid parent of inhibited zygotes show normal segregation of loci located on linkage groups segregating according to Mendelian laws. Levels of meiotic recombination were tested for pairs of loci on linkage groups XVIII and XIX and found to be unchanged by inhibition of nuclear fusion. Thus, similar to Saccharomyces cerevisiae, C. reinhard mating-type functions necessary for nuclear fusion are not nuclear limited and can act through the cytoplasm. Inhibition of nuclear fusion can be used to analyze diploid Chlamydomonas that cannot enter meiosis. This technique permits direct analysis of dominant mutations, dominant suppressors and enhancers, and new alleles of identified loci that have been isolated in diploid strains.

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Tubulins from Plants, Fungi, and Protists

Cited by 39 publications

References 376 publications

Unique functional characteristics of the polymerization and MAP binding regulatory domains of plant tubulin.

Unique functional characteristics of the polymerization and MAP binding regulatory domains of plant tubulin.

Rapid and Reversible High-Affinity Binding of the Dinitroaniline Herbicide Oryzalin to Tubulin from Zea mays L

Nuclear fusion-defective phenocopies in Chlamydomonas reinhardtii: mating-type functions for meiosis can act through the cytoplasm.

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