REVERSAL BY LIGHT OF THE ACTION OF <i>N</i>-METHYL <i>N</i>-DESACETYL COLCHICINE ON MITOSIS

Aronson, John F.; Inoué, Shinya

doi:10.1083/jcb.45.2.470

Cited by 79 publications

(21 citation statements)

References 5 publications

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“…Furthermore, during dialysis, those subunits from which colchicine was released would begin to aggregate. To separate the colchicine-removal step from subsequent polymerization, ultraviolet light (UV) irradiation was used (12,13). Colchicine, when irradiated with long-wave ultraviolet light, is photochemically converted to lumi-colchicine (11,18); lumi-colchicine has no measureable affinity for microtubule subunits (19).…”

Section: Resultsmentioning

confidence: 99%

“…For experiments in which colchicine was first bound to the purified subunits and then removed by conversion to lumicolchicine by long-wave ultraviolet irradiation (11)(12)(13), the following procedure was used. One part (gram wet weight) of the 60% (NH4)2SO4 pellet was suspended in 3 volumes of KPO4-KCl-GTP containing 100 ,.M colchicine, homogenized to obtain a uniform suspension, and incubated at 370 for 45 min.…”

Section: Protocols For Polymerization Experimentsmentioning

confidence: 99%

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In Vitro Aggregation of Cytoplasmic Microtubule Subunits

Borisy

Olmsted

Klugman

1972

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

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The colchicine-binding protein in porcinebrain tissue is a dimer of molecular weight 110,000 that is believed to be the subunit of neuronal microtubules. Conditions are established under which the dimers aggregate with reproducible kinetics. This aggregation reaction, which is monitored by development of turbidity, has the following characteristics: (a) Colchicine inhibits development of turbidity; (b) the reaction inhibited by colchicine is reversed by long-wave ultraviolet irradiation; (c) the aggregation is temperature-dependent; (d) the reaction is nucleotide triphosphate-specific, being stimulated by 1 mM GTP; (e) the reaction appears to be specific for microtubule subunits since in the presence of other added proteins and in crude cell extracts, only microtubule subunits aggregate. On the basis of these criteria, we conclude that we have established an in vitro system for the aggregation of microtubule subunits that shares some of the properties characteristic of the in vivo assembly of cytoplasmic and spindle microtubules.

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Section: Resultsmentioning

confidence: 99%

Section: Protocols For Polymerization Experimentsmentioning

confidence: 99%

In Vitro Aggregation of Cytoplasmic Microtubule Subunits

Borisy

Olmsted

Klugman

1972

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

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“…Or, un travail recent dtmontre que l'on peut I inverser l'action biologique de la Colcemide (N-mtthyl N-dtsacttyl colchicine) par irradia-I tion du produit 366 nm. Ce comportement est expliqut par la photodtgradation de la substance (4). Pourtant, d'autres auteurs (5) observent des effets difftrents selon la region spectrale d'irradiation utiliste.…”

Section: Introductionunclassified

Processus photophysiques dans la molécule de colchicine

Roigt¹,

Leblanc²

1973

Can. J. Chem.

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The photophysics of colchicine has been studied by absorption and luminescence spectroscopy. The quantum yield of phosphorescence has been found to be 0.86. The quantum yield measurements of colchicine photodegradation in different solvents are reported. The polarity and hydrogen bond character of the solvents are observed to play an important role in these measurements. The Jablonski diagram is proposed for the colchicine molecule.

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“…This finding is not in conflict with that of Aronso and Inoue [8] because they did their experiments wi eggs undergoing the first divisions, and the sea urchin egg must have a pool of microtubule proteins sufficie for the formation of many mitotic spindles. Even if only l/3 of the proteins survived the irradiation and no synthesis of microtubule protein were occurring, some spindle reformation would still be possible.…”

Section: Discussionmentioning

confidence: 76%