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Relationship: 714


A descriptive phrase which clearly defines the two KEs being considered and the sequential relationship between them (i.e., which is upstream, and which is downstream). More help

Binding, Tubulin leads to Disruption, Microtubule dynamics

Upstream event
The causing Key Event (KE) in a Key Event Relationship (KER). More help
Downstream event
The responding Key Event (KE) in a Key Event Relationship (KER). More help

Key Event Relationship Overview

The utility of AOPs for regulatory application is defined, to a large extent, by the confidence and precision with which they facilitate extrapolation of data measured at low levels of biological organisation to predicted outcomes at higher levels of organisation and the extent to which they can link biological effect measurements to their specific causes.Within the AOP framework, the predictive relationships that facilitate extrapolation are represented by the KERs. Consequently, the overall WoE for an AOP is a reflection in part, of the level of confidence in the underlying series of KERs it encompasses. Therefore, describing the KERs in an AOP involves assembling and organising the types of information and evidence that defines the scientific basis for inferring the probable change in, or state of, a downstream KE from the known or measured state of an upstream KE. More help

AOPs Referencing Relationship

AOP Name Adjacency Weight of Evidence Quantitative Understanding Point of Contact Author Status OECD Status
Chemical binding to tubulin in oocytes leading to aneuploid offspring adjacent High Francesco Marchetti (send email) Open for citation & comment EAGMST Under Review

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KER.In general, this will be dictated by the more restrictive of the two KEs being linked together by the KER.  More help
Term Scientific Term Evidence Link
Homo sapiens Homo sapiens Moderate NCBI
mouse Mus musculus High NCBI
Xenopus laevis Xenopus laevis Low NCBI

Sex Applicability

An indication of the the relevant sex for this KER. More help
Sex Evidence
Mixed High

Life Stage Applicability

An indication of the the relevant life stage(s) for this KER.  More help
Term Evidence
All life stages High

Key Event Relationship Description

Provides a concise overview of the information given below as well as addressing details that aren’t inherent in the description of the KEs themselves. More help

Chemicals that bind to tubulin on colchicine or vinca domain directly interfere with the addition of new tubulin dimers to the microtubules. The result of this process is a net loss of microtubules (i.e., microtubule depolymerization).

Evidence Collection Strategy

Include a description of the approach for identification and assembly of the evidence base for the KER. For evidence identification, include, for example, a description of the sources and dates of information consulted including expert knowledge, databases searched and associated search terms/strings.  Include also a description of study screening criteria and methodology, study quality assessment considerations, the data extraction strategy and links to any repositories/databases of relevant references.Tabular summaries and links to relevant supporting documentation are encouraged, wherever possible. More help

Evidence Supporting this KER

Addresses the scientific evidence supporting KERs in an AOP setting the stage for overall assessment of the AOP. More help

Strong based on biological plausibility and available empirical data. There is no uncertainty.

Biological Plausibility
Addresses the biological rationale for a connection between KEupstream and KEdownstream.  This field can also incorporate additional mechanistic details that help inform the relationship between KEs, this is useful when it is not practical/pragmatic to represent these details as separate KEs due to the difficulty or relative infrequency with which it is likely to be measured.   More help

The weight of evidence for this KER is strong. The majority of work for this KER has been derived from research on the prototypical chemical colchicine; however, information is also available for other chemicals such as podophillotoxin, vinblastin, and colcemid. There is high biological plausibility for the binding of colchicine to tubulin leading to microtubule depolymerization, which is one of the most studied chemical interactions with a biological molecule [Margolis and Wilson, 1977; Garland, 1978; Ravelli et al., 2004]. There is extensive understanding of the chemistry of both the binding interactions and the subsequent interference with microtubule dynamics. Depolymerization following colchicine exposure has been measured in frog and mouse eggs, and in human cells, including eggs, in culture [Salmon et al., 1984; Wilson et al., 1984; Ibanez et al., 2003; Liu et al., 2010].

Uncertainties and Inconsistencies
Addresses inconsistencies or uncertainties in the relationship including the identification of experimental details that may explain apparent deviations from the expected patterns of concordance. More help

No apparent uncertainties or inconsistencies. This KER is biologically plausible and broadly accepted. Indeed, in vitro assays to measure tubulin depolymerization are well standardized and represent the gold standard to determine whether a chemical is binding to tubulin.

Known modulating factors

This table captures specific information on the MF, its properties, how it affects the KER and respective references.1.) What is the modulating factor? Name the factor for which solid evidence exists that it influences this KER. Examples: age, sex, genotype, diet 2.) Details of this modulating factor. Specify which features of this MF are relevant for this KER. Examples: a specific age range or a specific biological age (defined by...); a specific gene mutation or variant, a specific nutrient (deficit or surplus); a sex-specific homone; a certain threshold value (e.g. serum levels of a chemical above...) 3.) Description of how this modulating factor affects this KER. Describe the provable modification of the KER (also quantitatively, if known). Examples: increase or decrease of the magnitude of effect (by a factor of...); change of the time-course of the effect (onset delay by...); alteration of the probability of the effect; increase or decrease of the sensitivity of the downstream effect (by a factor of...) 4.) Provision of supporting scientific evidence for an effect of this MF on this KER. Give a list of references.  More help

Microtubules assembled in vitro contain several minor protein components that have been referred to as microtubule-associated proteins (MAPs). Several of these proteins are believed to play a role in the microtubule assembly process [Kakiu & Sato, 2016]. MAPs have been shown to inhibit colchicine binding to tubulin in a competitive manner. In contrast, Mg2+, which also induces microtubule assembly in vitro, had no effect on colchicine binding to tubulin [Nunez J et al. 1978].

Response-response Relationship
Provides sources of data that define the response-response relationships between the KEs.  More help

Microtubule assembly is inhibited by approximately 50% when half of the tubulin dimers are bound by colchicine [Margolis et al., 1980], and a concentration of 2.5 μM of colchicine is needed to inhibit microtubule polymerization by 50% [Zavala et al., 1980].  

Information regarding the approximate time-scale of the changes in KEdownstream relative to changes in KEupstream (i.e., do effects on KEdownstream lag those on KEupstream by seconds, minutes, hours, or days?). More help

Colchicine binds slowly to tubulin, in contrast to Combretastatin A4, which binds in a relatively fast, temperature-dependent manner. The rate of Colchicine binding has a rate constant of ~102 M-1 s-1 as determined by an isotopic labeling technique [Gaarland D.L. 1978]. Hovever, colchicine dissociates from tubulin over 100 times slower than combretastatin A-4, with a of 405 min at 37 °C, compared to 3.6 min of CA4 [Lin et al. 1989].

Known Feedforward/Feedback loops influencing this KER
Define whether there are known positive or negative feedback mechanisms involved and what is understood about their time-course and homeostatic limits. More help

To our knowledge, there are no feedback loops influencing this KER. 

Domain of Applicability

A free-text section of the KER description that the developers can use to explain their rationale for the taxonomic, life stage, or sex applicability structured terms. More help

This KER has been demonstrated in multiple species including sea urchins, frogs, mice, rats, cows, and human cells in culture.


List of the literature that was cited for this KER description. More help

Bhattacharyya B, Panda D, Gupta S, Banerjee M. 2008. Anti-mitotic activity of colchicine and the structural basis for its interaction with tubulin. Med Res Rev 28:155-183.

Brunner M, Albertini S, Würgler FE. 1991. Effects of 10 known or suspected spindle poisons in the in vitro porcine brain tubulin assembly assay. Mutagen 6:65-70.

Garland DL. 1978. Kinetics and mechanism of colchicine binding to tubulin: Evidence for ligand-induced conformational change. Biochemistry 17:4266–4272.

Hastie SB. 1991. Interaction of colchicine with tubulin. Pharmacol Ther 51:377-401.

Kakui Y, Sato M. 2016. Differentiating the roles of microtubule-associated proteins at meiotic kinetochores during chromosome segregation. Chromosoma 125:309-320.

Ibanez E, Albertini DF, Overstrom EW. 2003. Demecolcine-induced oocyte enucleation for somatic cell cloning: Coordination between cell-cycle egress, kinetics of cortical cytoskeletal interactions, and second polar body extrusion. Biol Reprod 68:1249–1258.

Linn CM, Ho HH, Pettit GR, Hamel E. 1989. Antimitotic natural products combretastatin A-4 ad combretastatin A: studies on the mechanism of their inhibition of the binding of colchicine to tubulin. Biochemistry 28:6984-6991.

Liu S, Li Y, Feng HL, Yan JH, Li M, Ma SY, Chen ZJ. 2010. Dynamic modulation of cytoskeleton during in vitro maturation in human oocytes. Am J Obstet Gynecol 203:151.e151–157.

Nunez J, Fellous A, Francon J, Lennon AN. 1978. Competitive inhibition of colchicine binding to tubulin by microtubule-associated proteins. Proc Natl Acad Sci USA 76:86-90.

Margolis RL, Wilson L. 1977. Addition of colchicine-tubulin complex to microtubule ends: the mechanism of substoichiometric colchicine poisoning. Proc Natl Acad Sci U S A 74:3466-3470.

Margolis RL, Rauch CT, Wilson L. 1980. Mechanism of colchicine-dimer addition to microtubule polymerization mechanism. Biochemistry 19:5550-5557.

Pettit GR, Toki B, Herald DL, Verdier-Pinard P, Boyd MR, Hamel E, Pettit RK. 1998. Antineoplastic agents. 379. Synthesis of phenstatin phosphate. J Med Chem 41:1688-1695.

Ravelli RB, Gigant B, Curmi PA, Jourdain I, Lachkar S, Sobel A, Knossow M. 2004. Insight into tubulin regulation from a complex with colchicine and a stathmin-like domain. Nature 428:198–202.

Salmon ED, McKeel M, Hays T. 1984. Rapid rate of tubulin dissociation from microtubules in the mitotic spindle in vivo measured by blocking polymerization with colchicine. J Cell Biol 99:1066–1075.

Wallin M, Hartley-Asp B. 1993. Effects of potential aneuploidy inducing agents on microtubule assembly in vitro. Mutat Res 287:17-22.

Wilson L, Miller HP, Pfeffer TA, Sullivan KF, Detrich HW,3. 1984. Colchicine-binding activity distinguishes sea urchin egg and outer doublet tubulins. J Cell Biol 99:37–41