Tankyrase inhibitors stimulate the ability of tankyrases to bind axin and drive assembly of β-catenin degradation-competent axin puncta

Estefania Martino-Echarri, Mariana G. Brocardo, Kate M. Mills, Beric R. Henderson

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)
26 Downloads (Pure)


Activation of the wnt signaling pathway is a major cause of colon cancer development. Tankyrase inhibitors (TNKSi) have recently been developed to block the wnt pathway by increasing axin levels to promote degradation of the wnt-regulator β-catenin. TNKSi bind to the PARP (poly(ADP)ribose polymerase) catalytic region of tankyrases (TNKS), preventing the PARylation of TNKS and axin that normally control axin levels through ubiquitination and degradation. TNKSi treatment of APC-mutant SW480 colorectal cancer cells can induce axin puncta which act as sites for assembly of β-catenin degradation complexes, however this process is poorly understood. Using this model system, we found that siRNA knockdown of TNKSs 1 and 2 actually blocked the ability of TNKSi drugs to induce axin puncta, revealing that puncta formation requires both the expression and the inactivation of TNKS. Immunoprecipitation assays showed that treatment of cells with TNKSi caused a strong increase in the formation of axin-TNKS complexes, correlating with an increase in insoluble or aggregated forms of TNKS/axin. The efficacy of TNKSi was antagonized by proteasome inhibitors, which stabilized the PARylated form of TNKS1 and reduced TNKSimediated assembly of axin-TNKS complexes and puncta. We hypothesise that TNKSi act to stimulate TNKS oligomerization and assembly of the TNKS-axin scaffold that form puncta. These new insights may help in optimising the future application of TNKSi in anticancer drug design.

Original languageEnglish
Article numbere0150484
Pages (from-to)1-19
Number of pages19
JournalPLoS ONE
Issue number3
Publication statusPublished - 1 Mar 2016
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2016. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


Dive into the research topics of 'Tankyrase inhibitors stimulate the ability of tankyrases to bind axin and drive assembly of β-catenin degradation-competent axin puncta'. Together they form a unique fingerprint.

Cite this