Domains of axin involved in protein-protein interactions, Wnt pathway inhibition, and intracellular localization

Research output: Contribution to journalResearch articleContributedpeer-review


  • F. Fagotto - , Max Planck Institute for Developmental Biology (Author)
  • E.H. Jho - (Author)
  • L. Zeng - , Columbia University, Max Planck Institute for Developmental Biology (Author)
  • Thomas Kurth - , Max Planck Institute for Developmental Biology, Columbia University (Author)
  • T. Joos - (Author)
  • C. Kaufmann - (Author)
  • F. Costantini - (Author)


Axin was identified as a regulator of embryonic axis induction in vertebrates that inhibits the Wnt signal transduction pathway. Epistasis experiments in frog embryos indicated that Axin functioned downstream of glycogen synthase kinase 3beta (GSK3beta) and upstream of beta-catenin, and subsequent studies showed that Axin is part of a complex including these two proteins and adenomatous polyposis coli (APC). Here, we examine the role of different Axin domains in the effects on axis formation and beta-catenin levels. We find that the regulators of G-protein signaling domain (major APC-binding site) and GSK3beta-binding site are required, whereas the COOH-terminal sequences, including a protein phosphatase 2A binding site and the DIX domain, are not essential. Some forms of Axin lacking the beta-catenin binding site can still interact indirectly with beta-catenin and regulate beta-catenin levels and axis formation. Thus in normal embryonic cells, interaction with APC and GSK3beta is critical for the ability of Axin to regulate signaling via beta-catenin. Myc-tagged Axin is localized in a characteristic pattern of intracellular spots as well as at the plasma membrane. NH2-terminal sequences were required for targeting to either of these sites, whereas COOH-terminal sequences increased localization at the spots. Coexpression of hemagglutinin-tagged Dishevelled (Dsh) revealed strong colocalization with Axin, suggesting that Dsh can interact with the Axin/APC/GSK3/beta-catenin complex, and may thus modulate its activity.


Original languageEnglish
Pages (from-to)741-756
Number of pages16
JournalThe Journal of cell biology
Issue number4
Publication statusPublished - 17 May 1999
Externally publishedYes

External IDs

PubMedCentral PMC2133179
Scopus 0033577808
ORCID /0000-0001-5624-1717/work/142239042



  • Adaptor Proteins, Signal Transducing, Adenomatous Polyposis Coli Protein, Animals, Axin Protein, Calcium-Calmodulin-Dependent Protein Kinases/metabolism, Cell Line, Cytoskeletal Proteins/metabolism, Dishevelled Proteins, Glycogen Synthase Kinase 3, Glycogen Synthase Kinases, Humans, Intracellular Fluid/metabolism, Mutagenesis, Neoplasm Proteins/metabolism, Phosphoproteins/metabolism, Phosphorylation, Proteins/chemistry, Proto-Oncogene Proteins/metabolism, Repressor Proteins, Structure-Activity Relationship, Trans-Activators, Wnt Proteins, Xenopus/embryology, Xenopus Proteins, Zebrafish Proteins, beta Catenin

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