JCB logo
MBoC5 from Garland Science
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article
Right arrow Full Text
Right arrow PDF (Full Text)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fagotto, F.
Right arrow Articles by Costantini, F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fagotto, F.
Right arrow Articles by Costantini, F.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

J. Cell Biol., Volume 145, Number 4, May 17, 1999 741-756

Domains of Axin Involved in Protein-Protein Interactions, Wnt Pathway Inhibition, and Intracellular Localization

François Fagotto,* Eek-hoon Jho,Dagger Li Zeng,Dagger Thomas Kurth,* Thomas Joos,* Christine Kaufmann,* and Frank CostantiniDagger

* Division of Cell Biology, Max-Planck Institute for Developmental Biology, 72076 Tübingen, Germany; and Dagger  Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York 10032

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.

Key words: beta -catenin;  glycogen synthase kinase 3beta (GSK3beta );  adenomatous polyposis coli (APC);  Dishevelled (Dsh);  dorsal axis formation


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents