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

This Article Full Text (PDF, 469K) Alert me when this article is cited Services Email this article Similar articles in this journal Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Tuma, R. Search for Related Content PubMed Articles by Tuma, R. Related Collections Related Article Social Bookmarking                            What's this?

One protein, two pools

The cytoplasmic protein ß-catenin is essential for both intercellular adhesion and intracellular Wnt signaling. Invertebrates have multiple genes to cover the multiple functions, but on page 339 Gottardi and Gumbiner propose that vertebrate cells make do with one gene by maintaining different pools of protein for the different roles. Different folding may distinguish the adhesion and proliferative signaling functions.

Cofractionation experiments showed that ß-catenin that interacts with cadherin is in a heterodimer with -catenin, but Wnt signaling induces a monomeric form of ß-catenin that interacts with a transcription factor complex. After enriching for cadherins, ß-catenin can be detected using antibodies to either NH₂-terminal or COOH-terminal regions; but in the cadherin-free fraction only the NH₂-terminal antibody binds. The team hypothesizes that the ß-catenin protein is folded back on itself in its monomeric form and, as such, is available for transcription complex binding but not for adhesion duties.

Gottardi speculates that a post-translational modification is responsible for the conformational change but does not yet know what that modification is. Furthermore, she thinks this sort of molecular segregation may be a common mechanism cells use to allow one protein to do multiple jobs, without the more common function soaking up all the protein required for a temporally regulated one.

Rabiya Tuma

rabiya{at}nasw.org

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

Related Article

Distinct molecular forms of ß-catenin are targeted to adhesive or transcriptional complexes

Cara J. Gottardi and Barry M. Gumbiner
J. Cell Biol. 2004 167: 339-349. [Abstract] [Full Text] [PDF]

This Article Full Text (PDF, 469K) Alert me when this article is cited Services Email this article Similar articles in this journal Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Tuma, R. Search for Related Content PubMed Articles by Tuma, R. Related Collections Related Article Social Bookmarking                            What's this?