JCB logo
amgmicro.com
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published 18 February 2002. doi:10.1083/jcb1564rr2
This Article
Right arrow Full Text (PDF, 169K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by LeBrasseur, N.
Right arrow Search for Related Content
PubMed
Right arrow Articles by LeBrasseur, N.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/2002/2/588-a $5.00
The Journal of Cell Biology, Volume 156, Number 4, February 18, 2002 588-a-588

Research Roundup

Structural Mad-ness


Binding of MBP1 (red) causes a rearrangement (yellow) in Mad2.

Yu/Elsevier

The spindle checkpoint is turned on when unattached kinetochores generate a signal that inhibits the anaphase-promoting complex (APC) preventing premature chromosome separation. Now, Hongtao Yu and colleagues (University of Texas Southwestern Medical Center, Dallas, TX) have shown that conformational changes in the protein Mad2 are important in triggering this checkpoint pathway.

Monomeric Mad2 is recruited to the kinetochore when it forms a complex with Mad1. Mad2 can also associate with Cdc20, an APC activator, thereby inhibiting Cdc20 and the APC.

Mad2 is constitutively present in the cell, but does not always inhibit Cdc20. Yu set out to determine the basis of inhibition by analyzing the structure of bound and unbound Mad2. NMR structures of free Mad2 and Mad2 bound to a Mad2-binding peptide (MBP1) revealed a striking shift in the conformation of the protein upon peptide binding. A single ß strand and the COOH terminus of the protein translocated from one end of the main ß sheet to the other.

Binding of either Mad1 or Cdc20 caused similar conformational shifts in Mad2. According to Yu, the results suggest that Mad1 binding to Mad2 might help convert the protein to a form more compatible for binding to Cdc20, and that protein complexes containing Mad2 and Cdc20 may spread through the cell, dispersing the checkpoint signal. Yu would now like to identify how Mad2 changes its binding partner from Mad1 to Cdc20, especially given the fact that the two bind Mad2 with similar affinities. {blacksquare}

Reference:

Luo, X., et al. 2002. Mol. Cell. 9:59–71.[CrossRef][Medline]

labrasn{at}rockefeller.edu



Nicole LeBrasseur


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 Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



This Article
Right arrow Full Text (PDF, 169K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by LeBrasseur, N.
Right arrow Search for Related Content
PubMed
Right arrow Articles by LeBrasseur, N.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

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