JCB logo
CrossRef
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

Published online 7 August 2000. doi:10.1083/jcb.150.3.527
This Article
Right arrow Full Text
Right arrow PDF (Full Text)
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 Skoble, J.
Right arrow Articles by Welch, M. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Skoble, J.
Right arrow Articles by Welch, M. D.
Right arrowPubmed/NCBI databases
*Substance via MeSH
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?
© The Rockefeller University Press, 0021-9525/2000/8/527/ $5.00
The Journal of Cell Biology, Volume 150, Number 3, August 7, 2000 527-538


Original Article

Three Regions within ActA Promote Arp2/3 Complex-mediated Actin Nucleation and Listeria monocytogenes Motility

Justin Skoblea, Daniel A. Portnoya,b, and Matthew D. Welcha
a Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720-3200
b School of Public Health, University of California, Berkeley, Berkeley, California 94720-3200

Correspondence to: Matthew D. Welch, Department of Molecular and Cell Biology, LSA Room 301, University of California, Berkeley, Berkeley, CA 94720-3200. Tel:(510) 643-9019 Fax:(510) 643-6791 E-mail:welch{at}socrates.berkeley.edu.

The Listeria monocytogenes ActA protein induces actin-based motility by enhancing the actin nucleating activity of the host Arp2/3 complex. Using systematic truncation analysis, we identified a 136-residue NH2-terminal fragment that was fully active in stimulating nucleation in vitro. Further deletion analysis demonstrated that this fragment contains three regions, which are important for nucleation and share functional and/or limited sequence similarity with host WASP family proteins: an acidic stretch, an actin monomer–binding region, and a cofilin homology sequence. To determine the contribution of each region to actin-based motility, we compared the biochemical activities of ActA derivatives with the phenotypes of corresponding mutant bacteria in cells. The acidic stretch functions to increase the efficiency of actin nucleation, the rate and frequency of motility, and the effectiveness of cell–cell spread. The monomer-binding region is required for actin nucleation in vitro, but not for actin polymerization or motility in infected cells, suggesting that redundant mechanisms may exist to recruit monomer in host cytosol. The cofilin homology sequence is critical for stimulating actin nucleation with the Arp2/3 complex in vitro, and is essential for actin polymerization and motility in cells. These data demonstrate that each region contributes to actin-based motility, and that the cofilin homology sequence plays a principal role in activation of the Arp2/3 complex, and is an essential determinant of L. monocytogenes pathogenesis.

Key Words: bacteria, pathogenesis, cell movement, cytoskeleton, microfilament proteins


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