JCB logo
MBL International Tel: 800.200.5459 CLICK HERE
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published 15 October 2001. doi:10.1083/jcb.200106157
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 203K)
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 Palmgren, S.
Right arrow Articles by Lappalainen, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Palmgren, S.
Right arrow Articles by Lappalainen, P.
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, 0021-9525/2001/10/251 $5.00
The Journal of Cell Biology, Volume 155, Number 2, October 15, 2001 251-260

Article

Interactions with PIP2, ADP-actin monomers, and capping protein regulate the activity and localization of yeast twinfilin



Sandra Palmgren1, Pauli J. Ojala1, Martin A. Wear2, John A. Cooper2 and Pekka Lappalainen1

1 Program in Cellular Biotechnology, Institute of Biotechnology, FIN-00014 University of Helsinki, Helsinki, Finland
2 Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110

Address correspondence to Pekka Lappalainen, Institute of Biotechnology, P.O. Box 56 (Viikinkaari 9), FIN-00014 University of Helsinki, Helsinki, Finland. Tel.: 358-9-1915-9499. Fax: 358-9-1915-9366. E-mail: pekka.lappalainen{at}helsinki.fi

Twinfilin is a ubiquitous actin monomer–binding protein that regulates actin filament turnover in yeast and mammalian cells. To elucidate the mechanism by which twinfilin contributes to actin filament dynamics, we carried out an analysis of yeast twinfilin, and we show here that twinfilin is an abundant protein that localizes to cortical actin patches in wild-type yeast cells. Native gel assays demonstrate that twinfilin binds ADP-actin monomers with higher affinity than ATP-actin monomers. A mutant twinfilin that does not interact with actin monomers in vitro no longer localizes to cortical actin patches when expressed in yeast, suggesting that the ability to interact with actin monomers may be essential for the localization of twinfilin. The localization of twinfilin to the cortical actin cytoskeleton is also disrupted in yeast strains where either the CAP1 or CAP2 gene, encoding for the {alpha} and ß subunits of capping protein, is deleted. Purified twinfilin and capping protein form a complex on native gels. Twinfilin also interacts with phosphatidylinositol 4,5-bisphosphate (PI[4,5]P2), and its actin monomer–sequestering activity is inhibited by PI(4,5)P2. Based on these results, we propose a model for the biological role of twinfilin as a protein that localizes actin monomers to the sites of rapid filament assembly in cells.

Key Words: actin; twinfilin; capping protein; PI(4,5)P2; budding yeast


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 has been cited by other articles:



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