JCB logo
amgmicro.com
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 550K)
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 Zigmond, S. H.
Right arrow Articles by Devreotes, P. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zigmond, S. H.
Right arrow Articles by Devreotes, P. N.
Right arrowPubmed/NCBI databases
*Compound via MeSH
*Substance via MeSH
Hazardous Substances DB
*MAGNESIUM COMPOUNDS
*MAGNESIUM, ELEMENTAL
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, 0021-9525/1997//363 $5.00
The Journal of Cell Biology, Volume 138, Number 2, , 1997 363-374

Article

Regulation of Actin Polymerization in Cell-free Systems by GTP{gamma}S and Cdc42



Sally H. Zigmond*, Michael Joyce*, Jane Borleis§, Gary M. Bokoch{ddagger}, and Peter N. Devreotes§

* Biology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018; {ddagger} Department of Immunology and Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037; and § Department of Biological Chemistry, The Johns Hopkins School of Medicine, Baltimore, Maryland 21205

We have established a cell-free system to investigate pathways that regulate actin polymerization. Addition of GTP{gamma}S to lysates of polymorphonuclear leukocytes (PMNs) or Dictyostelium discoideum amoeba induced formation of filamentous actin. The GTP{gamma}S appeared to act via a small G-protein, since it was active in lysates ofD. discoideum mutants missing either the {alpha}2- or β-subunit of the heterotrimeric G-protein required for chemoattractant-induced actin polymerization in living cells. Furthermore, recombinant Cdc42, but not Rho or Rac, induced polymerization in the cell-free system. The Cdc42-induced increase in filamentous actin required GTP{gamma}S binding and was inhibited by a fragment of the enzyme PAK1 that binds Cdc42.

In a high speed supernatant, GTP{gamma}S alone was ineffective, but GTP{gamma}S-loaded Cdc42 induced actin polymerization, suggesting that the response was limited by guanine nucleotide exchange. Stimulating exchange by chelating magnesium, by adding acidic phospholipids, or by adding the exchange factors Cdc24 or Dbl restored the ability of GTP{gamma}S to induce polymerization. The stimulation of actin polymerization did not correlate with PIP2 synthesis.

Abbreviations used in this paper: F-actin, filamentous actin; G-actin; globular actin; GDI, guanine nucleotide dissociation inhibitory factor; GEF, guanine nucleotide exchange factor; GST, glutathione-S-transferase; HSS, high speed supernatant; LSS, low speed supernatant; PI, phosphatidylinositol; PIP2, phosphatidylinositol bisphosphate; PMN, polymorphonuclear leukocytes.

National Institues of Health grants AI19883 to S.H. Zigmond; GM44428 to G.M. Bokoch; and GM28007 to P.N. Devreotes.

Please address all correspondence to Sally Zigmond, Biology Department, University of Pennsylvania, Philadelphia, PA 19104-6018. Tel.: (215) 898-4559; Fax: (215) 898-8780.


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