dictyNews Volume 22 Number 07

Published in

· 10 months ago

Dicty News 
Electronic Edition 
Volume 22, number 7 
March 26, 2004 

Please submit abstracts of your papers as soon as they have been 
accepted for publication by sending them to dicty@northwestern.edu 
or by using the form at 
http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit. 

Back issues of Dicty-News, the Dicty Reference database and other  
useful information is available at dictyBase - http://dictybase.org. 

 
 
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  Abstracts 
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The identification of Dictyostelium phosphoproteins altered in response to  
the activation of RasG 

David M. Secko(1), Robert H. Insall(2), George B. Spiegelman(1) and  
Gerry Weeks(1) 

>From the (1)Department of Microbiology and Immunology, University of  
British Columbia, 300-6174 University Blvd., Vancouver, British Columbia,  
V6T 1Z3, Canada and the (2)School of Biosciences, University of Birmingham,  
Birmingham, B15 2TT, U.K. 

Proteomics, in press 

Dictyostelium RasG has been implicated in the regulation of a variety of  
cellular processes, including the initiation of development, cell movement,  
and cytokinesis, but the molecular components of the signaling pathways  
involved are largely unknown. We used a tetracycline-regulated protein  
expression system to study the effect of activated RasG, RasG(G12T),  
expression on the phosphorylation state of Dictyostelium proteins. Over 70  
vegetative phosphoprotein components were resolved by 2D immunoblot analysis  
and of these 16 phosphothreonine and 3 phosphotyrosine protein components  
were found to reproducibly change upon RasG(G12T) expression. Thirteen of  
these were recovered from 2D gels and identified by mass spectrometry of  
in-gel tryptic digestions. The proteins identified include the signaling  
proteins RasGEF-R and PKB, the adhesion protein DdCAD-1, the cytoskeletal  
protein actin, the mitochondrial division protein FtsZA, and proteins  
involved in translation and metabolism. In addition to the direct  
demonstration of the phosphorylation of putative downstream targets of 
 RasG activation, these findings reveal previously undetected  
phosphorylation of several proteins.  

Submitted by: David Secko [dmsecko@interchange.ubc.ca] 

 
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[End Dicty News, volume 22, number 7]