dictyNews Volume 33 Number 11

Published in

· 10 months ago

dictyNews 
Electronic Edition 
Volume 33, number 11 
October 30, 2009 

Please submit abstracts of your papers as soon as they have been 
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http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit. 

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========= 
Abstracts 
========= 

 
Propagating waves separate two states of actin organization in living cells 

Britta Schroth-Diez,1 Silke Gerwig,1 Mary Ecke,2 Reiner Hegerl,2 
Stefan Diez,1 and Günther Gerisch2 

1Max-Planck-Institut für Molekulare Zellbiologie und Genetik,  
Pfotenhauerstrasse 108, D-01307 Dresden, Germany 
2Max-Planck-Institut für Biochemie, Am Klopferspitz 18,  
D-82152 Martinsried, Germany 

 
HFSP Journal, in press [DOI: 10.2976/1.3239407] 

Propagating actin waves are dynamic supramolecular structures formed by the  
self-assembly of proteins within living cells. They are built from actin filaments  
together with single-headed myosin, the Arp2/3 complex, and coronin in a  
defined three-dimensional order. The function of these waves in structuring the  
cell cortex is studied on the substrate-attached surface of Dictyostelium cells  
by the use of total internal reflection fluorescence (TIRF) microscopy. Actin  
waves separate two areas of the cell cortex from each other, which are  
distinguished by the arrangement of actin filaments. The Arp2/3 complex  
dominates in the area enclosed by a wave, where it has the capacity of  
building dendritic structures, while the proteins prevailing in the external area,  
cortexillin I and myosin-II, bundle actin filaments and arrange them in  
antiparallel direction. Wave propagation is accompanied by transitions in the  
state of actin with a preferential period of 5 min. Wave generation is preceded  
by local fluctuations in actin assembly, some of the nuclei of polymerized actin  
emanating from clathrin-coated structures, others emerging independently.  
The dynamics of phase transitions has been analyzed to provide a basis for  
modeling the nonlinear interactions that produce spatio-temporal patterns in  
the actin system of living cells.  

Submitted by Günther Gerisch [gerisch@biochem.mpg.de] 
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[End dictyNews, volume 33, number 11]