dictyNews Volume 28 Number 04

Published in

· 1 year ago

dictyNews 
Electronic Edition 
Volume 28, number 4 
February 9, 2007 

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

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

 

A stress response kinase, KrsA, controls cAMP relay during the early  
development of Dictyostelium discoideum 

Tetsuya Muramoto#, Hidekazu Kuwayama#, Kumiko Kobayashi, 
and Hideko Urushihara 
# These two authors are equally contributed. 

 
Developmental Biology, in press 

Solitary amoebae of Dictyostelium discoideum are frequently exposed to  
stressful conditions in nature, and their multicellular development is  
one response to environmental stress. Here we analyzed an aggregation  
stage abundant gene, krsA, homologous to human krs1 (kinase responsive to  
stress 1) to understand the mechanisms for the initiation of development  
and cell fate determination. The krsA- cells exhibited reduced viability  
under hyperosmotic conditions. They produced smaller aggregates on membrane  
filters and did not form aggregation streams on a plastic surface under  
submerged starvation conditions, but were normal in sexual development.  
During early asexual development, the expression of cAMP-related genes  
peaked earlier in the knockout mutants. Neither cAMP oscillation in starved  
cells nor an increase in the cAMP level following osmotic stress was  
observed in krsA-. The nuclear export signal, as well as the kinase domain,  
in KrsA was necessary for stream formation. These results strongly suggest  
that krsA is involved in cAMP relay, and that signaling pathways for  
multicellular development have evolved in unison with the stress response.  

 
Submitted by Hideko Urushihara [hideko@biol.tsukuba.ac.jp] 
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[End dictyNews, volume 28, number 4]