Influx of extracellular Ca2+ is necessary for electrotaxis in Dictyostelium

Shanley, Lynne J., Walczysko, Petr, Bain, Mary, MacEwan, David J. and Zhao, Min (2006) Influx of extracellular Ca2+ is necessary for electrotaxis in Dictyostelium. Journal of Cell Science, 119 (22). pp. 4741-4748. ISSN 0021-9533

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Intracellular free Ca2+ ([Ca2+](i)) is a pivotal signalling element in cell migration and is thought to be required for chemotaxis of Dictyostelium. Ca2+ signalling may also be important for electrotaxis. However this suggestion has been controversial. We show that electric fields direct Dictyostelium cells to migrate cathodally and increase [Ca2+] i in Dictyostelium cells, as determined by Fluo-3 AM imaging and Ca-45(2+) uptake. Omission of extracellular Ca2+([Ca2+](e)) and incubation with EGTA abolished the electric-field-stimulated [Ca2+](i) rise and directional cell migration. This suggests a requirement for [Ca2+](e) in the electrotactic response. Deletion of iplA, a gene responsible for chemoattractant-induced [ Ca2+](i) increase, had only a minor effect on the electric-field-induced [Ca2+](i) rise. Moreover, iplA-null Dictyostelium cells showed the same electrotactic response as wild-type cells. Therefore, iplA-independent Ca2+ influx is necessary for electrotactic cell migration. These results suggest that the [ Ca2+](i) regulatory mechanisms induced by electric fields are different from those induced by cAMP and folic acid in Dictyostelium cells. Different roles of the iplA gene in chemoattractant-induced and electrically induced Ca2+ signalling, and different effects of [ Ca2+](i) elevation on chemotaxis and electrotaxis indicate that the chemoattractant and electric cues activate distinctive initial signalling elements.

Item Type: Article
Uncontrolled Keywords: calcium,cell migration,dictyostelium,ipla,electrotaxis
Faculty \ School: Faculty of Science > School of Pharmacy
Depositing User: Rachel Smith
Date Deposited: 23 May 2011 09:44
Last Modified: 24 Oct 2022 02:01
DOI: 10.1242/jcs.03248

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