Influx of extracellular Ca2+ is necessary for electrotaxis in Dictyostelium

Lynne Shanley, Petr Walczysko, Mary Bain, David J. MacEwan, Min Zhao

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38 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)4741-4748
Number of pages8
JournalJournal of Cell Science
Volume119
Early online date31 Oct 2006
DOIs
Publication statusPublished - 15 Nov 2006

Keywords

  • calcium
  • cell migration
  • Dictyostelium
  • iplA
  • electrotaxis
  • corneal epithelial cells
  • current electric fields
  • free calcium
  • human keratinocytes
  • directional migration
  • genetic analysis
  • shape changes
  • nerv growth
  • chemotaxis
  • discoideum

Cite this

Shanley, L., Walczysko, P., Bain, M., MacEwan, D. J., & Zhao, M. (2006). Influx of extracellular Ca2+ is necessary for electrotaxis in Dictyostelium. Journal of Cell Science, 119, 4741-4748. https://doi.org/10.1242/jcs.03248