Influx of extracellular Ca2+ is necessary for electrotaxis in Dictyostelium

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

Research output: Contribution to journalArticle

38 Scopus citations

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 45Ca2+ 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, ip1A-null Distyostelium cells showed the same electrotactic response as wild-type cells. Therefore, ipslA-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 Distyostelium 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 (US)
Pages (from-to)4741-4748
Number of pages8
JournalJournal of Cell Science
Volume119
Issue number22
DOIs
StatePublished - Nov 15 2006
Externally publishedYes

Keywords

  • Calcium
  • Cell migration
  • Dictyostelium
  • Electrotaxis
  • IplA

ASJC Scopus subject areas

  • Cell Biology

Fingerprint Dive into the research topics of 'Influx of extracellular Ca<sup>2+</sup> is necessary for electrotaxis in Dictyostelium'. Together they form a unique fingerprint.

  • Cite this