Dictyostelium chemotaxis: essential Ras activation and accessory signalling pathways for amplification


Kortholt A., Kataria R., Keizer-Gunnink I., Van Egmond W. N. , Khanna A., Van Haastert P. J. M.

EMBO REPORTS, vol.12, no.12, pp.1273-1279, 2011 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 12 Issue: 12
  • Publication Date: 2011
  • Doi Number: 10.1038/embor.2011.210
  • Journal Name: EMBO REPORTS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1273-1279
  • Keywords: chemotaxis, shallow gradients, Ras, amplification, synergy, CHEMOATTRACTANT GRADIENTS, MEDIATES CHEMOTAXIS, LIVING CELLS, DISCOIDEUM, PROTEIN, RECEPTORS, ORIENTATION, PI3-KINASE, MOTILITY, PARALLEL

Abstract

Central to chemotaxis is the molecular mechanism by which cells exhibit directed movement in shallow gradients of a chemoattractant. We used Dictyostelium mutants to investigate the minimal requirements for chemotaxis, and identified a basal signalling module providing activation of Ras at the leading edge, which is sufficient for chemotaxis. The signalling enzymes PI3K, TorC2, PLA2 and sGC are not required for Ras activation and chemotaxis to folate or to steep gradients of cAMP, but they provide a memory of direction and improved orientation of the cell, which together increase the sensitivity about 150-fold for chemotaxis in shallow cAMP gradients.