G protein signaling events are activated at the leading edge of chemotactic cells

Cell. 1998 Oct 2;95(1):81-91. doi: 10.1016/s0092-8674(00)81784-5.


Directional sensing by eukaryotic cells does not require polarization of chemoattractant receptors. The translocation of the PH domain-containing protein CRAC in D. discoideum to binding sites on the inner face of the plasma membrane reflects activation of the G protein-linked signaling system. Increments in chemoattractant elicit a uniform response around the cell periphery. Yet when cells are exposed to a gradient, the activation occurs selectively at the stimulated edge, even in immobilized cells. We propose that such localized activation, transmitted by the recruitment of cytosolic proteins, may be a general mechanism for gradient sensing by G protein-linked chemotactic systems including those involving chemotactic cytokines in leukocytes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Biological Transport
  • Cell Fractionation
  • Cell Membrane / metabolism
  • Chemotactic Factors / pharmacology
  • Chemotaxis*
  • Cyclic AMP / pharmacology
  • Cytosol / metabolism
  • Dictyostelium
  • GTP-Binding Proteins / metabolism*
  • Green Fluorescent Proteins
  • Hydrogen-Ion Concentration
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism*
  • Signal Transduction*


  • Chemotactic Factors
  • Luminescent Proteins
  • Protozoan Proteins
  • dagA protein, Dictyostelium
  • Green Fluorescent Proteins
  • Cyclic AMP
  • GTP-Binding Proteins