A cell-density sensing factor regulates the lifetime of a chemoattractant-induced G alpha-GTP conformation. | Academic Article individual record

Starving Dictyostelium discoideum cells monitor the local density of other starving cells by simultaneously secreting and sensing CMF. CMF regulates signal transduction through the chemoattractant cAMP receptor, cAR1. cAR1 activates a heterotrimeric G protein by stimulating G alpha 2 to release GDP and bind GTP. We show here that the rate of cAMP-stimulated GTP hydrolysis in membranes from cells exposed to CMF is roughly 4 times slower than in membranes from untreated cells, even though the rate of GTP binding is the same. This hydrolysis is abolished in cells lacking G alpha 2. Our data thus suggest that CMF regulates cAMP signal transduction in part by prolonging the lifetime of the G alpha 2-GTP complex.

author list (cited authors)
Brazill, D. T., Gundersen, R., & Gomer, R. H.
publication date
Wiley Publisher
published in
FEBS Letters Journal
  • Protozoan Proteins
  • Signal Transduction
  • Guanosine Triphosphate
  • Cell Adhesion Molecules
  • Dictyostelium
  • Hydrolysis
  • Protein Conformation
  • Chemokines
  • Cyclic AMP
  • Animals
  • GTP-Binding Proteins
citation count