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


  • 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.

published proceedings

  • FEBS Lett

author list (cited authors)

  • Brazill, D. T., Gundersen, R., & Gomer, R. H.

citation count

  • 12

complete list of authors

  • Brazill, DT||Gundersen, R||Gomer, RH

publication date

  • March 1997