SIGNAL PROPAGATION AND REGULATION IN THE MATING PHEROMONE RESPONSE PATHWAY OF THE YEAST SACCHAROMYCES-CEREVISIAE

Extracellular signals can affect the rate of proliferation and the sta te of differentiation of eukaryotic cells, Signal transduction pathway s have evolved to detect these signals at the plasma membrane, transmi t them through the cytoplasm and into the nucleus, and thereby generat e the appropriate changes in metabolism and transcription. Much attent ion has been focused recently on regulatory pathways of this sort that lead to activation of a family of protein kinases known as the mitoge n- or messenger-activated, or extracellular signal-regulated protein k inases (MAPKs or ERKs) because this particular class of enzyme is high ly conserved among eukaryotes, as is documented here and in the accomp anying reviews in this issue, The mating pheromone response pathway in a unicellular microbe, the budding yeast Saccharomyces cerevisiae, is perhaps the best understood multicomponent signaling pathway known in any eukaryotic organism, especially at the genetic level, Furthermore , structural homologs and functional analogs of the components of the yeast pheromone response pathway are recapitulated in the signaling sy stems present in multicellular eukaryotes, This article emphasizes rec ent findings and common molecular themes for understanding the organiz ation and regulation of MAPK-dependent signaling cascades that have em erged from biochemical and genetic analysis of the mating pheromone re sponse pathway in yeast, (C) 1994 Academic Press, Inc.