G Proteins

Signaling Shortcut

Science's STKE  28 May 2002:
Vol. 2002, Issue 134, pp. tw191
DOI: 10.1126/stke.2002.134.tw191

The yeast mating response to pheromones involves transmission of signals through a cascade that begins at a cell-surface pheromone receptor, couples to a heterotrimeric GTP-binding protein (G protein), and eventually activates a mitogen-activated protein kinase (MAPK). Metodiev et al. report that the subsequent adaptation response to pheromones relies on this same general pathway but uses a shortcut. The Gα subunit of the G protein interacts directly with the downstream MAPK to down-regulate the mating signal. This strategy of circumvention may be applicable to other G-protein-stimulated MAPK cascades in higher eukaryotes.

M. V. Metodiev, D. Matheos, M. D. Rose, D. E. Stone, Regulation of MAPK function by direct interaction with the mating-specific Gα in yeast. Science 296, 1483-1486 (2002). [Abstract] [Full Text]