Distinct roles for two Galpha-Gbeta interfaces in cell polarity control by a yeast heterotrimeric G protein.

Distinct Roles for Two G{alpha} G Interfaces in Cell Polarity Control by a Yeast Heterotrimeric G Protein

Heterotrimeric G protein signaling outside the realm of seven transmembrane domain receptors.

Heterotrimeric G proteins, consisting of the guanine nucleotide-binding Galpha subunits with GTPase activity and the closely associated Gbeta and Ggamma subunits, are important signaling components for receptors with seven transmembrane domains (7TMRs). These receptors, also termed G protein-coupled receptors (GPCRs), act as guanine nucleotide exchange factors upon agonist stimulation. There is...

Canonical heterotrimeric G proteins regulating mating and virulence of Cryptococcus neoformans.

Perturbation of pheromone signaling modulates not only mating but also virulence in Cryptococcus neoformans, an opportunistic human pathogen known to encode three Galpha, one Gbeta, and two Ggamma subunit proteins. We have found that Galphas Gpa2 and Gpa3 exhibit shared and distinct roles in regulating pheromone responses and mating. Gpa2 interacted with the pheromone receptor homolog Ste3alpha...

Heterotrimeric G protein signaling in the Arabidopsis unfolded protein response.

We present evidence that heterotrimeric G protein signaling is involved in cell death associated with the unfolded protein response (UPR) in Arabidopsis. Seedlings of homozygous agb1-2 (Gbeta-null mutation) mutant plants are markedly more resistant to growth inhibition by the protein glycosylation inhibitor tunicamycin (Tm) than either wild-type plants or gpa1-4 (Galpha-null mutation) mutants. ...

Distinct Roles for Two G –G Interfaces in Cell Polarity Control by a Yeast Heterotrimeric G Protein

Saccharomyces cerevisiae mating pheromones trigger dissociation of a heterotrimeric G protein (G ) into G guanosine triphosphate (GTP) and G . The G dimer regulates both mitogen-activated protein (MAP) kinase cascade signaling and cell polarization. Here, by independently activating the MAP kinase pathway, we studied the polarity role of G in isolation from its signaling role. MAP kinase signal...