Chapter 4 Signaling Systems of Lower Eukaryotes and Their Evolution

The Expanding Roles of GβγSubunits in G Protein–Coupled Receptor Signaling and Drug Action

“…Most filamentous fungi and Dictyostelium also express single Gb and Gg subunits [reviewed in Shpakov and Pertseva (2008)]. Within the filamentous fungi, the sequence of Gb subunits is fairly similar Amino acid sequences for human Gb subunits were obtained from the National Center for Biotechnology Information protein database.…”

Cyclic Nucleotides and Nucleotide Cyclases in Plant Stress Responses

“…Currently an increasing body of literature is accumulating that reports cGMP dependence of many bacterial processes for instance the control of cyst development in the α-proteobacterium Rhodospirillum centenum (Marden et al, 2011). In lower eukaryotes, cGMP is also implicated in signal transduction (Rericha & Parent, 2008;Shpakov & Pertseva, 2008) and Dictyostelium discoideum GCs, which interestingly share topological similarities with mammalian ACs, have been reported (Roelofs et al, 2001a;Roelofs et al, 2001b). In vertebrates, cGMP has been implicated in broad range of physiological processes, many of which are linked to specific receptors (Garbers, 1999).…”

Ste18p Is a Positive Control Element in the Mating Process of Candida albicans

“…However, in the C. albicans system, loss of either the CaG␣ or CaG␤ of the mating pathway heterotrimeric G protein (encoded by CAG1 and STE4, respectively) results in full sterility (18), unlike in S. cerevisiae, where loss of the G␣ subunit leads to constitutive signaling. In Schizosaccharomyces pombe, the pheromone signaling pathway is regulated only by the SpG␣1 subunit; it appears that neither the SpG␤ subunit nor the SpG␥ subunit is involved in this process (19). In Cryptococcus neoformans, there are three G␣ subunits, one G␤ subunit, and two G␥ subunits; CnG␣2 upregulates the pheromone response pathway, while CnG␣3 inhibits the signaling pathway (20).…”