The RGS proteins add to the diversity of soybean heterotrimeric G-protein signaling.
Regulator of G-protein signaling (RGS) proteins are a family of highly diverse, multifunctional proteins that function primarily as GTPase accelerating proteins (GAPs). RGS proteins increase the rate of GTP hydrolysis by Gα proteins and essentially regulate the duration of active signaling. Recently, we have identified two chimeric RGS proteins from soybean and reported their distinct GAP activities on individual Gα proteins. A single amino acid substitution (Alanine 357 to Valine) of RGS2 is responsible for differential GAP activity. Surprisingly, most monocot plant genomes do not encode for a RGS protein homolog. Here we discuss the soybean RGS proteins in the context of their evolution in plants, their relatedness to non-plant RGS protein homologs and the effect they might have on the heterotrimeric G-protein signaling mechanisms. We also provide experimental evidence to show that the interaction interface between plant RGS and Gα proteins is different from what is predicted based on mammalian models.
Donald Danforth Plant Science Center; St. Louis, MO, USA.
Swarup Roy
SR
Choudhury
Corey S
CS
Westfall
Sona
S
Pandey
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D019143:Evolution, Molecular; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D044385:GTP-Binding Protein alpha Subunits / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D008322:Mammals; D008954:Models, Biological; D010940:Plant Proteins / Q000378:metabolism*; D020710:RGS Proteins / Q000378:metabolism*; D017385:Sequence Homology; D015398:Signal Transduction; D013025:Glycine max / Q000378:metabolism*
D000596:Amino Acids; D044385:GTP-Binding Protein alpha Subunits; D010940:Plant Proteins; D020710:RGS Proteins; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D020962:Heterotrimeric GTP-Binding Proteins