Abstrakt
Plant cells use sugars mainly as a source or store of energy and carbon skeletons for anabolic reactions and for osmotic regulation. the perception of sugars and their responses are rather complex including the heterotrimeric G protein pathway and a seven-transmembrane RGS molecule. Previously, we found that endocytosis of the 7tm-RGS leads to sustained activation of the G protein pathway in the genetic model arabidopsis. here we show that other plants possess similar endocytosis systems of the 7tm-RGS proteins. a phosphorylation site essential for the endocytosis is well conserved in land plant 7tm-RGS proteins. in addition, conifer and tobacco 7tm-RGS proteins are internalized in response to sugar. these results indicate a universal mechanism to activate G signaling by endocytosis in plant cells that have 7tm-RGS proteins.