TY - JOUR
T1 - GTPase acceleration as the rate-limiting step in Arabidopsis G protein-coupled sugar signaling
AU - Johnston, Christopher A.
AU - Taylor, J. Philip
AU - Gao, Yajun
AU - Kimple, Adam J.
AU - Grigston, Jeffrey C.
AU - Chen, Jin Gui
AU - Siderovski, David P.
AU - Jones, Alan M.
AU - Willard, Francis S.
PY - 2007/10/30
Y1 - 2007/10/30
N2 - Heterotrimeric G protein signaling is important for cell-proliferative and glucose-sensing signal transduction pathways in the model plant organism Arabidopsis thaliana. AtRGS1 is a seven-transmembrane, RGS domain-containing protein that is a putative membrane receptor for D-glucose. Here we show, by using FRET, that D-glucose alters the interaction between the AtGPA1 and AtRGS1 in vivo. AtGPA1 is a unique heterotrimeric G protein α subunit that is constitutively GTP-bound given its high spontaneous nucleotide exchange coupled with slow GTP hydrolysis. Analysis of a point mutation in AtRGS1 that abrogates GTPase-accelerating activity demonstrates that the regulation of AtGPA1 GTP hydrolysis mediates sugar signal transduction during Arabidopsis development, in contrast to animals where nucleotide exchange is the limiting step in the heterotrimeric G protein nucleotide cycle.
AB - Heterotrimeric G protein signaling is important for cell-proliferative and glucose-sensing signal transduction pathways in the model plant organism Arabidopsis thaliana. AtRGS1 is a seven-transmembrane, RGS domain-containing protein that is a putative membrane receptor for D-glucose. Here we show, by using FRET, that D-glucose alters the interaction between the AtGPA1 and AtRGS1 in vivo. AtGPA1 is a unique heterotrimeric G protein α subunit that is constitutively GTP-bound given its high spontaneous nucleotide exchange coupled with slow GTP hydrolysis. Analysis of a point mutation in AtRGS1 that abrogates GTPase-accelerating activity demonstrates that the regulation of AtGPA1 GTP hydrolysis mediates sugar signal transduction during Arabidopsis development, in contrast to animals where nucleotide exchange is the limiting step in the heterotrimeric G protein nucleotide cycle.
KW - D-glucose
KW - G protein-coupled receptor
KW - GTPase-accelerating protein
KW - Guanine nucleotide cycle
KW - RGS protein
UR - http://www.scopus.com/inward/record.url?scp=36849042975&partnerID=8YFLogxK
U2 - 10.1073/pnas.0704751104
DO - 10.1073/pnas.0704751104
M3 - Article
C2 - 17951432
AN - SCOPUS:36849042975
SN - 0027-8424
VL - 104
SP - 17317
EP - 17322
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 44
ER -