Arabidopsis G-protein β subunit AGB1 interacts with NPH3 and is involved in phototropism.
Heterotrimeric G proteins (Gα, Gβ and Gγ) have pleiotropic roles in plants, but molecular mechanisms underlying them remain to be elucidated. Here we show that Arabidopsis Gβ (AGB1) interacts with NPH3, a regulator of phototropism. Yeast two-hybrid assays, in vitro pull-down assays and bimolecular fluorescence complementation assays showed that AGB1 and NPH3 physically interact. NPH3-null mutation (nph3) is known to completely abolish hypocotyl phototropism. Loss-of-function mutants of AGB1 (agb1-1 and agb1-2) showed decreased hypocotyl phototropism, and agb1/nph3 double mutants showed no hypocotyl phototropism. These results suggest that AGB1 is involved in the NPH3-mediated regulation of phototropism.
Asian Natural Environmental Science Center, The University of Tokyo, Nishitokyo, Tokyo 188-0002, Japan. Electronic address: jeerapornk@anesc.u-tokyo.ac.jp.
Jeeraporn
J
Kansup
Asian Natural Environmental Science Center, The University of Tokyo, Nishitokyo, Tokyo 188-0002, Japan; Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: tsugama@anesc.u-tokyo.ac.jp.
Daisuke
D
Tsugama
Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin 150040, China. Electronic address: shenkuiliu@nefu.edu.cn.
Shenkui
S
Liu
Asian Natural Environmental Science Center, The University of Tokyo, Nishitokyo, Tokyo 188-0002, Japan. Electronic address: takano@anesc.u-tokyo.ac.jp.
Tetsuo
T
Takano
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D044387:GTP-Binding Protein beta Subunits / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018546:Hypocotyl / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009154:Mutation; D018524:Phototropism / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020798:Two-Hybrid System Techniques
C089590:AGB1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D044387:GTP-Binding Protein beta Subunits; C400222:NPH3 protein, Arabidopsis
Arabidopsis; Heterotrimeric G protein β subunit; Nonphototropic hypocotyl 3; Phototropism; Protein–protein interaction