Isolation of a novel auxin receptor from soluble fractions of rice (Oryza sativa L.) shoots.
An auxin binding protein (ABP) was isolated from the shoots of rice seedlings and characterized. The ABP was found to be a monomer with a molecular mass of 57 kDa and play a crucial role via auxin binding in regulating H+ translocation activity of the plasma membrane in a typical biphasic manner. The results of binding equilibrium experiments indicate that the ABP binds indole 3-acetic acid with a high affinity (Kd = 1.9 x 10(-8) M), having four primary binding sites for auxin and some secondary sites with low auxin affinities. The ABP appears to have an unambiguous auxin receptor function.
Kim
Y S
YS
Department of Agricultural Chemistry, College of Agriculture and Life Sciences, Seoul National University, Suwon, South Korea.
Kim
D
D
Jung
J
J
D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D007700:Kinetics; D012275:Oryza / Q000378:metabolism*; D010937:Plant Growth Regulators; D010940:Plant Proteins; D018520:Plant Shoots; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C046131:auxin receptor, plant; C030737:indoleacetic acid; D006180:Proton-Translocating ATPases