Identification of 14 kDa auxin-binding proteins in a tobacco plasma membrane subfraction responsive to auxin.
Auxin binding by tobacco plasma membrane proteins was investigated. After photolabeling with [3H]IAA, 350 polypeptides were resolved on 2D gels and analyzed. Thirteen polypeptides were selected according to physico-chemical criteria. The labeling of three of them was further shown to increase, after treatment of cells with auxin, specifically in that plasma membrane subfraction where the sensitivity to the hormone of the H(+)-ATPase is enhanced by the treatment of cells. These polypeptides were those that exhibited the more specific labeling features according to physico-chemical criteria. They had similar apparent molecular weight (ca 14 kDa) that distinguished them from other auxin-binding proteins described up to now, and exhibited similar amino acid compositions. These 14 kDa polypeptides are proposed to constitute a group of new auxin-binding proteins, potentially involved, within specialized plasma membrane domains, in the stimulation of the proton pump by the hormone.
Szponarski
W
W
Biochimie et Physiologie Moléculaire des Plantes, INRA/ENSA-M/CNRS URA 2133, Montpellier, France. szponarski@ensam.inra.fr
Peltier
J B
JB
Tena
G
G
Rossignol
M
M
D000596:Amino Acids / Q000032:analysis; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism; D019920:Photoaffinity Labels; D010937:Plant Growth Regulators; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D010947:Plants, Toxic; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000302:isolation & purification*; D013347:Subcellular Fractions / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D014026:Nicotiana / Q000737:chemistry* / Q000166:cytology
D000596:Amino Acids; D007210:Indoleacetic Acids; D008565:Membrane Proteins; D010455:Peptides; D019920:Photoaffinity Labels; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C046131:auxin receptor, plant