Involvement of thiol groups in blue-light-induced phosphorylation of a plasma membrane-associated protein from coleoptile tips of Zea mays L.
Light-induced phosphorylation of a 114 kDa protein in plasma membranes isolated from the tips of maize coleoptiles was investigated in the presence of several thiol reagents at the concentration of 1 mM. Dark phosphorylation of the protein was not affected but light-induced phosphorylation was inhibited 50% with iodoacetamide, 75% with N-ethylmaleimide and 93% with N-phenylmaleimide. Previous incubation of the inhibitors with mercaptoethanol abolished the inhibitory activity completely. N-phenyl-maleimide showed the same inhibition whether it was applied before or after irradiation of the sample. Involvement of thiol group(s) in processes after photoexcitation is discussed.
Rüdiger
Wolfhart
W
Botanisches Institut der Universität München, Menzinger Str. 67, D-80638 München Department of Plant Biology, Carnegie Institution of Washington, 290 Panama Street, Stanford, CA 94305-1297, U.S.A.
Briggs
Winslow R
WR
Botanisches Institut der Universität München, Menzinger Str. 67, D-80638 München Department of Plant Biology, Carnegie Institution of Washington, 290 Panama Street, Stanford, CA 94305-1297, U.S.A.
D002462:Cell Membrane / Q000378:metabolism; D018548:Cotyledon; D003624:Darkness; D004591:Electrophoresis, Polyacrylamide Gel; D005033:Ethylmaleimide / Q000494:pharmacology; D007460:Iodoacetamide / Q000494:pharmacology; D008027:Light; D008301:Maleimides / Q000494:pharmacology; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000528:radiation effects; D008970:Molecular Weight; D010766:Phosphorylation; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D003313:Zea mays / Q000378:metabolism*
D008301:Maleimides; D008565:Membrane Proteins; D013439:Sulfhydryl Reagents; C028525:N-phenylmaleimide; D005033:Ethylmaleimide; D007460:Iodoacetamide