The fusicoccin receptor of plants is a member of the 14-3-3 superfamily of eukaryotic regulatory proteins.
The receptor for the wilt-inducing phytotoxin fusicoccin was purified to homogeneity from plasma membranes of Commelina communis as a complex with the radioligand [3H]9'-nor-8'-hydroxyfusicoccin. The preparation consisted of two polypeptides with apparent molecular masses of 30.5 kDa and 31.5 kDa and with isoelectric points of around pH 5.2 and 5.3, respectively. The proteins were N-terminally blocked. Internal amino acid sequences were obtained for both polypeptides of the fusicoccin-binding complex. Sequence information, as well as subsequent immunological analysis, proved that both polypeptides are members of the eukaryotic 14-3-3 family, which comprises structurally conserved regulatory proteins of widespread occurrence and a wide range of functions. 14-3-3 isoform(s) constituting the fusicoccin receptor are distinguishable from other cellular 14-3-3 proteins by their tight association with the plasma membrane. Applying temperature-induced Triton X-114 phase separation experiments, they, as well as the target enzyme of fusicoccin action, the H(+)-ATPase, partitioned into the phospholipid-rich fraction which contains the most hydrophobic proteins. The results discussed herein provide a basis for the elucidation of the molecular mechanism of fusicoccin action.
Oecking
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C
Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
Eckerskorn
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C
Weiler
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EW
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry; D006027:Glycosides / Q000494:pharmacology; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins; D010944:Plants / Q000737:chemistry*; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D016415:Sequence Alignment; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D006027:Glycosides; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C080425:fusicoccin receptor protein, plant; C007808:fusicoccin; D000251:Adenosine Triphosphatases