title: Characterization of a 34-kDa soybean binding protein for the syringolide elicitors.
abstract: Syringolides are water-soluble, low-molecular-weight elicitors that trigger defense responses in soybean cultivars carrying the Rpg4 disease-resistance gene but not in rpg4 cultivars. 125I-syringolide 1 previously was shown to bind to a soluble protein(s) in extracts from soybean leaves. A 34-kDa protein that accounted for 125I-syringolide 1 binding activity was isolated with a syringolide affinity-gel column. Partial sequences of internal peptides of the 34-kDa protein were identical to P34, a previously described soybean seed allergen. In soybean seeds, P34 is processed from a 46-kDa precursor protein and was shown to have homology with thiol proteases. P34 is a moderately abundant protein in soybean seeds and cotyledons but its level in leaves is low. cDNAs encoding 46-, 34-, and 32-kDa forms of the soybean protein were cloned into the baculovirus vector, pVL1392, and expressed in insect cells. The resulting 32- and 34-kDa proteins, but not the 46-kDa protein, exhibited ligand-specific 125I-syringolide binding activity. These results suggest that P34 may be the receptor that mediates syringolide signaling.
authors.affiliation: Department of Plant Pathology, University of California, Riverside, CA 92521, USA.
authors.forename: C
authors.initials: C
authors.lastname: Ji
authors.forename: C
authors.initials: C
authors.lastname: Boyd
authors.forename: D
authors.initials: D
authors.lastname: Slaymaker
authors.forename: Y
authors.initials: Y
authors.lastname: Okinaka
authors.forename: Y
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: S L
authors.initials: SL
authors.lastname: Midland
authors.forename: J J
authors.initials: JJ
authors.lastname: Sims
authors.forename: E
authors.initials: E
authors.lastname: Herman
authors.forename: N
authors.initials: N
authors.lastname: Keen
mesh_terms: D000485:Allergens; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D006027:Glycosides / Q000378:metabolism*; D006090:Gram-Negative Bacteria / Q000472:pathogenicity; D008969:Molecular Sequence Data; D010935:Plant Diseases; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D011956:Receptors, Cell Surface / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013025:Glycine max
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C090803:Gly m I protein, Glycine max; D006027:Glycosides; D010940:Plant Proteins; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins