A fusicoccin binding protein belongs to the family of 14-3-3 brain protein homologs.
The fusicoccin binding protein (FCBP) is a highly conserved plasma membrane protein present in all higher plants tested thus far. It exhibits high- and low-affinity binding for the fungal toxin fusicoccin (FC). We purified the active FCBP from a fraction highly enriched in plasma membrane by selective precipitation and anion exchange chromatography. After SDS-PAGE, the two FCBP subunits of 30 and 31 kD were detected as major bands. Amino acid sequence analysis of the 31-kD polypeptide displayed a high degree of identity with so-called 14-3-3 proteins, a class of mammalian brain proteins initially described as regulators of neurotransmitter synthesis and protein kinase C inhibitors. Thereafter, we affinity purified the 30- and 31-kD FCBP subunits, using biotinylated FC in combination with a monomeric avidin column. Immunodecoration of these 30- and 31-kD FCBP subunits with polyclonal antibodies raised against a 14-3-3 homolog from yeast confirmed the identity of the FCBP as a 14-3-3 homolog. Similar to all 14-3-3 protein homologs, the FCBP seems to exist as a dimer in native form. Thus far, the FCBP is the only 14-3-3 homolog with a receptor-like function. The conserved structure of the 14-3-3 protein family is a further indication that the FCBP plays an important role in the physiology of higher plants.
Korthout
H A
HA
Department of Plant Physiology and Biochemistry, Vrije Universiteit, Amsterdam, The Netherlands.
de Boer
A H
AH
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000254:growth & development; D018554:Avena / Q000737:chemistry*; D001923:Brain Chemistry; D002451:Cell Compartmentation; D003429:Cross Reactions; D018506:Gene Expression Regulation, Plant; D006027:Glycosides / Q000378:metabolism*; D008024:Ligands; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000276:immunology; D010935:Plant Diseases; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D006027:Glycosides; D008024:Ligands; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C080425:fusicoccin receptor protein, plant; C007808:fusicoccin