Journal article
Two jasmonate-inducible myrosinase-binding proteins from Brassica napus L. seedlings with homology to jacalin
Two homologous but different cDNAs encoding a 97-kDa and a 70-kDa protein from Brassica napus L. seedlings have been characterized. Both proteins contain sequence motifs with high homology to the IgA binding lectin, jacalin, and the deduced 97-kDa protein contains the peptide sequences of myrosinase-binding protein.
The 70-kDa and the 97-kDa protein can both be isolated as a complex containing myrosinase, indicating they indeed are myrosinase-binding proteins. We provide evidence that the 70-kDa protein binds IgA in vitro, and therefore classify the protein as a jacalin-type lectin. Both the 97-kDa and the 70-kDa proteins are encoded by a small number of genes in the Brassica genome.
The mRNA for the 97-kDa protein is detected in both light- and dark-grown seedlings, whereas the mRNA for the 70-kDa protein is mainly detected in etiolated seedlings. The transcript levels for both proteins are transient and are rapidly increased by methyl jasmonate. The 70-kDa protein is synthesized de novo during germination and accumulates mainly in the hypocotyl and in the root.
By immunogold labeling we show that a few cells scattered in the cotyledons of young seedlings (approx. 5% of total cells), contain protein-body-like structures with the 70-kDa protein. These bodies are present in a 10,000 g pellet from which the 70-kDa protein can be extracted by sodium carbonate. In addition, the 70-kDa protein is detected in the amorphous structures of the vacuole in a few cells of the cotyledon, the hypocotyl and the root.
Language: | English |
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Publisher: | Springer-Verlag |
Year: | 1998 |
Pages: | 295-304 |
Journal subtitle: | An International Journal of Plant Biology |
ISSN: | 00320935 and 14322048 |
Types: | Journal article |
DOI: | 10.1007/s004250050259 |
70-kDa protein, Brassica 97-kDa protein, Brassica Amino Acid Sequence Blotting, Northern Blotting, Southern Brassica Carrier Proteins Cyclopentanes DNA, Complementary Germination Glycoside Hydrolases Intracellular Signaling Peptides and Proteins Jasmonate Key words: Brassica Lectin Lectins Legacy Microscopy, Electron Molecular Sequence Data Myrosinase-binding protein Oxylipins Plant Lectins Protein Binding Protein body (immunocytochemistry) RNA, Messenger Sequence Homology, Amino Acid Subcellular Fractions Vacuole jacalin jasmonic acid thioglucosidase