Summary
The most abundant protein in seeds of Brassica napus (L.) is cruciferin, a legumin-like 12S storage protein. By in vitro translation of embryo RNA, and pulse-chase labelling of cultured embryos with 14C-leucine, we have shown that the 30 kd α polypeptides and 20 kd β polypeptides of cruciferin are synthesized as a family of 50 kd precursors which are cleaved post-translationally. One member of the cruciferin family was cloned from embryo cDNA and sequenced. The nucleotide sequence of the cruciferin cDNA clone, pC1, contains one long open reading frame, which originates in a hydrophobic signal peptide region. Therefore, the complete sequence of the cruciferin mRNA was obtained by primer extension of the cDNA. The predicted precursor polypeptide is 488 amino acids long, including the 22 amino acids of the putative signal sequence. The amino acid composition of cruciferin protein is very similar to the predicted composition of the precursor. Comparison with an amino acid sequence of legumin from peas, deduced from the nucleotide sequence of a genomic clone, shows that the α polypeptide precedes the β polypeptide on the precursor. Cruciferin and legumin share 40% homology in the regions which can be aligned. However, cruciferin contains a 38 amino acid region high in glutamine and glycine in the middle of the α subunit, which is absent in legumin. Legumin has a highly charged region, 57 amino acids long, at the carboxyl-end of the α subunit, which is not found in cruciferin. Both of these regions appear to have originated by reiteration of sequences. re]19850513 ac]19850715
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
CrouchML, SussexIM: Development and storage-protein synthesis in Brassica napus L. embryos in vivo and in vitro. Planta 153:64–74, 1981.
CrouchML, TenbargeKM, SimonAE, FerlR: cDNA clones for Brassica napus seed storage proteins: evidence from nucleotide sequence analysis that both subunits of napin are cleaved from a precursor polypeptide. J Mol Appl Genet 2:273–283, 1983.
DerbyshireE, WrightDJ, BoulterD: Legumin and vicilin storage proteins of legume seeds. Phytochemistry 15:3–24, 1976.
GatehouseJA, CroyRRD, BoulterD: The synthesis and structure of pea storage proteins. CRC Critical Rev Plant Sci 1:287–314, 1984.
GhoshPK, ReddyVB, PiatakM, LebowitzP, WeissmanSM: Determination of RNA sequences by primer directed synthesis and sequencing of their cDNA transcripts. Methods Enzymol 65:580–595, 1980.
GodingLA, BhattyRS, FinlaysonAJ: The characterization of the 12S ‘globulin’ from rapeseed and its glycoprotein component. Can J Biochem 48:1096–1103, 1970.
JonesP: Analysis of radiolabeled lymphocyte proteins by one- and two-dimensional polyacrylamide gel electrophoresis. In: MishellBB, ShiigiSM (eds). Selected Methods in Cellular Immunology, Freeman, San Francisco, 1980.
LarocheM, AspartL, DelsenyM, PenonP: Characterization of radish (Raphanus sativus) storage proteins. Plant Physiol 74:487–493, 1984.
LonnerdalB, JansonJ-C: Studies on Brassica seed protein. I. The low molecular weight proteins in rapeseed. Isolation and characterization. Biochim Biophys Acta 278:175–183, 1972.
LycettGW, CroyRRD, ShirsatAH, BoulterD: The complete nucleotide sequence of a legumin gene from pea (Pisum sativum L.). Nucl Acids Res 12:4493–4506, 1984.
MarcoYA, ThanhVH, TumerNE, ScallonBJ, NielsenNC: Cloning and structural analysis of DNA encoding A2B1a subunit of glycinin. J Biol Chem 259:13436–13441, 1984.
MaxamAM, GilbertW: Sequencing end-labeled DNA with base-specific chemical cleavages. Methods Enzymol 65:499–560, 1980.
MahoneyWC, HoggRW, HermodsonMA: The amino acid sequence of the D-galactose-binding protein from Escherichia coll B/r*. J Biol Chem 256:4350–4356, 1981.
MessingJ, GeraghtyD, HeideckerG, HuN-T, KridlJ, RubensteinI: Plant gene structure. In: KosugeT, MeredithCP, HollaenderA (eds) Genetic Engineering of Plants. Plenum Press, New York, 1984, pp 211–228.
MiflinBJ, FordeBG, KreisM, RahmanS, FordeJ, ShewryPR: Molecular biology of the grain storage proteins of the Triticeae. Phil Trans R Soc Lond B 304:333–339, 1984.
MoreiraMA, HermodsonMA, LarkinsBA, NielsenNC: Partial characterization of the acidic and basic polypeptides of glycinin. J Biol Chem 254:9921–9926, 1979.
O'FarrellPZ, GoodmanHM, O'FarrellPH: High resolution two-dimensional electrophoresis of basic as well as acidic proteins. Cell 12:1133–1142, 1977.
OhmiyaM, HaraI, MatsubaraH: Pumpkin (Cucurbita sp.) speed globulin IV. Terminal sequences of the acidic and basic peptide chains and identification of a pyroglutamyl peptide chain. Plant Cell Physiol 21:157–167, 1980.
SharonN, LisH: Comparative biochemistry of plant glycoproteins. Biochem Soc Trans 7:783–799, 1979.
SchwenkeKD, RaabB, LinowK-J, PahtzW, UhligJ: Isolation of the 12S globulin from Rapeseed (Brassica napus L.) and characterization as a ‘neutral’ proteins. Die Nahrung 25:271–280, 1981.
SchwenkeKD, RaabB, PlietzP, DamaschunG: The structure of the 12S globulin from rapeseed (Brassica napus L.). Die Nahrung 27:165–175, 1983.
VonHeijneG: Patterns of amino acids near signal-sequence cleavage sites. Eur J Biochem 133:17–21, 1983.
WalburgG, LarkinsBA: Oat seed globulin. Subunit characterization and demonstration of its synthesis as a precursor. Plant Physiol 72:161–165, 1983.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Simon, A.E., Tenbarge, K.M., Scofield, S.R. et al. Nucleotide sequence of a cDNA clone of Brassica napus 12S storage protein shows homology with legumin from Pisum sativum . Plant Mol Biol 5, 191–201 (1985). https://doi.org/10.1007/BF00015683
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00015683