tailieunhanh - Báo cáo Y học: A complex fruit-specific type-2 ribosome-inactivating protein from elderberry (Sambucus nigra) is correctly processed and assembled in transgenic tobacco plants

Laboratory for Phytopathology and Plant Protection, Katholieke Universiteit Leuven, Belgium; 2Institut de Pharmacologie et Biologie Structurale, UMR-CNRS 5089, Toulouse Cedex, France; 3Rega Institute, Laboratory of Molecular Immunology, Katholieke Universiteit Leuven, Belgium Fruits of elderberry (Sambucus nigra) express small quantities of a type-2 ribosome-inactivating protein with an exclusive specificity towards the NeuAc(a2,6)Gal/GalNAc disaccharide and a unique molecular structure typified by the occurrence of a disulfide bridge between the B-chains of two adjacent protomers | Eur. J. Biochem. 269 2897-2906 2002 FEBS 2002 doi A complex fruit-specific type-2 ribosome-inactivating protein from elderberry Sambucus nigra is correctly processed and assembled in transgenic tobacco plants Yina Chen1 Frank Vandenbussche1 Pierre Rouae2 Paul Proost3 Willv J. Peumans1 B and Els Jb Mb Van Damme1 1Laboratory for Phytopathology and Plant Protection Katholieke Universiteit Leuven Belgium 2Institut de Pharmacologie et Biologie Structurale UMR-CNRS 5089 Toulouse Cedex France 3Rega Institute Laboratory of Molecular Immunology Katholieke Universiteit Leuven Belgium Fruits of elderberry Sambucus nigra express small quantities of a type-2 ribosome-inactivating protein with an exclusive specificity towards the NeuAc a2 6 Gal GalNAc disaccharide and a unique molecular structure typified by the occurrence of a disulfide bridge between the B-chains of two adjacent protomers. A cDNA clone encoding this so-called Sambucus nigra fruit specific agglutinin I SNA-If was isolated and expressed in tobacco Samsun NN under the control of the 35S cauliflower mosaic virus promoter. Characterization of the purified protein indicated that the recombinant SNA-If from tobacco leaves has the same molecular structure and biological activities as native SNA-If from elderberry fruits demonstrating that transgenic tobacco plants are fully capable of expressing and correctly processing and assembling a type-2 ribosome-inactivating protein with a complex molecular structure. None of the transformants showed a phenotypic effect indicating that the ectopically expressed SNA-If does not affect the viability of the tobacco cells. Bioassays further demonstrated that none of the transgenic lines exhibited a decreased sensitivity to infection with tobacco mosaic virus suggesting that the elderberry type-2 RIP SNA-If does not act as an antiviral agent in planta. Keywords elderberry ribosome-inactivating protein Sam-bucus nigra transgenic tobacco. .