Higher accumulation of F1-V fusion recombinant protein in plants after induction of protein body formation.
Improving foreign protein accumulation is crucial for enhancing the commercial success of plant-based production systems since product yields have a major influence on process economics. Cereal grain evolved to store large amounts of proteins in tightly organized aggregates. In maize, gamma-Zein is the major storage protein synthesized by the rough endoplasmic reticulum (ER) and stored in specialized organelles called protein bodies (PB). Zera (gamma-Zein ER-accumulating domain) is the N-terminal proline-rich domain of gamma-zein that is sufficient to induce the assembly of PB formation. Fusion of the Zera domain to proteins of interest results in assembly of dense PB-like, ER-derived organelles, containing high concentration of recombinant protein. Our main goal was to increase recombinant protein accumulation in plants in order to enhance the efficiency of orally-delivered plant-made vaccines. It is well known that oral vaccination requires substantially higher doses than parental formulations. As a part of a project to develop a plant-made plague vaccine, we expressed our model antigen, the Yersinia pestis F1-V antigen fusion protein, with and without a fused Zera domain. We demonstrated that Zera-F1-V protein accumulation was at least 3x higher than F1-V alone when expressed in three different host plant systems: Ncotiana benthamiana, Medicago sativa (alfalfa) and Nicotiana tabacum NT1 cells. We confirmed the feasibility of using Zera technology to induce protein body formation in non-seed tissues. Zera expression and accumulation did not affect plant development and growth. These results confirmed the potential exploitation of Zera technology to substantially increase the accumulation of value-added proteins in plants.
Alvarez
M Lucrecia
ML
Center for Infectious Diseases and Vaccinology, The Biodesign Institute at Arizona State University, 1001 South McAllister Avenue, Tempe, AZ 85287-5401, USA. lucrecia.alvarez@asu.edu
Topal
Emel
E
Martin
Federico
F
Cardineau
Guy A
GA
D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D015139:Blotting, Southern; D015153:Blotting, Western; D002478:Cells, Cultured; D000455:Medicago sativa / Q000235:genetics / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D015028:Zein / Q000235:genetics / Q000378:metabolism*
D000942:Antigens, Bacterial; C043908:LcrV protein, Yersinia; D052899:Pore Forming Cytotoxic Proteins; D011993:Recombinant Fusion Proteins; D015028:Zein