Improvement of the pBI121 plant expression vector by leader replacement with a sequence combining a poly(CAA) and a CT motif.
To improve expression levels of recombinant proteins in plants, a new leader sequence was designed. Several elements known to enhance gene translation and/or transcription were considered, including the CaMV 35S Inr site, a CT-rich motif often shared by highly expressed plant genes and a poly(CAA) region widespread in tobamovirus and plant leaders. The effect of the synthetic leader on gusA expression was evaluated in genetically modified tobacco plants by measuring the beta-glucuronidase activity and the mRNA level. When compared to the gusA leader of pBI121, the new sequence determined a 8.6-fold and a 12.5-fold increase of enzyme concentration taking into account the whole plant population or the above-average expressors, respectively. Since most pCAMBIA vectors harbour a very short 5'-UTR, identical to a fragment of the pBI121 leader, leader replacement with the sequence herein described is strongly suggested.
De Amicis
Francesca
F
Dipartimento di Scienze Agrarie e Ambientali, University of Udine, Via delle Scienze 208, Udine 33100, Italy.
Patti
Tamara
T
Marchetti
Stefano
S
D020121:5' Untranslated Regions; D001483:Base Sequence; D018900:Dinucleotide Repeats; D005818:Genetic Engineering; D005822:Genetic Vectors; D030821:Plants, Genetically Modified; D020079:Terminal Repeat Sequences; D046509:Tissue Culture Techniques; D014026:Nicotiana / Q000235:genetics
D020121:5' Untranslated Regions