TY - JOUR
T1 - An intronless form of the tobacco extensin gene terminator strongly enhances transient gene expression in plant leaves
AU - Rosenthal, Sun Hee
AU - Diamos, Andrew G.
AU - Mason, Hugh S.
N1 - Publisher Copyright:
© 2018, Springer Science+Business Media B.V., part of Springer Nature.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Key message: We have found interesting features of a plant gene (extensin) 3′ flanking region, including extremely efficient polyadenylation which greatly improves transient expression of transgenes when an intron is removed. Its use will greatly benefit studies of gene expression in plants, research in molecular biology, and applications for recombinant proteins. Abstract: Plants are a promising platform for the production of recombinant proteins. To express high-value proteins in plants efficiently, the optimization of expression cassettes using appropriate regulatory sequences is critical. Here, we characterize the activity of the tobacco extensin (Ext) gene terminator by transient expression in Nicotiana benthamiana, tobacco, and lettuce. Ext is a member of the hydroxyproline-rich glycoprotein (HRGP) superfamily and constitutes the major protein component of cell walls. The present study demonstrates that the Ext terminator with its native intron removed increased transient gene expression up to 13.5-fold compared to previously established terminators. The enhanced transgene expression was correlated with increased mRNA accumulation and reduced levels of read-through transcripts, which could impair gene expression. Analysis of transcript 3′-ends found that the majority of polyadenylated transcripts were cleaved at a YA dinucleotide downstream from a canonical AAUAAA motif and a UG-rich region, both of which were found to be highly conserved among related extensin terminators. Deletion of either of these regions eliminated most of the activity of the terminator. Additionally, a 45 nt polypurine sequence ~ 175 nt upstream from the polyadenylation sites was found to also be necessary for the enhanced expression. We conclude that the use of Ext terminator has great potential to benefit the production of recombinant proteins in plants.
AB - Key message: We have found interesting features of a plant gene (extensin) 3′ flanking region, including extremely efficient polyadenylation which greatly improves transient expression of transgenes when an intron is removed. Its use will greatly benefit studies of gene expression in plants, research in molecular biology, and applications for recombinant proteins. Abstract: Plants are a promising platform for the production of recombinant proteins. To express high-value proteins in plants efficiently, the optimization of expression cassettes using appropriate regulatory sequences is critical. Here, we characterize the activity of the tobacco extensin (Ext) gene terminator by transient expression in Nicotiana benthamiana, tobacco, and lettuce. Ext is a member of the hydroxyproline-rich glycoprotein (HRGP) superfamily and constitutes the major protein component of cell walls. The present study demonstrates that the Ext terminator with its native intron removed increased transient gene expression up to 13.5-fold compared to previously established terminators. The enhanced transgene expression was correlated with increased mRNA accumulation and reduced levels of read-through transcripts, which could impair gene expression. Analysis of transcript 3′-ends found that the majority of polyadenylated transcripts were cleaved at a YA dinucleotide downstream from a canonical AAUAAA motif and a UG-rich region, both of which were found to be highly conserved among related extensin terminators. Deletion of either of these regions eliminated most of the activity of the terminator. Additionally, a 45 nt polypurine sequence ~ 175 nt upstream from the polyadenylation sites was found to also be necessary for the enhanced expression. We conclude that the use of Ext terminator has great potential to benefit the production of recombinant proteins in plants.
KW - Intron
KW - Plant based expression
KW - Polyadenylation
KW - Polypurine sequence
KW - Read-through transcription
KW - Tobacco extensin terminator
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U2 - 10.1007/s11103-018-0708-y
DO - 10.1007/s11103-018-0708-y
M3 - Article
C2 - 29429129
AN - SCOPUS:85041907173
SN - 0167-4412
VL - 96
SP - 429
EP - 443
JO - Plant Molecular Biology
JF - Plant Molecular Biology
IS - 4-5
ER -