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. 1996 Feb;30(4):781-93.
doi: 10.1007/BF00019011.

The C-terminal KDEL sequence increases the expression level of a single-chain antibody designed to be targeted to both the cytosol and the secretory pathway in transgenic tobacco

A Schouten  1 , J Roosien, F A van Engelen, G A de Jong, A W Borst-Vrenssen, J F Zilverentant, D Bosch, W J Stiekema, F J Gommers, A Schots, J Bakker
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The C-terminal KDEL sequence increases the expression level of a single-chain antibody designed to be targeted to both the cytosol and the secretory pathway in transgenic tobacco

A Schouten et al. Plant Mol Biol. 1996 Feb.

Abstract

The effects of subcellular localization on single-chain antibody (scFv) expression levels in transgenic tobacco was evaluated using an scFv construct of a model antibody possessing different targeting signals. For translocation into the secretory pathway a secretory signal sequence preceded the scFv gene (scFv-S). For cytosolic expression the scFv antibody gene lacked such a signal sequence (scFv-C). Also, both constructs were provided with the endoplasmic reticulum (ER) retention signal KDEL (scFv-SK and scFv-CK, respectively). The expression of the different scFv constructs in transgenic tobacco plants was controlled by a CaMV 35S promoter with double enhancer. The scFv-S and scFv-SK antibody genes reached expression levels of 0.01% and 1% of the total soluble protein, respectively. Surprisingly, scFv-CK transformants showed considerable expression of up to 0.2% whereas scFv-C transformants did not show any accumulation of the scFv antibody. The differences in protein expression levels could not be explained by the steady-state levels of the mRNAs. Transient expression assays with leaf protoplasts confirmed these expression levels observed in transgenic plants, although the expression level of the scFv-S construct was higher. Furthermore, these assays showed that both the secretory signal and the ER retention signal were recognized in the plant cells. The scFv-CK protein was located intracellularly, presumably in the cytosol. The increase in scFv protein stability in the presence of the KDEL retention signal is discussed.

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References

    1. EMBO J. 1990 Jan;9(1):101-8 - PubMed
    1. Biochemistry. 1992 Feb 11;31(5):1270-9 - PubMed
    1. Biochem Biophys Res Commun. 1993 Dec 15;197(2):422-7 - PubMed
    1. EMBO J. 1989 Nov;8(11):3171-6 - PubMed
    1. Biotechnology (N Y). 1994 Apr;12(4):396-9 - PubMed

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