Nopaline synthase

Human serum albumin was the first full-length human protein to be expressed in the leaves of a transgenic plant (both tobacco and potato leaves were shown to express the protein). This report was published in 1990 [18]. Four years earlier, Barta and colleagues had demonstrated the expression of human growth hormone in tobacco and sunflower callus, and the protein was expressed as a fusion with the Agrohacterium tumefaciens nopaline synthase enzyme [17]. 

Human growth hormone was expressed as fusion with the Agrobacterium tumefaciens nopaline synthase enzyme but only transcript was detectable... 

This enzyme [EC 1.5.1.19], also known as D-nopaline synthase, catalyzes the reaction of Al -(D-l,3-dicarboxy-propyl)-L-arginme with NADP+ and water to produce L-arginine, NADPH, and a-ketoglutarate (or, 2-oxoglu-tarate). In the reverse direction, the enzyme catalyzes the formation of D-nopaline from L-arginine as well as D-ornaline from L-ornithine. 

Very little is known about plant terminators. It has not been determined whether an animal terminator can be functional in plants or not. Until such information is available, it is safer to use a plant terminator for the maximum expression of a foreign gene. The nopaline synthase nos terminator is most frequently used although several other plant terminators have also been isolated. 

Fig. 7. Diagrams of the schemes for modifying levels of A, alcohol dehydrogenase and B, pyruvate decarboxylase activity and testing for survival of anoxia. In A, constructs contain the 35S promoter of the cauliflower mosaic virus (35S) driving expression of the cotton Adh cDNA in either the sense (Adh) or antisense (hdA) orientation, linked to the 3 termination signal of the nopaline synthase gene (Nos). Alternatively, the expression of cotton Adh cDNA is under control of the pea Adh promoter sequence (pea Adh). In B, either the 35S promoter or the pea Adh promoter is used to drive expression of the maize pyruvate decarboxylase cDNA (Pdc), linked to a Nos 3 termination sequence. Constructs are introduced into cotton via Agrobacterium tumefaciens-mediated infection of cotton. Transformed cotton callus is then assayed for its ability to survive anoxia.

Hex motif are found in the octopine synthase (ocs) and nopaline synthase (nos) promoters of the Ti-plasmids (Bouchez et al., 1989), as well as in the cauliflower mosaic virus 35S promoter (as-1 motif) (Katagiri et al.,... 

Fig. 1. Schematic representation of Elcd expression cassette. CaMV 35Sp, cauliflower mosaic virus promoter NOS, nopaline synthase transcription termination signal Elcd, catalytic domain of El gene VSPP, soybean vegetative storage protein P leader sequence to target the protein to apoplast (15).

The E. coli mutant EPSPS gene was engineered into a plant expression vector (pMON8078) and used for transformation of tobacco leaf discs. In this construct, the mutant EPSPS gene was driven by the CaMV 35S promoter and the 3 -polyadenylation signal was derived from the nopaline synthase gene. 

Barta A. The expression of a nopaline synthase human growth hormone chimaeric gene in transformed tobacco and sunflower callus tissue. Plant Mol. Biol., 1986 6 347-357. 

The nopaline-synthase NPT-II fusions made in these experiments provided the basis for constructing a wide range of non-... 

Figure 6. Structure of /3-glucuronidase expression cassettes. TER is a 260 bp polyadenylation signal from the nopaline synthase gene (50). The degradative activity of a "bad batch" of Smal was used to make three different reading frames at lacZ and GUS. Translational and transcriptional fusions can easily be made in this vector.

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