35S-enhanced mas promoter
Calgene has two granted patents, one in the U.S. and one in Canada on a promoter region comprising a UAS of the CaMV 35S gene linked to a transcription initiation region. The patent defines a transcription/translation region of mas as including the sequences responsible for initiating transcription and effecting translation of the mas gene derived from the octopine Ti plasmid of A. tumefaciens. A mas promoter is included within the transcription/translation region. The region comprises the TATA box, an upstream activating region (UAS) and a transcription start site. As described in the patents, the DNA sequences of the region can correspond to:
- from -625 bp upstream the transcriptional start site to +60 bp downstream of the start site;
- from -300 bp upstream the transcriptional start site to +60 bp downstream of the start site; or
- from -300 bp to the start site.
The UAS or upstream activating region (UAR) of the CaMV 35S-enhanced mas promoter can correspond to a DNA sequence:
- from the -25 position of the CaMV 35S promoter to the -360 position;
- from the -45 position to -90 position; or
- from the -25 position or -45 position to the -168 position.
The mas promoter alone is a weak promoter that is active in all tissues but which drives gene expression at different levels, being highly expressed in apical shoots and roots. The promoter of the invention, which combines the mas promoter with the UAR of the CaMV 35S increases levels of expression to about 5 to 10-fold higher than the strong double CaMV 35S promoter, according to the patent.
Some bibliographic data and a summary of the independent claims of the granted patents are presented in the following table.