Rubi3 Constitutive Promoter

Tech ID: 04.345

Key Features

  • Rubi3 Promoter and Regulatory Sequences
  • High expression monocot promoter – avoiding non-native N-terminal amino acids


The inventors have identified novel 5' expression control elements from the rice rubi3 polyubiquitin gene. These regulatory elements include the rubi3 promoter, a 5' UTR intron sequence, and a downstream enhancing element located within the first 9 nucleotides of the rubi3 coding sequence. Results demonstrate that the promoter is near-constitutive and shows high expression levels compared with 35S, maize ubi1 and rice Act1 in rice suspension cells, transgenic rice and transgenic corn. In addition, the 5' UTR intron also enhances promoter activities, having a significant, positive effect on heterologous gene expression. An increase in expression levels with a variety of promoters has been demonstrated. Mutations introduced around the start codon of the promoter sequence led to further increases in promoter activity. Unlike other Ubiquitin promoter technology the Rubi3 system does not require the incorporation of any non-native protein sequence derived from the Ubiquitin N-terminal.

Note on IP: It is PBL's view that the rubi3 promoter technology is free of the existing third party patents (Mycogen/Dow) in the area of Ubiquitin promoters as the rubi3 promoter inherently lacks a heat shock element as required in the Mycogen/Dow IP, and is also free of existing Monsanto patent applications here claims are directed to a promoter which includes a heat shock element but which is deactivated. Furthemore, the rubi3 technology encompasses a novel rubi3 intron which up-regulates expression from either the rubi3 promoter or an unrelated promoter, and is neither disclosed nor suggested in the patent or technical literature.

For further detailed information please download the non-confidential summary pdf.


Granted: US 8,022,271


Lu J et al (2008).  Gene expression enhancement mediated by the 5' UTR intron of the rice rubi3 gene varied remarkably among tissues in transgenic rice plants.  Molecular Genetics and Genomics; 279(6): 563-72.

Samadder P et al (2008).  Transcriptional and post-transcriptional enhancement of gene expression by the 5’ UTR intron of rice rubi3 gene in transgenic rice cells.  Molecular Genetics and Genomics; 279(4): 429-439.

Sivamani E  and Qu R (2006).  Expression enhancement of a rice polyubiquitin promoter.  Plant Molecular Biology; 60: 225-239.

Contact: Dr Lars von Borcke

Rongda Qu, Sivamani Elumalai
North Carolina State University (Raleigh, USA)