Applications by Mendel Biotechnology Inc.

Mendel is a US company located in Hayward, California. Deriving its name from the “father of genetics”, Gregor Mendel, the company was founded in early 1997 with the idea that controlling gene expression would lead to new ways of manipulating plant growth and development.

Mendel’s main interest in Arabidopsis is the 1,800-or-so transcription factors that control the expression of ~27,000 Arabidopsis genes. Accordingly, Mendel has applied for patents over a large number of Arabidopsis transcription factors. Presumably this strategy relies on the fact that control of expression of genes via transcription factors is one way in which useful new phenotypes may be engineered into flowering plants (including many agronomically important crops). Since transcription factors are expected to play important roles in plant development, it is expected that Arabidopsis transcription factors may be functionally and structurally similar to, and highly homologous with transcription factors of other flowering plants.  Thus a claim on Arabidopsis transcription factors may also effectively be a claim over the same gene in many other flowering plants.

Transcription Factors

RNA polymerases (RNAPs) are enzymes involved in the process of transcription (transcribing an RNA molecule using DNA as a template).  While prokaryotic RNAP can recognise gene promoters and initiate transcription from the proper start point, the efficiency of the process is further controlled by trans-acting proteins called Transcription Factors (TFs). In both eukaryotes and prokaryotes, the process of transcription is tightly regulated for many genes and one way in which the cell is able to control transcription is through the use of TFs. In eukaryotes RNAP II requires the presence of a group of auxiliary proteins (general Transcription factors) to be able to recognise gene promoters. Hence production of mRNA in eukaryotes requires the presence of general TFs, and may also be further controlled by the presence of gene-specific TFs.

TFs are proteins that bind to specific DNA sequences within the promoter or enhancer regions of a gene and in so doing are able to control the transcription of the gene. They may either decrease (repressors) or increase (activators) the level of transcription. They are often involved in the final step in a signal transduction pathway and can be activated or deactivated by other proteins higher in the pathway. TFs can be recognised from EST and genomic DNA sequencing projects based on the fact that they often contain sequence motifs such as: zinc fingers, helix-turn-helixs, and basic-helix-loop-helix (for DNA binding) and leucine zippers (for interaction between TFs).

Patent Documents Involving Transcription Factors

We have chosen one patent application by Mendel Biotechnology as an example of its patenting strategy towards transcription factors.  The patent application US 2004/0019927 A1 attempts to claim a large group of Arabidopsis transcription factors and related sequences in plants.  This is the largest of the Mendel patent applications for bulk sequences that we were able to find (although there may be more), others also exist that claim either individual or small groups of TFs. Analysis of granted TF patents are discussed in Chapter 7.