A Systems Approach
Gene expression is a complex process with many interacting components. GrassRoots takes a systems biology approach to understanding and controlling those components. Our unique technology targets multiple points of control to deliver strong, reliable gene expression.
Endogenous or Synthetic
Using high-resolution gene expression data, GrassRoots has discovered endogenous expression elements from several plant species. Some elements direct high-level gene expression in all tissues, while others are highly targeted.
GrassRoots has also developed a proprietary approach for designing fully synthetic expression elements. These elements have no detectable homology to natural sequences, yet drive comparable levels of gene expression.
The DNA sequence immediately 5’ of the gene, promoters have primary responsibility for directing transcription of DNA into messenger RNA. GrassRoots has characterized the expression profiles of hundreds of endogenous promoters across multiple tissues and multiple conditions using our RootArray technology. We have also designed hundreds of synthetic promoters and assayed their activity in planta.
Certain introns are known to boost gene expression in plants though a process termed Intron-Mediated Enhancement (IME). GrassRoots has identified and characterized a variety of enhancing introns, both endogenous and synthetic.
The 5’ and 3’ untranslated regions are believed to play an important role in translation, affecting the efficiency with which mRNA leads to actual protein product. The 3’ UTR is also a common target for small RNAs that trigger degradation, affecting overall expression level and possibly expression patterning. GrassRoots expression profiling and synthetic expression element technologies also apply to UTRs.
Sometimes called cis regulatory modules (CRMs), enhancers often influence transcription from a significant distance in the genome. This can make them difficult to identify directly. However, GrassRoots is using a combination of bioinformatic and experimental methods to discover enhancers on a genome-wide scale.
In the cell, DNA is not linear; it is wrapped around nucleosomes and packaged into a complex, three-dimensional structure. This 3-D structure is thought to provide an important additional layer of regulation on gene expression. GrassRoots is exploring ways to include chromatin-control elements in its synthetic expression elements.