Rice Mutator-Like (MULE) Transposed in Yeast

 

Introduction

 

Transposable elements (TEs), also known as “jumping genes,” are pieces of DNA that can change their genomic position. Transposase is an enzyme that acts as a catalyst for the movement of a TE to another part of the genome and is required for a TE to move. Autonomous TEs encode their own transposases and therefore are capable of moving themselves around the genome. Mutator-like TEs (MULEs) are highly mutagenic autonomous DNA TEs that have been found to be present in a wide range of organisms, including plants, animals, and fungi. Transposons are extremely useful for several molecular biology applications. They can be manipulated to carry genes of interest and stably transfer these genes into an organism’s genome providing long term, stable expression. Alternatively, transposons have also been widely used for gene tagging, a technique that allows a phenotype to be associated with a gene that has been disrupted by TE insertion. The characteristics of TE not only make them valuable tools for research, but also make them appealing as vectors for non-viral gene therapy. However, a major hurdle in using TE-based vectors for gene therapy is the overall efficiency of in vivo gene delivery. The activity of wild-type transposases is known to be low, especially in comparison to viral-based vectors currently used for gene therapy. It has been shown that minor amino acid substitutions can significantly increase transposase activity and it has been suggested that such modifications could greatly increase the utility of transposons for both biotechnology and medical applications.

 

Description of Technology

 

Michigan State University has developed a highly active transposon vector that could be used either as a research tool or gene therapy vector. The vector is a derivative of Os3378, an active MULE-like TE identified in rice. Increased transposon activity was achieved through genetic manipulation of the associated transposase. This vector is especially useful for transgene expression, or gene therapy, not only due to increased activity but also because insertion is highly specific for a 9bp AT-rich sequence which generally occurs in intergenic spaces. Insertion of transgenes into intergenic regions is less likely to disrupt endogenous gene function and thus less likely to cause off target phenotypes.

 

Read more: Dongyan, Z. et al. (2015) Transposition of a Rice Mutator-Like Element in the Yeast Saccharomyces cerevisiae. Plant Cell

 

Key Benefits

  • Highly active: the transposase has been engineered to be more active, thereby increasing gene delivery efficiency
  • Specificity: this transposon system is highly specific for a 9bp AT-rich sequence
  • Complementary technology:  the widely used MuDR/Mu transposons target GC-rich sequences whereas Os3378 targets AT-rich regions. The technologies could be used together in gene tagging applications to obtain comprehensive coverage of the genome
  • Intergenic preference: AT-rich regions tend to be intergenic, therefore insertion of transgene may be less likely to disrupt endogenous genes

 

Applications

  • Research tool
    • Transgene expression
    • Gene tagging vector
  • Gene therapy

 

Patent Status

 

Patent Pending

 

Inventors

 

Ning Jiang, Dongyan Zhao

 

Tech ID

 

TEC2014-0124

 

Patent Information:

For Information, Contact:

Thomas Herlache
Assistant Director
Michigan State University
herlache@msu.edu
Keywords: