How Engineered TALE Proteins Can Edit Genes

This patent describes engineered DNA-binding proteins called TALEs, which are shortened and modified to precisely target and edit specific DNA sequences in cells, potentially for gene therapy.

What it covers

This patent describes new, engineered DNA-binding proteins called Transcription Activator-Like Effectors (TALEs). These TALE proteins are designed to be "non-naturally occurring" (Claim 1), meaning they are not found in nature but are custom-built. The key is that they are significantly shortened: the "N-terminal region lacks at least 152 amino acids" and the "C-terminal region is truncated to residue C+63" (Claim 1). These shortened TALE proteins still contain "two or more TALE-repeat units" with specific "repeat variable di-residues (RVDs)" (Claim 1), which are like recognition codes for specific DNA letters. Some of these RVDs can even be "atypical" (Claim 2), allowing for new DNA targeting possibilities. These engineered proteins can also be combined with "functional domains" (Claim 6), such as a "nuclease domain" (Claim 8) to cut DNA, or a "transcriptional activator" (Claim 7) to turn genes on. For example, a cell could be given a polynucleotide (DNA instruction) (Claim 10) that tells it to make one of these custom TALE proteins, which then finds a specific gene, cuts it, and allows for gene editing.

What it doesn't cover

• —Naturally occurring TALE proteins that have not been engineered with specific N-terminal truncations of at least 152 amino acids and C-terminal truncations to C+63.
• —Gene editing systems that do not use TALE DNA-binding domains, such as CRISPR-Cas systems or zinc finger nucleases.
• —TALE proteins that do not contain at least two TALE-repeat units with RVDs.
• —Polypeptides that do not bind to DNA.
• —Pharmaceutical compositions that do not contain either the isolated polynucleotide or the isolated cell described in the claims.

The clever bit

The novelty lies in creating significantly shortened TALE proteins by specific truncations of their N-terminal and C-terminal regions, while still maintaining their ability to bind DNA and potentially incorporating "atypical" RVDs. This engineering allows for more compact and potentially more efficient gene-editing tools.

Why it matters

Gene editing technologies like those involving TALE proteins offer ways to precisely modify DNA, which could lead to new treatments for genetic diseases. By being able to turn genes on or off, or even correct faulty DNA sequences, these tools are foundational for developing advanced therapies. This technology is a key part of the broader field of genetic engineering, impacting drug discovery and personalized medicine.

Real-world examples

• 1.Gene therapies for genetic disorders
• 2.Research tools for studying gene function
• 3.Development of disease models in cells
• 4.Engineered cell lines for drug screening