A synthetic nucleic acid expression system for production of a transcript of interest in a predefined cell-state is provided, the system comprising (a) a first nucleic acid sequence comprising a first promoter operably linked to a nucleic acid sequence encoding a first trans-spliceable pre-mRNA sequence comprising at least one exon encoding a 5′ fragment of said transcript of interest and a first RNA sequence required for spliceosome-dependent trans-splicing; and (b) a second nucleic acid sequence comprising a second promoter operably linked to a nucleic acid sequence encoding a second trans-spliceable pre-mRNA sequence comprising at least one exon encoding a 3′ fragment of said transcript of interest and a second RNA sequence required for spliceosome-dependent trans-splicing; wherein said first promoter and said second promoter are different and each one is specifically regulated by said predefined cell-state.

The present invention provides compositions, systems and methods for using ribozyme-mediated cis-cleavage and trans-splicing of RNA molecules to express proteins or fusion proteins of interest.

The purpose of the present invention is to provide a method for producing a very stable, cyclized mutant protein such that high cyclization efficiency is achieved while the number of amino acids added is minimal and the biological properties of an original protein are maintained. In view of conformational information about the original protein, secondary structure-free regions at N/C terminal portions are deleted. Then, a protein database is screened for proteins with secondary structures similar to those of N/C terminal residues of a secondary structure-forming portion after the deletion. The screening results are used to determine the amino acid length of a loop structure through which the N-terminus and the C-terminus of the secondary structure-forming portion of the original protein are to be connected. A cyclized mutant protein is finally produced having a loop structure with the determined amino acid length.

Provided herein are compositions and systems for reconstitution of RNA molecules, including methods for using these molecules. For example, such molecules can be used to deliver a protein coding sequence over two or more viral vectors (such as AAVs), resulting in reconstitution of the full-length protein in a cell. Such methods can be used to deliver a therapeutic protein, for example to treat a genetic disease or cancer.

The invention relates to an expression construct for the expression of polypeptides in host cells using alternative splicing. The expression construct can be used for the expression of polypeptides such as antibodies, antibody fragments and bispecific antibodies by expressing the gene products required for protein expression at the ratio leading to the highest titres or the best product quality profile.

The present invention relates to an acceptor splice region, as well as uses and applications thereof.

Provided herein are synthetic RNA molecules for reconstitution of RNA molecules, including compositions and methods of using these molecules. For example, such molecules can be used to deliver a protein coding sequence over two or more viral vectors (such as AAVs), resulting in reconstitution of the full-length protein in a cell. Such methods can be used to deliver a therapeutic protein, for example to treat a genetic disease or cancer.

Disclosed are materials and methods for treating diseases of the mammalian eye, and in particular, Usher syndrome 1B (USH1B). The invention provides AAV-based, dual-vector systems that facilitate the expression of full-length proteins whose coding sequences exceed that of the polynucleotide packaging capacity of an individual AAV vector. In one embodiment, vector systems are provided that include i) a first AAV vector polynucleotide that includes an inverted terminal repeat at each end of the polynucleotide and a suitable promoter followed by a partial coding sequence that encodes an N-terminal portion of a full-length polypeptide; and ii) a second AAV vector polynucleotide that includes an inverted terminal repeat at each end of the polynucleotide and a partial coding sequence that encodes a C-terminal portion of a full-length polypeptide, optionally followed by a polyadenylation (pA) signal sequence. In another embodiment, the vector system includes i) a first AAV vector polynucleotide comprising an inverted terminal repeat at each end, a suitable promoter followed by a partial coding sequence that encodes an N-terminal portion of a full-length polypeptide followed by a splice donor site and intron and ii) a second AAV vector polynucleotide comprising an inverted terminal repeat at each end, followed by an intron and a splice-acceptor site for the intron, followed by a partial coding sequence that encodes a C-terminal portion of a full-length polypeptide, optionally followed by a polyadenylation (pA) signal sequence. The coding sequence or the intron sequence in the first and second AAV vectors preferably includes a sequence region that overlaps.

We disclose dumbbell-shaped vectors adapted for efficient expression in mammalian cells. We also disclose a novel method allowing the efficient synthesis of dumbbell-shaped vectors at low cost for delivery of recombinant DNA and RNA into host cells; and the use of dumbbell-shaped vectors for transient expression in, for example, primary human cells.

Novel intron fragments are provided. The intron fragments can increase gene expression to levels equal to or higher than those achieved by the full-length intron while maintaining their ability to increase gene expression even when combined with various types of promoters and splicing donors. Particularly, the intron fragments enable loading of larger transgenes when used in genetic information delivery systems whose size is limited, for example, adeno-associated viruses (AAVs) and rhabdoviruses. Therefore, the use of the intron fragments is expected to extend the range of therapeutic genes.