Enhanced nucleic acid constructs for eukaryotic gene expression
The present invention provides polynucleotide vectors for high expression of heterologous genes, and methods for constructing such vectors. Some vectors further comprise novel transposons and transposases that further improve expression. Further disclosed are vectors that can be used in a gene transfer system for stably introducing nucleic acids into the DNA of a cell. The gene transfer systems can be used in methods, for example, but not limited to, gene expression, gene therapy, insertional mutagenesis, or gene discovery.
1. A polynucleotide comprising a piggyBac-like transposon comprising a heterologous polynucleotide flanked by a pair of transposon ends, wherein one transposon end comprises at least 16 contiguous nucleotides from SEQ ID NO: 1 and the other transposon end comprises at least 16 contiguous nucleotides from SEQ ID NO: 2.
2. The polynucleotide of claim 1 , wherein each transposon end comprises inverted terminal repeat (ITR) that is at least 90% identical to SEQ ID NO: 32.
3. The polynucleotide of claim 2 , wherein the transposon comprises two inverted terminal repeat (ITR) sequences, each of which is SEQ ID NO: 32.
4. The polynucleotide of claim 1 , wherein one transposon end comprises a sequence that is at least 90% identical to SEQ ID NO: 1 and the other transposon end is at least 90% identical to SEQ ID NO: 2.
5. The polynucleotide of claim 1 , wherein the heterologous polynucleotide comprises a promoter.
6. The polynucleotide of claim 5 wherein the promoter is an EF1a promoter, a CMV promoter, a GAPDH promoter, a Herpes Simplex Virus thymidine kinase (HSV-TK) promoter, an actin promoter, a PGK promoter, and an ubiquitin promoter.
7. The polynucleotide of claim 5 , wherein the heterologous polynucleotide further comprises a second promoter, and wherein the transcription directions from the first and second promoters are different.
8. The polynucleotide of claim 5 , wherein the promoter is operably linked to one or more of: i) an open reading frame; ii) a selectable marker; iii) a counter-selectable marker; iii) a nucleic acid encoding a regulatory protein; iv) a nucleic acid encoding an inhibitory RNA.
9. The polynucleotide of claim 8 , wherein the selectable marker is a gene encoding one of glutamine synthetase (GS), dihydrofolate reductase (DHFR), or a protein conferring resistance to puromycin, neomycin, hygromycin, zeocin or blasticidin.
10. The polynucleotide of claim 1 , wherein the heterologous polynucleotide comprises one or more sequence elements that increase expression by enhancing RNA processing or export from the nucleus.
11. The polynucleotide of claim 10 , wherein the sequence elements are selected from WPRE, HPRE (SEQ ID NO: 104-105), SAR (SEQ ID NOS: 108-111), AGS (SEQ ID NOS: 106-107).
12. The polynucleotide of claim 1 , wherein the heterologous polynucleotide comprises a pair of insulators.
13. The polynucleotide of claim 12 , wherein the insulators are selected from SEQ ID NOS: 112-113.
14. The polynucleotide of claim 5 , wherein the promoter is active in a eukaryotic cell.
15. The polynucleotide of claim 1 , wherein the heterologous polynucleotide comprises an internal ribosome entry site (IRES) sequences.
16. The polynucleotide of claim 15 , wherein the IRES is one of SEQ ID NOs: 58-100.
17. The polynucleotide of claim 1 , wherein the heterologous polynucleotide comprises a gene encoding an antibody chain.
18. The polynucleotide claim 1 , wherein the heterologous polynucleotide comprises a gene encoding a chimeric antibody receptor.
19. An isolated eukaryotic cell or non-human transgenic animal, whose genome comprises an integrated copy of the polynucleotide of claim 1 .
20. The isolated eukaryotic cell or non-human transgenic animal of claim 19 , which is an isolated eukaryotic cell, wherein the cell is an animal cell.