RNA-guided gene editing and gene regulation
Disclosed herein are Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas) 9-based system related compositions and methods of using said CRISPR/Cas9-based system related compositions for altering gene expression and genome engineering. Also disclosed herein are compositions and methods of using said compositions for altering gene expression and genome engineering in muscle, such as skeletal muscle and cardiac muscle.
1. A DNA targeting system that binds to a human gamma globin gene comprising at least one guide RNA (gRNA) that binds and targets a polynucleotide sequence selected from SEQ ID NO: 33, 34, 35, or 36, or variant thereof.
2. The DNA targeting system of claim 1 , further comprising a fusion protein comprising two heterologous polypeptide domains, wherein the first polypeptide domain comprises a Clustered Regularly Interspaced Short Palindromic Repeats associated (Cas) protein and the second polypeptide domain has an activity selected from the group consisting of transcription activation activity, transcription repression activity, transcription release factor activity, histone modification activity, nuclease activity, nucleic acid association activity, methylase activity, and demethylase activity, and wherein the fusion protein comprises an amino acid sequence selected from SEQ ID NOs: 1 and 674-676.
3. A DNA targeting system that binds to a human gamma globin gene comprising at least one guide RNA (gRNA) and a fusion protein comprising two heterologous polypeptide domains, wherein the first polypeptide domain comprises a Clustered Regularly Interspaced Short Palindromic Repeats associated (Cas) protein and the second polypeptide domain has an activity selected from the group consisting of transcription activation activity, transcription repression activity, transcription release factor activity, histone modification activity, nuclease activity, nucleic acid association activity, methylase activity, and demethylase activity, wherein the at least one guide RNA (gRNA) binds and targets a polynucleotide sequence selected from SEQ ID NO: 33, 34, 35, or 36, or variant thereof, and wherein the fusion protein comprises an amino acid sequence selected from SEQ ID NOs: 1 and 674-676.
4. The DNA targeting system claim 2 , wherein the Cas protein comprises a Cas9, wherein the Cas9 comprises at least one amino acid mutation which knocks out nuclease activity of Cas9.
5. The DNA targeting system of claim 4 , wherein the at least one amino acid mutation is at least one of D10A and H840A.
6. The DNA targeting system of claim 5 , wherein the Cas protein comprises iCas9 (amino acids 36-1403 of SEQ ID NO: 1).
7. The DNA targeting system of claim 2 , wherein the second polypeptide domain of the fusion protein comprises at least one VP16 transcription activation domain repeat or a KRAB domain.
8. The DNA targeting system of claim 7 , wherein the second polypeptide domain of the fusion protein comprises a VP16 tetramer (“VP64”) or a p65 activation domain.
9. The DNA targeting system of claim 2 , wherein the fusion protein further comprises a linker connecting the first polypeptide domain to the second polypeptide domain.
10. An isolated polynucleotide encoding the DNA targeting system of claim 1 .
11. A vector comprising the isolated polynucleotide of claim 10 .
12. A cell comprising the isolated polynucleotide of claim 10 .
13. A method of modulating mammalian gene expression in a cell, the method comprising contacting the cell with the DNA targeting system of claim 1 .
14. A composition for inducing gene expression in a subject, the composition comprising the DNA targeting system of claim 1 .
15. A modified lentiviral vector comprising an isolated polynucleotide encoding the DNA targeting system of claim 2 , the isolated polynucleotide comprising a first polynucleotide sequence encoding the fusion protein and a second polynucleotide sequence encoding the at least one gRNA.
16. A method of activating endogenous gene expression in a subject, the method comprising contacting a cell with the modified lentiviral vector of claim 15 .
17. The method of claim 16 , wherein the subject is suffering from sickle cell disease or thalassaemia.