TAL-Tet1 fusion proteins and methods of use thereof
Fusion proteins comprising a DNA binding domain, e.g., a TAL effector repeat array or zinc finger, and a catalytic domain comprising a sequence that catalyzes hydroxylation of methylated cytosines in DNA, and methods of use thereof.
1. A fusion protein comprising
an engineered transcription activator-like (TAL) effector repeat array or a zinc finger protein DNA-binding domain that binds specifically to a DNA sequence that is within 250 bp of a CpG diresidue in a mammalian cell, fused to
a catalytic domain comprising a catalytic domain of Teti comprising amino acids 1580-2052 of SEQ ID NO: 2, and excluding amino acids 584-624 of SEQ ID NO:2, that catalyzes hydroxylation of methylated cytosines in DNA.
2. The fusion protein of claim 1 , further comprising a linker between the DNA binding domain and the catalytic domain.
3. The fusion protein of claim 1 , comprising a plurality of catalytic domains.
4. The fusion protein of claim 1 , wherein the DNA-binding domain comprises a six-finger zinc finger protein.
5. The fusion protein of claim 1 , wherein the catalytic domain consists of amino acids 1418-2136 of Tet1 (SEQ ID NO: 4).
6. A method of reducing methylation of a CpG diresidue in a mammalian cell, the method comprising contacting the cell with a fusion protein of claim 1 , wherein the fusion protein binds to a DNA sequence that is within about 250 bp of the CpG diresidue, and wherein the fusion protein reduces methylation of the CpG diresidue.
7. The method of claim 6 , wherein the cell is a human cell.
8. The method of claim 6 , wherein the DNA sequence is a gene selected from the group consisting of RASSF1A, MGMT, BRCA1, p16, CDH1, TIMP-3, p15, p73, DAPK, APC, and RELN.
9. The method of claim 6 , wherein the DNA sequence is within about 100 bp of the CpG diresidue.
10. The method of claim 6 , wherein the DNA sequence is within about 30 bp of the CpG diresidue.