Compositions and methods for the expression of CRISPR guide RNAs using the H1 promoter
The presently disclosed subject matter provides compositions and methods for the expression of CRISPR guide RNAs using the H1 promoter. In particular, compositions and methods are provided for the use of the H1 promoter to express CRISPR guide RNA (gRNA) with altered specificity of the 5′ nucleotide, as well as use of the H1 promoter sequence as a bidirectional promoter to express Cas9 nuclease and the gRNA simultaneously. Compositions and methods are also provided for the expression and regulation of gRNA expression in vivo through the use of RNA ribozymes and regulatable aptazymes.
1. A method, the method comprising introducing into a cell a non-naturally occurring CRISPR-Cas system comprising a single vector comprising an H1 bidirectional promoter, wherein the H1 bidirectional promoter comprises:
a) control elements that provide for transcription in one direction of at least one nucleotide sequence encoding a CRISPR-Cas system guide RNA (gRNA), wherein the gRNA hybridizes with a target sequence of the DNA molecule; and
b) control elements that provide for transcription in the opposite direction of a nucleotide sequence encoding a RNA-directed nuclease,
wherein the gRNA targets and hybridizes with the target sequence and directs the RNA-directed nuclease to the DNA molecule, and wherein said system is packaged into a single adeno-associated virus (AAV) particle.
2. The method of claim 1 , wherein the target sequence comprises the nucleotide sequence AN 19 NGG, GN 19 NGG, CN 19 NGG, or TN 19 NGG.
3. The method of claim 1 , wherein the RNA-directed nuclease is a Cas9 protein.
4. The method of claim 3 , wherein the Cas9 protein is codon optimized for expression in the cell and/or is a Type-II Cas9 protein.
5. The method of claim 1 , wherein the cell is a eukaryotic cell optionally selected from the group consisting of (i) a mammalian cell, (ii) a human cell, and/or (iii) a retinal photoreceptor cell.
6. The method of claim 1 , wherein the expression of one or more gene products is decreased.