Systems and methods for modulating CRISPR activity
Provided herein are polynucleotides comprising sequence configured to bind to a CRISPR effector protein. Modulation of one or more modifications of the polynucleotides can be used to tune the activity of CRISPR effector proteins complexed with the polynucleotides.
1. A CRISPR OFF polynucleotide comprising:
(a) a guide sequence configured to anneal to a target sequence in a target nucleic acid molecule;
(b) a sequence configured to bind to a CRISPR enzyme; and
(c) a cleavable linker positioned at position 57 and/or 74 in the sequence configured to bind to the CRISPR enzyme wherein position 1 is at a 5′ end of the guide sequence and positions are counted from 5′ to 3′, and wherein the CRISPR OFF polynucleotide is inactivated when the cleavable linker is cleaved.
2. The CRISPR OFF polynucleotide of claim 1 , wherein the cleavable linker is a photocleavable linker.
3. The CRISPR OFF polynucleotide of claim 1 (c), wherein the photocleavable linker is cleaved by visible light.
4. The CRISPR OFF polynucleotide of claim 1 (c), wherein the photocleavable linker is cleaved by ultraviolet (UV) light.
5. The CRISPR OFF polynucleotide of claim 1 (c), wherein the photocleavable linker comprises a compound of Formula:
wherein
* indicates a point of attachment to H, or a first nucleotide; and
** indicates a point of attachment to OH, or a second nucleotide.
6. The CRISPR OFF polynucleotide of claim 1 (c), wherein the photocleavable linker comprises a compound of Formula:
wherein:
R 1 , R 2 , R 3 , R 4 , and R 5 are each independently selected from H, alkyl, substituted alkyl, alkoxy, alkenyl, alkynyl, haloalkyl, haloalkoxy, alkoxyalkyl, amino, aminoalkyl, halo, cyano, hydroxy, hydroxyalkyl, heteroalkyl, C-carboxy, O-carboxy, C-amido, N-amido, nitro, sulfonyl, sulfo, sulfino, sulfonate, S-sulfonamido, N-sulfonamido, optionally substituted carbocyclyl, optionally substituted aryl, optionally substituted heteroaryl and optionally substituted heterocyclyl;
alternatively, two or more of R 1 , R 2 , R 3 , and R 4 , together with the atoms to which they are attached form a ring or ring system selected from optionally substituted 5- to 10-membered heteroaryl, optionally substituted 5- to 10-membered heterocyclyl, and optionally substituted C 5-10 carbocycle; and
m is an integer selected from 2 to 10; and
X is selected from O, S, or dicyanomethylene; and
* indicates a point of attachment to H, or a first nucleotide; and
** indicates a point of attachment to OH, or a second nucleotide.
7. The CRISPR OFF polynucleotide of claim 1 (c), wherein the CRISPR OFF polynucleotide further comprises a photocaging group.
8. The CRISPR OFF polynucleotide of claim 7 , wherein the photocaging group is an ortho-nitrobenzyl group.
9. The CRISPR OFF polynucleotide of claim 1 , wherein the cleavable linker is positioned at position 57 and 74, wherein position 1 is at a 5′ end of the guide sequence, and positions are counted from 5′ to 3′.