The present disclosure provides compositions with a modulating gene expression and methods for modulating transcription.

The invention provides novel CRISPR/Cas compositions and uses thereof for targeting nucleic acids. In particular, the invention provides non-naturally occurring or engineered RNA-targeting systems comprising a novel RNA-targeting Cas13c, Cas13d, Cas13e, or Cas 13f effector protein, and at least one targeting nucleic acid component such as a guide RNA (gRNA) or crRNA. The novel Cas effector proteins are among the smallest of the known Cas effector proteins, at about 800-900 amino acids in size, and are thus uniquely suitable for delivery using vectors of small capacity, such as an AAV vector.

The present invention features fusion polypeptides comprising an RNA binding polypeptide operationally linked to an RNA modifying enzyme (e.g., adenosine deaminase, cytidine deaminase), and methods of use therefore.

Provided are fusion proteins and related molecules useful for conducting base editing with reduced or no off-target mutations. The fusion protein may include a first fragment comprising a nucleobase deaminase or a catalytic domain thereof, a second fragment comprising a nucleobase deaminase inhibitor, and a protease cleavage site between the first fragment and the second fragment. Also provided are improved prime editing systems, including prime editing guide RNA with improved stability.

Compositions and methods comprising novel deaminase polypeptides for targeted editing of nucleic acids are provided. Compositions comprise deaminase polypeptides. Also provided are fusion proteins comprising a DNA-binding polypeptide and a deaminase of the invention. The fusion proteins include RNA-guided nucleases fused to deaminases, optionally in complex with guide RNAs. Compositions also include nucleic acid molecules encoding the deaminases or the fusion proteins. Vectors and host cells comprising the nucleic acid molecules encoding the deaminases or the fusion proteins are also provided.

Disclosed herein include methods, compositions, and kits suitable for use in the measurement of the states of living cells across time. There are provided, in some embodiments, RNA exporter proteins comprising an RNA-binding domain, a membrane-binding domain, and an interaction domain capable of nucleating self-assembly. Disclosed herein include polynucleotides encoding reporter RNA molecule(s). In some embodiments, a plurality of RNA exporter proteins are capable of self-assembling into lipid-enveloped nanoparticles (LNs) secreted from a reporter cell in which the RNA exporter proteins are expressed, thereby generating a population of LNs comprising exported reporter RNA molecule(s).

Disclosed herein include methods, compositions, and kits suitable for use in the delivery of polyribonucleotides and circuits. There are provided, in some embodiments, RNA exporter proteins comprising an RNA-binding domain, a membrane-binding domain, and an interaction domain capable of nucleating self-assembly. Disclosed herein include polynucleotides encoding cargo RNA molecule(s). In some embodiments, a plurality of RNA exporter proteins are capable of self-assembling into lipid-enveloped nanoparticles (LNs) secreted from a sender cell in which the RNA exporter proteins are expressed, thereby generating a population of LNs comprising a fusogen and exported cargo RNA molecule(s).

The present disclosure provides compositions with a modulating gene expression and methods for modulating transcription.

The invention described herein provides compositions and reagents for assembling a tripartite complex at a specific location of a target DNA. The invention also provides methods for using the complex to, for example, label a specific genomic locus, to regulate the expression of a target gene, or to create a gene regulatory network.

The present disclosure provides improved adenosine base editors (ABE) that have an expanded range of PAM sequence recognition capability (i.e., recognition of non-canonical ′5-NGG-′3 PAM sequence). In addition, the present disclosure provides improved cytidine base editors (CBE) and adenosine base editors (ABE) comprising circular permutant variants of Cas9 (CP-Cas9) with an increased window of base editing within the protospacer sequence (e.g., from about 4-5 nucleotides to up to about 8-9 nucleotides) and even outside of the protospacer sequence.