Researchers at the University of California, Davis have developed a new epigenetic editing system that overcomes packaging limitations of viral delivery systems and can be used for multiplexed epigenetic editing of a genome.

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RNA-binding proteins (RBPs) play essential roles in gene expression and other cellular functions. Thus their identification and the understanding of their mechanisms of action and regulation is key to unraveling physiology and disease. To measure translation efficiency and different steps of ribosome recruitment, the state of the art is ribosome profiling (or Ribo‐seq) and polysome profiling which uses millions of cells, sucrose gradients, centrifugation and often requires the removal of ribosomal RNA as part of the sequencing library preparation as it contaminates more than 50% of most ribosome/polysome libraries. Also, we cannot distinguish full length isoforms here, as the ribosome‐fragments are short.

The inventors have developed optimized methods for using virus-like particles for the co-delivery of Cas9 ribonucleoprotein complexes and: a lentiviral genome that encodes a large transgene, such as a chimeric angtigen receptor (CAR) transgene a lentiviral genome that does not encode a sgRNA expression cassette a method for nucleofecting VLPs + homology directed repair (HDR) donor template together to enhance HDR in treated cells  

Researchers at the University of California, Davis have identified specific genetic modifications to plants that impart a variety of advantages based on modulating the presence of suberin

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resent strategies aimed to target and manipulate RNA in living cells mainly rely on the use of antisense oligonucleotides (ASO) or engineered RNA binding proteins (RBP). Although ASO therapies have been shown great promise in eliminating pathogenic transcripts or modulating RBP binding, they are synthetic in construction and thus cannot be encoded within DNA. This complicates potential gene therapy strategies, which would rely on regular administration of ASOs throughout the lifetime of the patient. Furthermore, they are incapable of modulating the genetic sequence of RNA. Although engineered RBPs such as PUF proteins can be designed to recognize target transcripts and fused to RNA modifying effectors to allow for specific recognition and manipulation, these constructs require extensive protein engineering for each target and may prove to be laborious and costly. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0in; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Researchers at the University of California, Davis have developed microorganisms with increased alcohol tolerance by modifying the organisms’ pntAB locus through expression of one or both of its pntA/pntB genes.

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PCR amplification is widely used in basic biological research and medical diagnostic tests for various infectious diseases, and is a powerful tool for nucleic acid detection. Nucleic acid extraction is an important part of the overall workflow in PCR-based viral infection test, since its function is to separate out viral nucleic acid from the many other biological components in a nasal swab-derived sample. UC Berkeley researchers have developed a method for single-stranded nucleic acid extraction from complex biofluids with DNA-wrapped carbon nanotubes. Large viral single-stranded nucleic acids can be captured by corresponding DNA-wrapped carbon nanotubes and can be concentrated for subsequent polymerase chain reaction (PCR) amplification. This method can extract nucleic acids without complicated manufacturing and experimental processes, can generate higher extraction yields than a conventional commercial PCR kit, and fits into the current PCR workflow while requiring minimal chemical reagents.  

The inventors have developed two new CasX gene-editing platforms (DpbCasXv2 and PlmCasXv2) through rationale structural engineering of the CasX protein and gRNA, which yield improved in vitro and in vivo behaviors. These platforms dramatically increase DNA cleavage activity and can be used as the basis for further improving CasX tools.The RNA-guided CRISPR-associated (Cas) protein CasX has been reported as a fundamentally distinct, RNA-guided platform compared to Cas9 and Cpf1. Structural studies revealed structural differences within the nucleotide-binding loops of CasX, with a compact protein size less than 1,000 amino acids, and guide RNA (gRNA) scaffold stem. These structural differences affect the active ternary complex assembly, leading to different in vivo and in vitro behaviors of these two enzymes.

Csm6 constitutes a family of enzymes that are activated by cyclic oligoadenylates (cA(n)) or linear oligoadenylates with a 2´,3´-cyclic phosphate termini (A(n)>P). Cleavage of a nucleic acid sequence by an RNase to generate a linear oligoadenylate with exactly 4 or 6 A’s and the 2´,3´-cyclic phosphate terminus (A4>P or A6>P) leads to activation of Csm6/Csx1 for cleavage of a fluorescent RNA reporter. The linear A4 or A6 can be incorporated into an RNA sequence (e.g. A4-U6 or A6-U5) such that activation of Csm6 only occurs upon removal of the U-containing sequence by Cas13a, a programmable RNA-guided RNase that preferentially cleaves the phosphodiester bond that is 5’ to U’s and generates products with 2´,3´-cyclic phosphates. Csm6 is normally inactivated through self-cleavage of its activator, leading to low sensitivity when coupled with a Cas13-based RNA detection system or a Cas13-Csm6 feed-forward detection system.In this invention, the 2’-hydroxyl of the ribose in the second A in the linear A4 or the third A in the linear A6 is replaced with a 2’-fluorine (fA). This single 2’-fluoro modified RNA oligonucleotide (A-fA-AA>P or AA-fA-AAA>P) would bind and activate Csm6/Csx1 with fast kinetics and prevent degradation of the linear oligoadenylate by Csm6/Csx1. This single 2´-fluoro-modified polyA activator could be followed by any sequence to couple activation of Csm6 to a second enzyme. The purpose of this invention is to generate sustained activation of Csm6, when coupled with a Cas13 RNA detection system. In one iteration of this invention, the modified activator is followed by a linear chain of U’s, and is thus cleavable by Cas13 upon Cas13’s activation by a complementary sequence of RNA. Other nucleotides (e.g. C, A) or 2´-deoxy modifications can also be included 3´ to the first U to restrict the cleavage of Cas13a to the precise site that is required to release the single 2’-fluoro modified An>P (e.g. A-fA-AAUCCCCCC...). This activator leads to increased sensitivity and kinetics in RNA detection when coupled with Cas13. In another iteration of this invention, the modified activator is followed by a linear chain of C’s (Cn). This substrate can be acted upon by a pre-activated Csm6 (e.g. by Cas13) to produce A-fA-AA>P or AA-fA-AAA>P, which initiates a sustained feed-forward loop and prevents self-degradation of the activator by Csm6. Restricting the cleavage site of this activator by addition of chemical modifications (such as 2’-deoxy) on positions other than the cleavage site leads to a precise cut by Csm6. This activator can be combined with the previous iteration to generate even higher sensitivity and kinetics in RNA detection than the previous iteration alone. Cleavage of a fluorescent and colorimetric RNA reporter by the highly activated Csm6 in either iteration would then generate a detectable signal. In addition, nucleotides with modified bases that are not recognized by Csm6 or Cas13 may also be used in the cleavable “tail” of the activators to avoid competition with the RNA reporter or other activators in the system. Overall, the purpose of this invention is to enable elevated activation and kinetics of Csm6 when coupled with a Cas13 RNA detection system or a feed-forward reaction with Csm6 and Cas13. This could be used in low-copy detection of any type of single-stranded RNA, including viral RNA genomes, viral RNA transcripts, and cellular RNA transcripts. In addition, these activators could also be used with the related family of enzymes known as Csx1.

CRISPR-Cas systems include Cas proteins, which are involved in acquisition, targeting and cleavage of foreign DNA or RNA, and a guide RNA(s), which includes a segment that binds Cas proteins and a segment that binds to a target nucleic acid. For example, Class 2 CRISPR-Cas systems comprise a single Cas protein bound to a guide RNA, where the Cas protein binds to and cleaves a targeted nucleic acid. The programmable nature of these systems has facilitated their use as a versatile technology for use in modification of target nucleic acid.   UC Berkeley researchers have discovered a novel family of proteins (CasVariPhi) that utilize a guide RNA to perform RNA-directed cleavage of nucleic acids. Viral and microbial (cellular) genomes were assembled from a variety of environmental and animal microbiome sources, and variants of a novel and previously unknown Cas protein family were uncovered from the sequences decoded. 

CRISPR-Cas systems include Cas proteins, which are involved in acquisition, targeting and cleavage of foreign DNA or RNA, and a guide RNA(s), which includes a segment that binds Cas proteins and a segment that binds to a target nucleic acid. For example, Class 2 CRISPR-Cas systems comprise a single Cas protein bound to a guide RNA, where the Cas protein binds to and cleaves a targeted nucleic acid. The programmable nature of these systems has facilitated their use as a versatile technology for use in modification of target nucleic acid.   UC Berkeley researchers have discovered a novel family of proteins (CasOmega) that utilize a guide RNA to perform RNA-directed cleavage of nucleic acids. Viral and microbial (cellular) genomes were assembled from a variety of environmental and animal microbiome sources, and variants of a novel and previously unknown Cas protein family were uncovered from the sequences decoded. 

CRISPR-Cas systems include Cas proteins, which are involved in acquisition, targeting and cleavage of foreign DNA or RNA, and a guide RNA(s), which includes a segment that binds Cas proteins and a segment that binds to a target nucleic acid. For example, Class 2 CRISPR-Cas systems comprise a single Cas protein bound to a guide RNA, where the Cas protein binds to and cleaves a targeted nucleic acid. The programmable nature of these systems has facilitated their use as a versatile technology for use in modification of target nucleic acid.   UC Berkeley researchers have discovered a novel family of proteins (CasTheta) that utilize a guide RNA to perform RNA-directed cleavage of nucleic acids. Viral and microbial (cellular) genomes were assembled from a variety of environmental and animal microbiome sources, and variants of a novel and previously unknown Cas protein family were uncovered from the sequences decoded. 

CRISPR-Cas systems include Cas proteins, which are involved in acquisition, targeting and cleavage of foreign DNA or RNA, and a guide RNA(s), which includes a segment that binds Cas proteins and a segment that binds to a target nucleic acid. For example, Class 2 CRISPR-Cas systems comprise a single Cas protein bound to a guide RNA, where the Cas protein binds to and cleaves a targeted nucleic acid. The programmable nature of these systems has facilitated their use as a versatile technology for use in modification of target nucleic acid.   UC Berkeley researchers have discovered a novel family of compact proteins (CasGamma) with a RuvC-like domain in the C-terminal end of the protein. These proteins are able to cleave nucleic acids. Viral and microbial (cellular) genomes were assembled from a variety of environmental and animal microbiome sources, and variants of a novel and previously unknown Cas protein family were uncovered from the sequences decoded. These CasGamma proteins utilize a guide RNA to perform RNA-directed cleavage of nucleic acids.  

The eukaryotic ribosome is composed of 79 ribosomal protein – large (RPL) and ribosomal protein – small (RPS) subunit proteins that interweave with 4 highly structured RNAs (5S, 5.8S, 18S, and 28S rRNAs) to form the final translation-capable ribonucleoprotein. Thus, quantification of ribosome-associated RNA is highly similar to profiling of RNAs associated with other RNA binding proteins. We recently described the development of enhanced crosslinking and immunoprecipitation (eCLIP), a method to profile RNAs bound by an RNA binding protein of interest that showed thousand-fold improved recovery of protein-bound RNA [Van Nostrand et al 2016]. Van Nostrand EL, Pratt GA, Shishkin AA, Gelboin-Burkhart C, Fang MY, Sundararaman B, Blue SM, Nguyen TB, Surka C, Elkins K, et al: Robust transcriptome-wide discovery of RNA-binding protein binding sites with enhanced CLIP (eCLIP). Nat Methods 2016, 13:508-514. https://pubmed.ncbi.nlm.nih.gov/27018577/

Green algae have been promoted as vehicles for the production of biofuels, pharmaceuticals, food additives, vaccines, and for toxic substance remediation, and many plants are the focus of efforts to produce drought tolerant, pest resistant, or more nutritious crops. Many of these engineering efforts rely on expression of multiple transgenes (e.g. in a multistep metabolic pathway to avoid accumulation of a toxic intermediate). It can also be useful to produce two or more proteins in a particular stoichiometry, as in a heterodimer that requires equimolar production of two polypeptides. Whether the goal is to express one transgene, or several, most efforts to transform plants and algae require cotransformation of the gene of interest with a selectable marker, such as a gene that confers resistance to a drug or herbicide, or complements an auxotrophy. Unfortunately, commonly used methods for co-transformation of algae and other plants are very inefficient. UC Berkeley investigators have developed a method for polycistronic gene expression,  and show how to achieve this using the organism's own sequences, without recourse to viral elements or other foreign elements, which is important for any technology where bioproducts are generated, since these may be used on humans (cosmetics) or in humans (food additives), especially crop technology.

Brief description not available

This invention leverages the nuclease activity of CRISPR proteins for the direct, sensitive detection of specific nucleic acid sequences. This all-in-one detection modality includes an internal Nuclease Chain Reaction (NCR), which possesses an amplifying, feed-forward loop to generate an exponential signal upon detection of a target nucleic acid.Cas13 or Cas12 enzymes can be programmed with a guide RNA that recognizes a desired target sequence, activating a non-specific RNase or DNase activity. This can be used to release a detectable label. On its own, this approach is inherently limited in sensitivity and current methods require an amplification of genetic material before CRISPR-base detection. 

Viral infection is a multistep process involving complex interplay between viral life cycle and host immunity. One defense mechanism that hosts use to protect cells against the virus are nucleic-acid-mediated surveillance systems, such as RNA interference-driven gene silencing and CRISPR-Cas mediated gene editing. Another important stage for host cells to combat virus replication is translational regulation, which is particular important for the life cycle of RNA viruses, such as Hepatitis C virus and Coronavirus.  While efforts to characterize structural features of viral RNA have led to a better understanding of translational regulation, no systematical approaches to identify important host genes for controlling viral translation have been developed and little is known about how to regulate host-virus translational interaction to prevent and treat infections caused by RNA viruses.   UC Berkeley researchers have developed a high-throughput platform using CRISPR-based target interrogation to identify new therapeutics targets or repurposed drug targets for blocking viral RNA translation.  The new kits can also be used to identify important domains within target proteins that are required for regulating (viral RNA translation) and can inform drug design and development for treating RNA viruses.

Efficient super-Mendelian inheritance of transgenic insertional elements has been demonstrated in flies, mosquitoes, yeast, and mice. While numerous potentially impactful applications of such so-called gene-drive systems have been proposed they are currently limited to copying relatively large DNA cargo sequences (~1-10 Kb). Many desired genetic traits (e.g., drought tolerance in plants, crop yield, pest-resistance, or insecticide sensitivity), however, result from allelic variants altering only one or a few base pairs. An efficient system for super-Mendelian inheritance of such subtle genetic variants would accelerate a wide array of efforts to disseminate favorable traits throughout populations, or to assemble complex genotypes consisting of point-mutant alleles in combination with insertional transgenes for a multitude of research and applied purposes.

In this invention, the HNH domain of a Cas9 is replaced by a domain that could have diverse enzymatic activities. This invention enables engineering of Cas9 chimeras that possess novel, conformation-sensitive enzymatic activity to perform specific genome editing in vitro, in vivo, and ex vivo.Prior to this invention, all of the strategies to engineer Cas9 fusion proteins and provide Cas9 with non-natural enzymatic activity for genome manipulations were engineered by fusing specific domains to the N- or C-terminus of Cas9 via long and flexible linkers, or through domain insertion approach. The disadvantages of these synthetic Cas9 chimeras are that the attached domain is on the long flexible linker, and it is very dynamic. Thus, these fusions have a broad activity window and they are large, which makes it difficult to deliver them to the cells. 

Researchers at the University of California, Davis have developed a viral amplicon-based vector system for heterologous protein expression and production in plants.