Genome editing offers promising solutions to genetic disorders by editing DNA sequences or modulating gene expression. The clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) technology can be used to edit single or multiple genes in a wide variety of cell types and organisms in vitro and in vivo. Herein, we review the rapidly developing CRISPR/Cas9-based technologies for disease modeling and gene correction and recent progress toward Cas9/guide RNA (gRNA) delivery based on viral and nonviral vectors. We discuss the relative merits of delivering the genome editing elements in the form of DNA, mRNA, or protein, and the opportunities of combining viral delivery of a transgene encoding Cas9 with nonviral delivery of gRNA. We highlight the lessons learned from nonviral gene delivery in the past three decades and consider their applicability for CRISPR/Cas9 delivery. We also include a discussion of bioinformatics tools for gRNA design and chemical modifications of gRNA. Finally, we consider the extracellular and intracellular barriers to nonviral CRISPR/Cas9 delivery and propose strategies that may overcome these barriers to realize the clinical potential of CRISPR/Cas9-based genome editing.
A superhydrophobic fabric coating made of a crosslinked polydimethylsiloxane elastomer, containing well-dispersed hydrophobic silica nanoparticles and fluorinated alkyl silane, shows remarkable durability against repeated machine washes, severe abrasion, strong acid or base, boiling water or beverages and excellent stain resistance.
A fabric coating prepared from a homogeneous mixture of fluorinated‐decyl polyhedral oligomeric silsesquioxane and hydrolyzed fluorinated alkyl silane shows remarkable self‐healing superhydrophobic and superoleophobic properties and excellent durability against UV light, acid, repeated machine washes, and severe abrasion (see picture).
Many infections and stress signals can rapidly activate the NLRP3 inflammasome to elicit robust inflammatory responses. This activation requires a priming step, which is thought to be mainly for upregulating NLRP3 transcription. However, recent studies report that the NLRP3 inflammasome can be activated independently of transcription, suggesting that the priming process has unknown essential regulatory steps. Here, we report that JNK1-mediated NLRP3 phosphorylation at S194 is a critical priming event and is essential for NLRP3 inflammasome activation. We show that NLRP3 inflammasome activation is disrupted in NLRP3-S194A knockin mice. JNK1-mediated NLRP3 S194 phosphorylation is critical for NLRP3 deubiquitination and facilitates its self-association and the subsequent inflammasome assembly. Importantly, we demonstrate that blocking S194 phosphorylation prevents NLRP3 inflammasome activation in cryopyrin-associated periodic syndromes (CAPS). Thus, our study reveals a key priming molecular event that is a prerequisite for NLRP3 inflammasome activation. Inhibiting NLRP3 phosphorylation could be an effective treatment for NLRP3-related diseases.
Here we present the 15 pseudochromosomes of sweet potato, Ipomoea batatas, the seventh most important crop in the world and the fourth most significant in China. By using a novel haplotyping method based on genome assembly, we have produced a half haplotype-resolved genome from ~296 Gb of paired-end sequence reads amounting to roughly 67-fold coverage. By phylogenetic tree analysis of homologous chromosomes, it was possible to estimate the time of two recent whole-genome duplication events as occurring about 0.8 and 0.5 million years ago. This half haplotype-resolved hexaploid genome represents the first successful attempt to investigate the complexity of chromosome sequence composition directly in a polyploid genome, using sequencing of the polyploid organism itself rather than any of its simplified proxy relatives. Adaptation and application of our approach should provide higher resolution in future genomic structure investigations, especially for similarly complex genomes.
A light signal is converted into an electrical one in a single molecule named channelrhodopsin, one of the archaea-type rhodopsins in unicellular green algae. Although highly homologous, two molecules of this family, channelrhodopsin-1 (ChR1) and -2 (ChR2), are distinct in photocurrent properties such as the wavelength sensitivity, desensitization, and turning-on and -off kinetics. However, the structures regulating these properties have not been completely identified. Photocurrents were analyzed for several chimera molecules made by replacing N-terminal segments of ChR2 with the homologous counterparts of ChR1. We found that the wavelength sensitivity of the photocurrent was red-shifted with negligible desensitization and slowed turning-on and -off kinetics when replacement was made with the segment containing the fifth transmembrane helix of ChR1. Therefore, this segment is involved in the determination of photocurrent properties, the wavelength sensitivity, and the kinetics characterizing ChR1 and ChR2. Eight amino acid residues differentiating this segment were exchanged oneby-one, and the photocurrent properties of each targeted mutant ChR2 were further analyzed. Among them, position Tyr 226 (ChR1)/Asn 187 (ChR2) is one of the molecular determinants involved in the wavelength sensitivity, desensitization, and turning-on and -off kinetics. It is suggested that these amino acid residues directly or indirectly interact with the chromophore as well as with the protein structure determining the photocurrent kinetics. Some of the chimera channelrhodopsins are suggested to have several advantages over the wild-type ChR2 in the introduction of light-induced membrane depolarization for the purpose of artificial stimulation of neurons in vivo and visual prosthesis for photoreceptor degeneration.
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