Prokaryotic type II CRISPR-Cas systems can be adapted to enable targeted genome modifications across a range of eukaryotes. Here we engineer this system to enable RNA-guided genome regulation in human cells by tethering transcriptional activation domains either directly to a nuclease-null Cas9 protein or to an aptamer-modified single guide RNA (sgRNA). Using this functionality we developed a transcriptional activation-based assay to determine the landscape of off-target binding of sgRNA:Cas9 complexes and compared it with the off-target activity of transcription activator-like (TALs) effectors. Our results reveal that specificity profiles are sgRNA dependent, and that sgRNA:Cas9 complexes and 18-mer TAL effectors can potentially tolerate 1-3 and 1-2 target mismatches, respectively. By engineering a requirement for cooperativity through offset nicking for genome editing or through multiple synergistic sgRNAs for robust transcriptional activation, we suggest methods to mitigate off-target phenomena. Our results expand the versatility of the sgRNA:Cas9 tool and highlight the critical need to engineer improved specificity.
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http://dx.doi.org/10.1038/nbt.2675 | DOI Listing |
Front Pharmacol
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Institute of Pharmaceutical Chemistry, Goethe University, Frankfurt, Germany.
5-Lipoxygenase (5-LO), encoded by the gene , is implicated in several pathologies. As key enzyme in leukotriene biosynthesis, 5-LO plays a central role in inflammatory diseases, but the 5-LO pathway has also been linked to development of certain hematological and solid tumor malignancies. Of note, previous studies have shown that the leukemogenic fusion protein MLL-AF4 strongly increases gene promoter activity.
View Article and Find Full Text PDFFront Immunol
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Department of Immunology, Erasmus University Medical Center, Rotterdam, Netherlands.
Introduction: Bryostatin-1, a potent agonist of the protein kinase C, has been studied for HIV and cancer therapies. In HIV research, it has shown anti-HIV effects during acute infection and reactivation of latent HIV in chronic infection. As effective CD8+ T cell responses are essential for eliminating reactivated virus and achieving a cure, it is important to investigate how bryostatin-1 affects HIV-specific CD8+ T cells.
View Article and Find Full Text PDFMol Oncol
January 2025
Division of Molecular Genome Analysis, German Cancer Research Center, Heidelberg, Germany.
Colorectal cancer (CRC) patients with microsatellite-stable (MSS) tumors are mostly treated with chemotherapy. Clinical benefits of targeted therapies depend on mutational states and tumor location. Many tumors carry mutations in KRAS proto-oncogene, GTPase (KRAS) or B-Raf proto-oncogene, serine/threonine kinase (BRAF), rendering them more resistant to therapies.
View Article and Find Full Text PDFJ Neuroinflammation
January 2025
Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
Background: Tick-borne encephalitis (TBE) is the most common tick-borne viral infection in Eurasia. Outcomes range from asymptomatic infection to fatal encephalitis, with host genetics likely playing a role. BALB/c mice have intermediate susceptibility to TBE virus (TBEV) and STS mice are highly resistant, whereas the recombinant congenic strain CcS-11, which carries 12.
View Article and Find Full Text PDFMol Med
January 2025
Center for Autoimmune Musculoskeletal and Hematopoietic Diseases, Institute of Molecular Medicine, The Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, Manhasset, New York, 11030, USA.
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