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Recent studies indicate that the DNA recognition domain of transcription activator-like (TAL) effectors can be combined with the nuclease domain of FokI restriction enzyme to produce TAL effector nucleases (TALENs) that, in pairs, bind adjacent DNA target sites and produce double-strand breaks between the target sequences, stimulating non-homologous end-joining and homologous recombination. Here, we exploit the four prevalent TAL repeats and their DNA recognition cipher to develop a 'modular assembly' method for rapid production of designer TALENs (dTALENs) that recognize unique DNA sequence up to 23 bases in any gene. We have used this approach to engineer 10 dTALENs to target specific loci in native yeast chromosomal genes. All dTALENs produced high rates of site-specific gene disruptions and created strains with expected mutant phenotypes. Moreover, dTALENs stimulated high rates (up to 34%) of gene replacement by homologous recombination. Finally, dTALENs caused no detectable cytotoxicity and minimal levels of undesired genetic mutations in the treated yeast strains. These studies expand the realm of verified TALEN activity from cultured human cells to an intact eukaryotic organism and suggest that low-cost, highly dependable dTALENs can assume a significant role for gene modifications of value in human and animal health, agriculture and industry.
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http://dx.doi.org/10.1093/nar/gkr188 | DOI Listing |
Mol Plant
September 2025
College of Life Sciences, Capital Normal University, Beijing, 100048, China; Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing, 100048, China. Electronic address:
In the intricate molecular warfare between plants and pathogens, bacteria deploy sophisticated strategies to subvert host defenses. Xanthomonas oryzae pathogens, which cause devastating bacterial blight (BB) and bacterial leaf streak (BLS) in rice, utilize transcription activator-like effectors (TALEs) to manipulate host gene expression. Secreted by the type III secretion system and translocated by the type III translocon into host cells, TALEs directly bind specific DNA sequences (effector-binding elements, EBEs) in the 5'-terminal untranslated regions (UTRs) or within the promoter regions of host genes to activate transcription of these genes, including SWEETs sugar transporters and negative regulators of plant immunity (Xue et al.
View Article and Find Full Text PDFFEBS J
September 2025
Faculty of Engineering and Natural Sciences, Sabancı University, Istanbul, Turkey.
The CRISPR/Cas9 system has revolutionized molecular biology and gene editing, yet key aspects of its regulation, especially within eukaryotic environments, remain enigmatic. In this Viewpoint article, I will speculate on and explore the provocative hypothesis that Cas9 may possess previously unrecognized effector-like functions when expressed in host cells, potentially shaped by host-mediated post-translational modifications (PTMs). Of particular interest is SUMOylation at lysine 848, a key residue for DNA binding within the catalytic site, raising the possibility that this modification is not incidental, but functionally significant and precisely regulated.
View Article and Find Full Text PDFmSphere
August 2025
Earlham Institute, Norwich Research Park, Norwich, United Kingdom.
Amoeboflagellates of the genus are free-living protists ubiquitously found in soil and freshwater habitats worldwide. They include the "brain-eating amoeba" , an opportunistic pathogen that causes primary amoebic meningoencephalitis, a rare but fatal infection of humans. Beyond their direct pathogenicity, protists can also act as environmental reservoirs for intracellular bacterial pathogens, such as spp.
View Article and Find Full Text PDFExp Mol Med
July 2025
Biomedical Research Division, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Genome engineering has made remarkable strides, evolving from DNA-binding proteins such as zinc fingers and transcription activator-like effectors to CRISPR-Cas systems. CRISPR technology has revolutionized the field through its simplicity and ability to target specific genome regions via guide RNA and Cas proteins. Progress in CRISPR tools-CRISPR nucleases, base editors and prime editors-has expanded the toolkit to induce targeted insertions or deletions, nucleotide conversions and a wider array of genetic alterations.
View Article and Find Full Text PDFMol Plant
September 2025
College of Plant Protection, Shandong Agricultural University, Taian, China. Electronic address:
Plant proteins that belong to the nonexpressor of pathogenesis-related (NPR) gene family are paralogous receptors of the plant defense hormone salicylic acid and essential regulators of hormone-dependent plant immunity against diseases caused by various pathogens. Previous studies have established NPR1 and NPR3 as a transcriptional activator and a transcriptional repressor, respectively, of defense-gene expression to promote and inhibit broad-spectrum resistance against different strains of pathogens. However, the regulatory mechanism that underlies the opposing roles of NPR1 and NPR3 in defense-gene activation remains unclear.
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