Cas9 and Cas12 nucleases of class 2 CRISPR-Cas systems provide immunity in prokaryotes through RNA-guided cleavage of foreign DNA. Here we characterize a set of compact CRISPR-Cas12m (subtype V-M) effector proteins and show that they provide protection against bacteriophages and plasmids through the targeted DNA binding rather than DNA cleavage. Biochemical assays suggest that Cas12m effectors can act as roadblocks inhibiting DNA transcription and/or replication, thereby triggering interference against invaders. Cryo-EM structure of Gordonia otitidis (Go) Cas12m ternary complex provided here reveals the structural mechanism of DNA binding ensuring interference. Harnessing GoCas12m innate ability to bind DNA target we fused it with adenine deaminase TadA-8e and showed an efficient A-to-G editing in Escherichia coli and human cells. Overall, this study expands our understanding of the functionally diverse Cas12 protein family, revealing DNA-binding dependent interference mechanism of Cas12m effectors that could be harnessed for engineering of compact base-editing tools.
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http://dx.doi.org/10.1093/nar/gkae016 | DOI Listing |
Anal Chim Acta
February 2025
School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, 450001, China. Electronic address:
Background: DNA methylation catalyzed by various DNA methyltransferases (DNA MTases) is one of the important epigenetic regulations in both eukaryotes and prokaryotes. Therefore, the detection of DNA MTase activity is a vital target and direction in the study of methylation-related diseases.
Results: In this study, an ultrasensitive and robust strategy was developed for DNA MTase activity sensing based on bifunctional probe propelling multipath strand displacement amplification and CRISPR/Cas12a techniques.
J Allergy Clin Immunol
January 2025
Institute of Human Genetics, UMR9002, CNRS and Montpellier University; Montpellier, France; Montpellier University; Montpellier, France; Immunology Department, University Hospital; Nîmes, France. Electronic address:
Background: We have recently shown that, during acute severe COVID-19, SARS-CoV-2 spike protein (S) induces a cascade of events resulting in T cell apoptosis. Indeed, by neutralizing the protease activity of its receptor, ACE2, S induces an increase in circulating Angiotensin II (AngII), resulting in monocytic release of reactive oxygen species (ROS) and programmed T cell death.
Objective: Here, we tested whether SARS-CoV-2 mRNA vaccines, known to cause the circulation of the vaccine antigen, S-protein receptor binding domain (RBD), might trigger the same cascade.
Ecotoxicol Environ Saf
January 2025
MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address:
Plastic pollution has become a common phenomenon. The process of plastic degradation is accompanied by the release of microplastics and plasticizers. However, the coexistence of microplastics and plasticizers on the transfer of antibiotic resistance genes (ARGs) has not been reported until now.
View Article and Find Full Text PDFTransl Oncol
January 2025
Shanghai Ninth People's Hospital, Department of Clinical Laboratory medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, PR China; College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, PR China. Electronic address:
Objectives: The specific role of 3-hydroxyanthranilic acid(3-HAA) in oral squamous cell carcinoma (OSCC) remains unclear. This study investigated the roles of 3-HAA in OSCC and the underlying mechanism.
Materials And Methods: The effects of 3-HAA on OSCC were examined using CCK-8, colony formation, EdU incorporation assays and xenograft mouse model.
Phytomedicine
December 2024
Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100073, China. Electronic address:
Background: Adherence of Helicobacter pylori to the surface of the gastric mucosa is the initial and crucial step for its survival and colonization in the harsh conditions of the stomach. We had previously demonstrated that daphnetin has anti-adhesion effect.
Purpose: This study aims to explore the mechanisms of daphnetin to reduce H.
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