RNA-guided genetic silencing systems in bacteria and archaea

  title={RNA-guided genetic silencing systems in bacteria and archaea},
  author={Blake Wiedenheft and Samuel H. Sternberg and Jennifer A. Doudna},
Clustered regularly interspaced short palindromic repeat (CRISPR) are essential components of nucleic-acid-based adaptive immune systems that are widespread in bacteria and archaea. Similar to RNA interference (RNAi) pathways in eukaryotes, CRISPR-mediated immune systems rely on small RNAs for sequence-specific detection and silencing of foreign nucleic acids, including viruses and plasmids. However, the mechanism of RNA-based bacterial immunity is distinct from RNAi. Understanding how small… 
Gene regulation by engineered CRISPR-Cas systems.
Efficient In Vivo Genome Editing Using RNA-Guided Nucleases
It is shown that the CRISPR-Cas system functions in vivo to induce targeted genetic modifications in zebrafish embryos with efficiencies similar to those obtained using zinc finger nucleases and transcription activator–like effector nucleases.
Unravelling the structural and mechanistic basis of CRISPR–Cas systems
This Review summarizes the recent structural and biochemical insights that have been gained for the three major types of CRISPR–Cas systems, which together provide a detailed molecular understanding of the unique and conserved mechanisms of RNA-guided adaptive immunity in bacteria and archaea.
Control of gene expression by CRISPR-Cas systems
The role of these loci in the regulation of gene expression as well as the recent development of synthetic gene regulation using engineered CRISPR-Cas systems are summarized.
CRISPR-mediated adaptive immune systems in bacteria and archaea.
The mechanisms of CRISPR-mediated immunity are reviewed and the ecological and evolutionary implications of these adaptive defense systems are discussed.
Evolution and Ecology of CRISPR
The current understanding of the evolutionary ecology of CRISPR-Cas systems is summarized, their value as model systems to answer fundamental questions concerning host–parasite coevolution are highlighted, and how they can be useful tools for scientists across virtually all disciplines are explained.
Functions and Applications of RNA‐Guided CRISPR‐Cas Immune Systems
The inheritable and hypervariable nature of these loci can be used to track the phylogenetic path of an organism and reveal the evolutionary interplay between hosts and their viruses.
Prokaryotic Argonautes defend genomes against invasive DNA.
The structural biology of CRISPR-Cas systems.


CRISPR interference: RNA-directed adaptive immunity in bacteria and archaea
The mechanisms of CRISPR interference and its roles in microbial physiology and evolution are reviewed and potential applications of this novel interference pathway are discussed.
CRISPR/Cas system and its role in phage-bacteria interactions.
Recent progress made in the CRISPR/Cas system is described, which participates in a constant evolutionary battle between phages and bacteria through addition or deletion of spacers in host cells and mutations or deletion in phage genomes.
CRISPR — a widespread system that provides acquired resistance against phages in bacteria and archaea
The structure and function of this newly recognized antiviral mechanism, together with a group of associated proteins, confer resistance to phages, possibly by an RNA-interference-like mechanism.
CRISPR Provides Acquired Resistance Against Viruses in Prokaryotes
It is found that, after viral challenge, bacteria integrated new spacers derived from phage genomic sequences, and CRISPR provided resistance against phages, and resistance specificity is determined by spacer-phage sequence similarity.
Recognition and maturation of effector RNAs in a CRISPR interference pathway
High-resolution X-ray structures of Cse3 bound to repeat RNAs model both the pre- and post-cleavage complexes associated with processing thePre-crRNA and establish the molecular basis of a specific CRISPR RNA recognition and suggest the mechanism for generation of effector RNAs responsible for gene silencing.
Small CRISPR RNAs Guide Antiviral Defense in Prokaryotes
The results demonstrate that the formation of mature guide RNAs by the CRISPR RNA endonuclease subunit of Cascade is a mechanistic requirement for antiviral defense.
Prokaryotic silencing (psi)RNAs in Pyrococcus furiosus.
These results identify the principal products of the CRISPR loci as small psiRNAs comprised primarily of invader-targeting sequence with perhaps only 5-10 nucleotides ofCRISPR repeat sequence, which are the most abundant CRISpr RNA species in P. furiosus.
Sequence- and Structure-Specific RNA Processing by a CRISPR Endonuclease
The RNA recognition mechanism identified here explains sequence- and structure-specific processing by a large family of CRISPR-specific endoribonucleases.
CRISPR/Cas, the Immune System of Bacteria and Archaea
Clustered regularly interspaced short palindromic repeats (CRISPR) form peculiar genetic loci, which provide acquired immunity against viruses and plasmids by targeting nucleic acid in a sequence-specific manner.