Related Experiment Video
Updated: Jul 24, 2025

09:23
Delivery of the Cas9/sgRNA Ribonucleoprotein Complex in Immortalized and Primary Cells via Virus-like Particles "Nanoblades"
Published on: March 31, 2021
5.0K
Programmable RNA-guided endonucleases are widespread in eukaryotes and their viruses
Kaiyi Jiang1,2, Justin Lim1, Samantha Sgrizzi1
1McGovern Institute for Brain Research at MIT, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Biorxiv : the Preprint Server for Biology
|July 3, 2023
Summary
Scientists discovered HERMES, novel RNA-guided nucleases in eukaryotes derived from prokaryotic TnpB proteins. These systems are adapted for eukaryotic cells and show potential for genome editing applications.
Area of Science:
- Molecular Biology
- Genetics
- Biotechnology
Background:
- TnpB proteins are prokaryotic RNA-guided nucleases linked to IS200/605 transposons.
- Eukaryotic homologs, Fanzors, were identified but their function remained unknown.
Approach:
- Searched eukaryotic genomes and viruses for TnpB homologs, identifying numerous RNA-guided nucleases.
- Reconstructed the evolutionary history, renaming them Horizontally-transferred Eukaryotic RNA-guided Mobile Element Systems (HERMES).
- Conducted biochemical and cellular assays to determine HERMES activity and function.
Key Points:
- HERMES are widespread in eukaryotes, often associated with mobile genetic elements, and show extensive adaptation to eukaryotic cells (e.g., nuclear localization, intron capture).
- HERMES utilize adjacent non-coding RNAs for RNA-guided double-stranded DNA cleavage.
- These nucleases possess a rearranged RuvC catalytic domain and lack collateral cleavage activity.
Conclusions:
- HERMES represent a novel class of eukaryotic RNA-guided nucleases with a unique evolutionary origin.
- Demonstrated HERMES' potential for genome editing in human cells.
- Highlights the biotechnological applications of these naturally occurring eukaryotic systems.
Related Concept Videos
CRISPR and crRNAs
17.1K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
17.1K
Ribozymes
12.3K
The term ribozyme is used for RNA that can act as an enzyme. Ribozymes are mainly found in selected viruses, bacteria, plant organelles, and lower eukaryotes. Ribozymes were first discovered in 1982 when Tom Cech’s laboratory observed Group I introns acting as enzymes. This was shortly followed by the discovery of another ribozyme, Ribonulcease P, by Sid Altman’s laboratory. Both Cech and Altman received the Nobel Prize in chemistry in 1989 for their work on ribozymes.
Ribozymes can...
Ribozymes can...
12.3K
Restriction Enzymes
31.0K
Restriction enzymes are bacterial enzymes used to cut DNA in a sequence-specific manner. To cleave DNA, they bind to specific palindromic sequences called restriction sites. Such palindromic DNA sequences or inverted repeats are commonly found in regions of functional significance, such as the origin of replication, gene operator sites, and regions containing transcription termination signals.
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
31.0K
Viruses with RNA Genomes
58
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
58
CRISPR/Cas9 Genome Editing
73
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
73
Retroviruses
12.4K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.4K

