Review:
Non Homologous End Joining (nhej)
overall review score: 4.2
⭐⭐⭐⭐⭐
score is between 0 and 5
Non-homologous end joining (NHEJ) is a cellular DNA repair mechanism that directly ligates broken DNA double strands without the need for a homologous template. It is an essential pathway in maintaining genomic stability, especially in non-dividing cells, by quickly repairing double-strand breaks (DSBs). NHEJ plays a critical role in immune system development through V(D)J recombination and influences genome editing techniques such as CRISPR/Cas9.
Key Features
- Rapid DNA repair process that directly joins DNA ends
- Does not require a homologous template for repair
- Involves key proteins including Ku70/80, DNA-PKcs, Artemis, XRCC4, and Ligase IV
- Can be error-prone, leading to insertions or deletions at repair sites
- Active throughout the cell cycle but predominantly in G1 phase
- Fundamental to genomic stability and immune diversity
Pros
- Essential for quick and effective repair of double-strand breaks
- Preserves genome integrity in non-dividing cells
- Facilitates immune system diversification via V(D)J recombination
- Widely conserved across species, highlighting its importance
Cons
- Error-prone nature can introduce mutations leading to genomic instability
- Limited accuracy compared to homologous recombination (HR)
- Inhibition or malfunction can contribute to cancer development
- Not suitable as a precise editing tool without modifications