The molecular basis and disease relevance of non-homologous DNA end joining

Area of Science:

• Molecular Biology
• Genetics
• Immunology

Background:

• Non-homologous DNA end joining (NHEJ) is the primary pathway for repairing DNA double-strand breaks (DSBs).
• NHEJ is crucial for V(D)J recombination, essential for adaptive immunity.
• Defective NHEJ leads to genomic instability, radiosensitivity, and immune deficiencies.

Purpose of the Study:

• To review recent advances in understanding NHEJ mechanisms, focusing on synapsis.
• To integrate current knowledge on DNA end processing, synapsis, and ligation in NHEJ.
• To discuss the implications of NHEJ dysfunction in human diseases.

Main Methods:

• Literature review of recent findings on NHEJ.
• Integration of data on DNA repair pathway choice.
• Analysis of mechanisms underlying NHEJ synapsis, end processing, and ligation.

Main Results:

• Synapsis, the juxtaposition of DNA ends, is a critical and multifaceted step in NHEJ.
• Multiple mechanisms contribute to NHEJ synapsis, similar to DNA end processing.
• Failures in various NHEJ steps can lead to human genetic disorders and cancer.

Conclusions:

• Understanding NHEJ mechanisms, particularly synapsis, is key to comprehending its role in genome stability and immunity.
• Dysregulation of NHEJ contributes to human diseases, highlighting its therapeutic relevance.