Related Experiment Video
Updated: Jun 28, 2026

Using Next Generation Sequencing to Identify Mutations Associated with Repair of a CAS9-induced Double Strand Break Near the CD4 Promoter
Published on: March 31, 2022
Cernunnos/XLF: a new player in DNA double-strand break repair
Ken-ichi Yano1, Keiko Morotomi-Yano, Hidenori Akiyama
1Bioelectrics Research Center, Kumamoto University, Kurokami 2-39-1, Kumamoto 860-8555, Japan. yanoken@kumamoto-u.ac.jp
Abstract:
Non-homologous end-joining (NHEJ) is the predominant repair pathway for DNA double-strand breaks (DSBs) in vertebrates and also plays a crucial role in V(D)J recombination of immunoglobulin genes. Cernunnos/XLF is a newly identified core factor for NHEJ, and its defect causes a genetic disease characterized by neural disorders, immunodeficiency and increased radiosensitivity. Cernunnos/XLF has at least two distinct functions in NHEJ. Cernunnos/XLF interacts with and stimulates the XRCC4/DNA ligase IV complex, which acts at the final ligation step in NHEJ. In living cells, Cernunnos/XLF quickly responds to DSB induction and accumulates at damaged sites in a Ku-dependent but XRCC4-independent manner. These observations indicate that Cernunnos/XLF plays a unique role in bridging damage sensing and DSB rejoining steps of NHEJ. Recent crystallographic analyses of the homodimeric Cernunnos/XLF protein provide structural insights into the Cernunnos/XLF functions. These studies offer important clues toward understanding the molecular mechanism for NHEJ-defective diseases.
Related Concept Videos
Fixing Double-strand Breaks
Fixing Double-strand Breaks
Nucleotide Excision Repair
Nucleotide Excision Repair
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Homologous Recombination

