Component of the MMS22L-TONSL complex, a complex that promotes homologous recombination-mediated repair of double-strand breaks (DSBs) at stalled or collapsed replication forks (    ). The MMS22L-TONSL complex is required to maintain genome integrity during DNA replication ( ). It mediates the assembly of RAD51 filaments on single-stranded DNA (ssDNA): the MMS22L-TONSL complex is recruited to DSBs following histone replacement by histone chaperones and eviction of the replication protein A complex (RPA/RP-A) from DSBs (  ). Following recruitment to DSBs, the TONSL-MMS22L complex promotes recruitment of RAD51 filaments and subsequent homologous recombination (, ). Within the complex, TONSL acts as a histone reader, which recognizes and binds newly synthesized histones following their replacement by histone chaperones (, ). Specifically binds histone H4 lacking methylation at 'Lys-20' (H4K20me0) and histone H3.1 .
Subcellular locations: Nucleus, Chromosome, Cytoplasm
Mainly nuclear (, ). Localizes to DNA damage sites, accumulates at stressed replication forks ( , ). Recruited to stalled or collapsed replication forks following histone replacement by histone chaperones ASF1A and the CAF-1 complex: TONSL acts as a histone reader that recognizes and binds newly synthesized histones .
Expressed in heart, skeletal muscle and tracheal epithelial cells.